1,225 results on '"uhmwpe"'
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2. Ballistic resistance of biomimetic ceramic composite armor: An integrated analysis of impact dynamics and structural response
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Ma, Ming-hui, Wu, Yi-ding, Yu, Yi-lei, Lu, Wen-cheng, and Gao, Guang-fa
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- 2024
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3. Effects of various manufacturing parameters and test temperature and crosshead displacement rate on the peel resistance of UHMWPE composites
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Banabila, Omar, Alahmed, Noora, Alameri, Rubayea, Santiago, Rafael, Khan, Kamran A., and Cantwell, Wesley J.
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- 2025
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4. Enhancing ballistic performance: Effect of polyurea coating on backface deformation of UHMWPE laminates
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Wang, Lei, Kong, Jiahao, Chu, Dongyang, Wang, Yifan, Wang, Tao, and Liu, Zhanli
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- 2025
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5. Microstructure and Corrosion Resistance of Composite Based on Ultra-High Molecular Weight Polyethylene in Acidic Media.
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Skakov, Mazhyn, Bayandinova, Moldir, Kozhakhmetov, Yernat, and Tuyakbaev, Bauyrzhan
- Abstract
In this work, the effect of an acidic environment on the structure of composite samples based on ultra-high molecular weight polyethylene (UHMWPE) modified with mineral filler in the form of diabase (DB) is studied. The stability of samples was investigated in solutions of sulfuric (H₂SO₄) and hydrochloric (HCl) acids with concentrations of 10 vol% and 20 vol% at room temperature for 16 weeks. It was found that the introduction of 10 wt% DB into the UHMWPE matrix significantly increases the resistance of the composite sample to aggressive media, which is confirmed by the minimum degree of swelling compared to pure UHMWPE and composites with higher filler content. Scanning electron microscopy (SEM) demonstrated a uniform distribution of DB in the sample structure and the absence of defects such as agglomeration and cracks. The methods of infrared spectroscopy (IRS) and X-ray structural analysis (XRD) revealed a decrease in the degree of crystallinity of the samples after acid exposure, but no significant changes in the chemical structure of the materials were recorded, which confirms their resistance to chemical degradation. The best chemical resistance was demonstrated by composites containing 10 wt% DB, which is associated with the formation of a barrier structure preventing the diffusion of acids. The obtained results indicate the promising application of UHMWPE with DB filler to create samples resistant to aggressive media. [ABSTRACT FROM AUTHOR]
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- 2025
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6. Characterization and Rheological Properties of Ultra-High Molecular Weight Polyethylenes.
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Malkin, Alexander Ya., Ladygina, Tatyana A., Gusarov, Sergey S., Dudka, Dmitry V., and Mityukov, Anton V.
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RHEOLOGY , *HARMONIC oscillators , *MATERIAL plasticity , *VISCOUS flow , *SHEARING force - Abstract
The molecular characteristics and rheological properties of three UHMWPE samples were investigated. The high-temperature GPC method was used for characterizing UHMWPE samples used. The interpretation of the measurement results was based on calibration using the PS standard and the approximation of the PS data by linear and cubic polynomials, as well as on the data for linear PE. The assessment of the average MW and MWD depends on the choice of calibration method, so that different methods give different results. Only the results obtained using PS with cubic approximation are close to the characteristics offered by the manufacturer. It was also shown that the obtained MW characteristics depend on the dissolution time. The reason for this may be the presence of any processing-aid compounds or destruction of macromolecules. Measurements of the rheological properties were performed in creep modes for a wide range of shear stresses and harmonic oscillations. It was shown that even at 210 °C, UHMWPE does not flow, and the observed irreversible deformations are due to the plasticity of the polymer, i.e., UHMWPE is in an elastic–plastic state. The ultimate plastic deformations drop sharply with increasing MW of the polymer. The plasticity modulus for the highest molecular weight UHMWPE samples does not depend on stress. Measurements of viscoelastic characteristics confirmed that the terminal region of viscous flow cannot be reached under any conditions. Increasing the duration of holding the polymer at high temperature leads not to flow, but to the destruction of macromolecules. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Surface Modification of Ultra-High-Molecular-Weight Polyethylene and Applications: A Review.
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He, Jing, Wang, Yuan, Qian, Yong, Guo, Jianshuang, Lu, Jiaxin, and Yang, Weicheng
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ULTRAHIGH molecular weight polyethylene , *CHEMICAL stability , *ABRASION resistance , *COMPOSITE materials , *SURFACE properties - Abstract
Ultra-high-molecular-weight polyethylene (UHMWPE) is often considered an ideal reinforcing material due to its extraordinary characteristics like high abrasion resistance, excellent toughness, and chemical stability. However, the poor surface properties have significantly hindered the progress of UHMWPE with high performance. This review is intended to introduce the physicochemical mechanisms of UHMWPE interfacial property modification. Therefore, this review provides a concise overview of the progress in diverse surface modification techniques for UHMWPE and their strengths and limitations as polymer reinforcement materials. Lastly, an overview of the potential and challenges of each surface modification has been summarized. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Investigation of high‐strain rate behavior of shear thickening fluid encapsulated electrospun ultra‐high molecular weight polyethylene/high‐density polyethylene fiber composites by split‐Hopkinson pressure bar.
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Nayak, Prajesh, Ghosh, Anup K., and Bhatnagar, Naresh
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POLYETHYLENE fibers ,MOLECULAR weights ,FLUID pressure ,FIBROUS composites ,POLYETHYLENE ,STRAIN rate ,WRINKLE patterns - Abstract
This study examines the high‐strain rate behavior of shear thickening fluid (STF)‐encapsulated samples of an electrospun mat. It comprises sandwich layers of STF‐impregnated ultra‐high molecular weight polyethylene (UHMWPE)/high‐density polyethylene (HDPE) mat enclosed within high‐temperature stretched electrospun neat UHMWPE fabric. The UHMWPE/HDPE mat was chosen for STF impregnation due to its porosity and the texture of its fiber surface, which contains pores, pits, wrinkles, and grooves ranging in size from nano‐ to micron‐scale. This feature enhances the adhesion and absorption of STF into the fiber structure and onto the fiber surface. These STF‐contained and corresponding neat samples were tested using an in‐house‐designed split‐Hopkinson pressure bar. The deformation and fracture behavior of samples were also monitored simultaneously using a high‐speed camera. The results showed that at a higher strain rate, the peak stress and energy absorption of STF‐encapsulated samples were more elevated due to increased inter‐fiber friction, unlike neat samples, which show a declining trend in peak stress and energy absorption due to yarn slippage. Moreover, the deformation during impact in neat samples was higher than in the STF‐encapsulated samples. Highlights: Electrospun ultra‐high molecular weight polyethylene and its HDPE blended fibersInterconnected pores and pits facilitated shear thickening fluid (STF) impregnation.STF‐encapsulation improved peak stress and toughness at high‐strain rates. [ABSTRACT FROM AUTHOR]
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- 2024
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9. STUDI IDENTIFIKASI PASANGAN COMMERCIALLY PURE TITANIUM DAN UHMWPE UNTUK APLIKASI MATERIAL IMPLAN LUTUT
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Firman Maulana Rusdi and Arini Dwi Cahyani
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identification, cp – titanium ,uhmwpe ,human body skeleton ,astm d638 ,polyethylene ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Orthopedics is a science that studies the human body skeleton. This field of science helps patients who experience joint and skeletal problems. One of the problems faced is the need for body frame components to be replaced, for example the knees. This replacement requires a man-made component, namely an implant. Implants can be made from metal, polymer, and ceramic. The biomaterial implant identification process includes X-Ray Diffraction analysis, hardness and tensile testing. XRD testing of CP–Titanium and UHMWPE using the Rigaku XRD tool. CP–Titanium hardness testing uses Vickers micro hardness, while for UHMWPE uses Shore D. CP–Titanium tensile testing uses a universal test machine with JIS Z2201 standards. Another material, namely UHMWPE, is tested using the same equipment as the ASTM D638 standard. The XRD test results for CP - Titanium show peaks of 35.3˚, 38.6˚, 40.2˚, namely the hexagonal structure of the compound element α - Ti. Meanwhile, UHMWPE material shows peaks (110) at 21.66˚ and (200) at 24.16˚. The peak data is an orthorhombic crystal structure, which is characteristic of polyethylene. The CP – Titanium hardness test results show an average hardness of 360.47 VHN. The hardness value of UHMWPE shows an average hardness of 48.5 Shore D. CP - Titanium tensile testing shows a maximum stress value of 534.4 MPa and a maximum strain value of 0.022. The UHMWPE tensile test showed an average maximum stress value of 23.87 MPa and an average maximum strain value of 1.36. The data above shows that the materials tested are CP - Titanium and UHMWPE. Hardness data indicates that these CP – Titanium and polyethylene materials are too soft for applications requiring wear resistance.
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- 2024
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10. Finite Element Analysis of the Bearing Component of Total Ankle Replacement Implants during the Stance Phase of the Gait Cycle
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Timothy S. Jain, Mohammad Noori, Joseph J. Rencis, Amanda Anderson, Naudereh Noori, and Scott Hazelwood
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bioengineering ,total ankle replacement (TAR) ,bearing component ,UHMWPE ,finite element analysis ,von Mises stress ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Total ankle arthroplasty (TAA) is a motion-preserving treatment for end-stage ankle arthritis. An effective tool for analyzing these implants’ mechanical performance and longevity in silico is finite element analysis (FEA). An FEA in ABAQUS was used to statically analyze the mechanical behavior of the ultra-high-molecular-weight polyethylene (UHMWPE) bearing component at varying dorsiflexion/plantarflexion ankle angles and axial loading conditions during the stance phase of the gait cycle for a single cycle. The von Mises stress and contact pressure were examined on the articulating surface of the bearing component in two newly installed fixed-bearing TAA implants (Wright Medical INBONE II and Exactech Vantage). Six different FEA models of variable ankle compressive load levels and ankle angle positions, for the varying subphases of the stance phase of the gait cycle, were created. The components in these models were constrained to be conducive to the bone–implant interface, where implant loosening occurs. Our results showed that the von Mises stress and contact pressure distributions increased as the compressive load increased. The highest stress was noted at dorsiflexion angles > 15°, in areas where the UHMWPE liner was thinnest, at the edges of the talar and UHMWPE components, and during the terminal stance phase of the gait cycle. This static structural analysis highlighted these failure regions are susceptible to yielding and wear and indicated stress magnitudes that are in agreement (within 25%) with those in previous static structural TAA FEAs. The mechanical wear of the UHMWPE bearing component in TAA can lead to aseptic loosening and peri-implant cyst formation over time, requiring surgical revision. This study provides ankle replacement manufacturers and orthopedic surgeons with a better understanding of the stress response and contact pressure sustained by TAA implants, which is critical to optimizing implant longevity and improving patient care.
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- 2024
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11. Numerical analysis of debris cloud formation in UHMWPE wavy plates during hypervelocity impact.
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Önder, Asım
- Abstract
This paper presents and analyses the numerical results of hypervelocity impact against ultra-high molecular weight polyethylene (UHMWPE) plates with four different surface wave profiles. UHMWPE wavy plates (WP) are intended to be used in Whipple Shield bumper plate, which is of paramount importance for space vehicles against micrometeorite and orbital debris (MMOD) impact protection. Numerical work was carried out as a hybrid combination of smoothed particle hydrodynamics (SPH) and finite element modelling (FEM). Circular plates were subjected to hypervelocity impact of a spherical aluminium projectile travelling at 3000 m/s. The outcomes of the simulations were analysed in terms of debris cloud generation, projectile fragmentation, and impact energy dissipation performance of wavy plates, and compared with a conventional flat counterpart. Results of this study indicate that surface wave profile has a clear positive influence in terms of hypervelocity impact protection performance. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Static and dynamic behaviour of ultra high molecular weight poly-ethylene (UHMWPE) Tensylon® composite.
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Castres, Magali, El Malki Alaoui, Aboulghit, Caisso, Camille, Monloubou, Martin, and Arrigoni, Michel
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DIGITAL image correlation , *MOLECULAR weights , *STRAIN rate , *STRAINS & stresses (Mechanics) - Abstract
Nowadays, ultra high molecular weight polyethylene (UHMWPE), allows the combination of lightweight, high strength and is praised for the design of severely loaded structures. It has become a good option for lightweight armour solutions. It is therefore important to characterise its mechanical behaviour. Up to now, strain rate effects on mechanical behaviour have been poorly explored. In this work, this issue is tackled by studying the strain rate influence on the in-plane deformation, in shear and tension of the Tensylon® HSBD30A, a UHMWPE dedicated to ballistic and blast protection. Two laminates of Tensylon® of respective orientation [0 °/90°]20 and [±45°]20 were subjected to static and split Hopkinson tensile bar (SHTB) tests. A new mounting system was designed, and new specimen shapes were used to match the experimental setup configurations. Digital image correlation (DIC) was used to measure the in-plane strain. A significant strain-rate dependence on the material behaviour.is evidenced. Besides, results exhibit a higher strength for the [0°/90°]20 specimen than for the [±45°]20 one. Despite some limitations, the proposed setup and measurement methods allowed visualisation of strain rate effects on the stress-strain relationship for strain rates ranging from the quasi-static regime to the dynamic one (1500 s–1). [ABSTRACT FROM AUTHOR]
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- 2024
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13. Finite Element Analysis of the Bearing Component of Total Ankle Replacement Implants during the Stance Phase of the Gait Cycle.
- Author
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Jain, Timothy S., Noori, Mohammad, Rencis, Joseph J., Anderson, Amanda, Noori, Naudereh, and Hazelwood, Scott
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TOTAL ankle replacement ,ULTRAHIGH molecular weight polyethylene ,FINITE element method ,COMPRESSION loads ,ORTHOPEDISTS ,ANKLE - Abstract
Total ankle arthroplasty (TAA) is a motion-preserving treatment for end-stage ankle arthritis. An effective tool for analyzing these implants' mechanical performance and longevity in silico is finite element analysis (FEA). An FEA in ABAQUS was used to statically analyze the mechanical behavior of the ultra-high-molecular-weight polyethylene (UHMWPE) bearing component at varying dorsiflexion/plantarflexion ankle angles and axial loading conditions during the stance phase of the gait cycle for a single cycle. The von Mises stress and contact pressure were examined on the articulating surface of the bearing component in two newly installed fixed-bearing TAA implants (Wright Medical INBONE II and Exactech Vantage). Six different FEA models of variable ankle compressive load levels and ankle angle positions, for the varying subphases of the stance phase of the gait cycle, were created. The components in these models were constrained to be conducive to the bone–implant interface, where implant loosening occurs. Our results showed that the von Mises stress and contact pressure distributions increased as the compressive load increased. The highest stress was noted at dorsiflexion angles > 15°, in areas where the UHMWPE liner was thinnest, at the edges of the talar and UHMWPE components, and during the terminal stance phase of the gait cycle. This static structural analysis highlighted these failure regions are susceptible to yielding and wear and indicated stress magnitudes that are in agreement (within 25%) with those in previous static structural TAA FEAs. The mechanical wear of the UHMWPE bearing component in TAA can lead to aseptic loosening and peri-implant cyst formation over time, requiring surgical revision. This study provides ankle replacement manufacturers and orthopedic surgeons with a better understanding of the stress response and contact pressure sustained by TAA implants, which is critical to optimizing implant longevity and improving patient care. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
14. Structural Design and Performance of Cut-Resistant Fabrics with Concave–Convex Arrays.
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Jiang, Fei, Su, Ting, Fang, Leimei, Zhao, Kezheng, and Cong, Honglian
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ULTRAHIGH molecular weight polyethylene , *ABRASION resistance , *STRUCTURAL design , *SOCIAL security , *LEGAL education - Abstract
As the risk of social security increases, it is crucial to develop flexible protective materials that combine flexibility with high protective performance. Ultra-high-molecular-weight polyethylene (UHMWPE) was selected as the raw material, and four types of flat-knitting cut-resistant fabrics were ultimately designed and prepared from a three-dimensional longitudinal dimension and concave–convex array structure based on rib knitting. A series of experiments must be conducted on fabrics in order to study the law of protection performance of different structural fabrics. They were thus subjected to comprehensive evaluation and theoretical analysis of cut resistance. The results demonstrate that the four structural fabrics exhibited resilience in abrasion tests, withstanding over 100,000 cycles without failure. A weighting algorithm was employed to determine the comprehensive cutting resistance of the S1, S2, S3, and S4 structural fabrics, resulting in values of 1939.9 gf, 2298.6 gf, 2577.1 gf, and 2822.2 gf, respectively. Therefore, S1 reached class A4, which is sufficient to address a medium cut hazard. Similarly, S2, S3, and S4 reached class A5, which is adequate to address a high cut hazard. The obtained fitting equation, with uniform yarn fineness T as the dependent variable, demonstrates that the cut resistance improved as the concave–convex density level increased. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Intra-Articular Surgical Reconstruction of a Canine Cranial Cruciate Ligament Using an Ultra-High-Molecular-Weight Polyethylene Ligament: Case Report with Six-Month Clinical Outcome.
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Ödman, Sven, Martenne-Duplan, Antonin, Finck, Marlène, Crumière, Antonin, Goin, Bastien, Buttin, Philippe, Viguier, Eric, Cachon, Thibaut, and Julinder, Krister
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ANTERIOR cruciate ligament ,TREATMENT effectiveness ,ULTRAHIGH molecular weight polyethylene ,JOINT diseases ,HEALTH outcome assessment - Abstract
Simple Summary: Rupture of the cranial cruciate ligament (CrCL) is a common condition in dogs, causing instability of the stifle, pain, lameness, osteoarthritis, and meniscal tears. Common treatments consist of tibial osteotomies or extra-articular stabilization of the stifle according to the size and weight of the dog. The most marginal routine practice is intra-articular stabilization, which consists of replacing the ruptured CrCL with an organic graft or a synthetic implant. This case report describes the technique used for the intra-articular synthetic reconstruction of the CrCL under arthroscopic guidance in a dog. This report is supported by a six-month clinical outcome assessment consisting of orthopedic examinations and radiographs. The dog showed quick resumption to normal gait and standing posture with no worsening of osteoarthritis and synovial effusion or complications. Mild signs of stifle instability were observed with no impact on clinical outcome. This technique could be considered an alternative for the treatment of CrCL rupture in dogs, but it needs confirmation from additional clinical studies with more dogs. The intra-articular reconstruction of the cranial cruciate ligament (CrCL) by an organic graft or a synthetic implant allows the restoration of physiological stifle stability. This treatment is still marginal in routine practice. A Rottweiler presented an acute complete CrCL rupture treated using an ultra-high-molecular-weight polyethylene (UHMWPE) implant. The latter was positioned under arthroscopic guidance and fixed with interference screws through femoral and tibial bone tunnels. The dog was weight-bearing just after surgery and resumed normal standing posture and gait after one month, with mild signs of pain upon stifle manipulation. At three months postoperatively, minimal muscle atrophy and minimal craniocaudal translation were noted on the operated hindlimb, with no effects on the clinical outcome. The stifle was painless. At six months postoperatively, standing posture and gait were normal, muscle atrophy had decreased, the stifle was painless, and the craniocaudal translation was stable. On radiographs, congruent articular surfaces were observed without worsening of osteoarthrosis over the follow-up, as well as stable moderate joint effusion. Replacement of a ruptured CrCL with a UHMWPE ligament yielded good functional clinical outcome at six months postoperatively. This technique could be considered an alternative for the treatment of CrCL rupture in large dogs, but it needs confirmation from a prospective study with more dogs. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Effect of Zirconia and Graphene Nanoparticles Loading on Thermo-Mechanical Performance of Hybrid Polymer Nanocomposite
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Devendra Kumar Singh, Rajesh Kumar Verma, and Sanjay Mishra
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zirconia ,graphene ,nanocomposite ,uhmwpe ,polymer ,Mining engineering. Metallurgy ,TN1-997 ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
This study demonstrates the development of a unique hybrid thermoplastic composite using reduced Graphene oxide (rGO) content and Zirconia (ZrO2) nanoparticles into the Ultra-High Molecular Weight Polyethylene (UHMWPE) biomaterials for continuous loading conditions. Specimens with different loadings of rGO (0 to 1.5 wt.%) and ZrO2 (5 to 10 wt.%) were fabricated using liquid phase ultrasonication followed by the hot press moulding method. The samples were analyzed using Thermogravimetric Analysis (TGA), Impact (Izod) testing, and Dynamic Mechanical Analysis (DMA). The developed material feasibility was assessed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses. The findings revealed that the 1 wt.% rGO/5 wt.% ZrO2/UHMWPE sample improved the storage modulus by 66.15%, and the Impact absorbed energy by 11.33% compared to the pristine UHMWPE. The proposed nanocomposite could be endorsed for artificial joints, prostheses, and other Artificial Bio-Bearing (ABB) applications.
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- 2024
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17. A hybrid approach of NiP coating and STF impregnation of UHMWPE fabric for conductive soft body armor
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Anand Biradar, S. Arulvel, and Jayakrishna Kandasamy
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UHMWPE ,NiP ,Electroless ,STF ,Ballistic ,Inter-yarn friction ,Mining engineering. Metallurgy ,TN1-997 - Abstract
To enhance the ballistic impact performance and impart electrical conductivity into soft armor material made up of UHMWPE fabric, a novel hybrid technique has been devised and incorporated. Initially, the NiP layer was deposited on the UHMWPE fabric surface through the electroless process, subsequently, it was impregnated in the shear thickening fluid (STF) based on nano-silica (40 wt%). The morphology, functional groups, phase structure, thermal stability, breaking load, inter-yarn friction, electro-heating, and ballistic impact performance of the neat (UHM), STF impregnated (UHM-STF), NiP coated(UHM/NiP), and NiP coated STF impregnated (UHM/NiP-STF) fabrics are detailed. The NiP coating enhanced the ballistic impact performance, and thermal stability, and became electrically conductive compared to neat fabric. The ballistic impact test confirmed the enhancement in the energy absorption of UHM-STF (30.84%), UHM/NiP(18.37%), and UHM/NiP-STF(54.82%) compared to UHM. The hybrid technique (UHM/NiP-STF) exhibited higher inter-yarn friction (53.79%) and ballistic impact energy absorption (18.43%) compared to UHM-STF. The significant rise in the impact energy absorption of the UHM/NiP-STF can be ascribed to the synergetic effect of enhanced inter-yarn friction induced by the NiP-coated layer and the shear thickening behavior exhibited by STF. The NiP-coated and STF-impregnated fabrics present a promising prospect for the advancement of soft body armor materials with multifunctional ability.
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- 2024
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18. The effects of high strain-rate and temperature on tensile properties of UHMWPE composite laminates
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Alia Ruzanna Aziz, Haleimah Al Abdouli, Naresh Kakur, Henrique Ramos, Rafael Savioli, Zhongwei Guan, and Rafael Santiago
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UHMWPE ,tensile properties ,high strain-rate ,temperature ,Digital Image Correlation ,theoretical modelling ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
The high strain-rate and temperature properties of ultra-high molecular weight polyethylene (UHMWPE) composites are limitedly available in the public domain, primarily due to challenges in gripping the extremely strong material during testing. In this study, tensile tests were performed on UHMWPE laminates over a range of strain-rates from 4.00 × 10-4 to 2.45 × 102 s-1, and at different temperatures from -10 to 70 °C using an innovative interchangeable clamping system. The clamp was designed to overcome gripping issues while ensuring consistent boundary conditions across various testing devices. Digital Image Correlation (DIC) technique was employed to capture the displacement fields in situ. The results show that UHMWPE composites demonstrate strain-rate strengthening and temperature-induced softening effects. The strain-rate dependent models indicate a notable difference in strain-rate sensitivity, particularly with tensile strength exhibiting 87 % and 60 % higher sensitivity compared to the tensile modulus and failure strain, respectively. The Weibull statistical model indicates that the scale parameter increases by 17 % with the increase in strain-rate due to transition in failure response from ductile to brittle, which is observed through optical microscopy. In contrast, the scale parameter decreases by 58 % with the increase in temperature. Therefore, it is important to consider the effects of strain-rate and temperature on the mechanical properties for effectively utilizing this material to develop numerical models in various impact-protective applications.
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- 2025
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19. Porovnání kvality nejčastěji používaných nových UHMWPE artikulačních vložek náhrady kolenního kloubu.
- Author
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POKORNÝ, D., ŠLOUF, M., GAJDOŠOVÁ, V., ŠEDĚNKOVÁ, I., VYROUBALOVÁ, M., NĚMEC, K., and FULÍN, P.
- Subjects
ULTRAHIGH molecular weight polyethylene ,TOTAL knee replacement ,ARTIFICIAL joints ,ORTHOPEDIC surgery ,DIFFERENTIAL scanning calorimetry - Abstract
PURPOSE OF STUDY Total joint replacements (TJR) have become the cornerstone of modern orthopedic surgery. A great majority of TJR employs ultrahigh molecular weight polyethylene (UHMWPE) liners. TJR manufacturers use many different types of UHMWPE, which are modified by various combinations of crosslinking, thermal treatment, sterilization and/or addition of biocompatible stabilizers. The UHMWPE modifications are expected to improve the polymer’s resistance to oxidative degradation and wear (release of microparticles from the polymer surface). This manuscript provides an objective, non-commercial comparison of current UHMWPE formulations currently employed in total knee replacements. MATERIALS AND METHODS UHMWPE liners from 21 total knee replacements (TKR) were collected which represent the most implanted liners in the Czech Republic in the period 2020–2021. The UHMWPEs were characterized using several methods: infrared microspectroscopy (IR), non-instrumented and instrumented microindentation hardness testing (MH and MHI), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and solubility measurements. The above-listed methods yielded quite complete information about the structure and properties of each UHMWPE type, including its potential long-term oxidation resistance. RESULTS For each UHMWPE liner, IR yielded information about immediate oxidative degradation (in the form of oxidation index, OI), level of crosslinking (trans-vinylene index, VI) and crystallinity (CI). The MH and MHI testing gave information about the impact of structure changes on mechanical properties. The remaining methods (DSC, TGA, and solubility measurements) provided additional information regarding the structure changes and resistance to long-term oxidative degradation. Statistical evaluation showed significant differences among the samples as well as interesting correlations among the UHMWPE modifications, structural changes, and mechanical performance. DISCUSSION Surprisingly enough, UHMWPE materials from different manufacturers showed quite different properties, including the resistance against the long-term oxidative degradation, which is regarded as one of the main reasons of TJR failures. The most promising UHMWPE types were crosslinked materials with biocompatible stabilizers. CONCLUSIONS Current UHMWPE liners from different manufactures used in total knee replacements exhibit significantly different structure and properties. From the point of view of clinical practice, the traditional UHMWPE types, which contained residual radicals from irradiation and/or gamma sterilization, showed inferior resistance to oxidative degradation and should be avoided. The best properties were observed in modern UHMWPE types, which combined crosslinking, biocompatible stabilizers, and sterilization by ethylenoxide or gas plasma. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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20. Evolution of the cavity structure of HDPE/UHMWPE blends during cold stretching.
- Author
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Yun, Sun, Pan, Xuefeng, Zhang, Feng, and He, Xuelian
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NUCLEATING agents ,CAVITATION ,DISPERSION (Chemistry) - Abstract
The cavitation process of high‐performance HDPE/UHMWPE blends with a uniform dispersion of UHMWPE during cold stretching was investigated. It was observed that incorporating a small amount of UHMWPE into the HDPE matrix resin can serve as a nucleating agent, increasing the number of contact sites and accelerating the crystallization rate. This leads to the formation of thicker lamellar crystals and tethered molecules, ultimately enhancing the mechanical properties of the HDPE matrix. Furthermore, the relationship between the natural tensile ratio and strain‐hardening modulus was confirmed. Microstructural changes within the blends were also explored. As the drawing tangles in the middle, the cavities subsequently evolve by collapsing and merging to align parallel to the tensile direction, culminating in tensile damage forming a large crack in the final macroscopic form. As a result, the presence of more tethered molecules in the later stages of stretching inhibits further cavity growth. Highlights: The HDPE/UHMWPE blends were prepared by solution blending and ultrasound‐assisted twin‐screw extrusion.The mechanisms underlying the formation and evolution of cavities in HDPE/UHMWPE blends, which lead to stress whitening during tensile damage, were examined by using DSC and SAXS/WAXD.The relationship between microstructure and mechanical properties was analyzed by cold‐drawing the molded blended sheets at room temperature. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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21. Vitamin E‐stabilized polyethylene shows similar survival rates at minimum 7‐year follow‐up compared to conventional polyethylene in primary total knee arthroplasty.
- Author
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Bistolfi, Alessandro, Spezia, Marco, Cipolla, Alessandra, Bonera, Monica, Mellano, Danilo, Banci, Lorenzo, Colombo, Marta, and Massè, Alessandro
- Subjects
ULTRAHIGH molecular weight polyethylene ,TOTAL knee replacement ,VITAMIN E ,ASYMPTOMATIC patients ,SURVIVAL rate - Abstract
Purpose: The aim of this cross‐sectional study was to compare survival, clinical and radiographic results of total knee arthroplasty (TKA) with vitamin E‐stabilized polyethylene (VEPE) or conventional polyethylene (CPE) at a minimum of 7‐year follow‐up. Methods: Patients who underwent primary TKA between 2011 and 2015, receiving the same cemented rotating platform knee design with VEPE or CPE tibial inserts, were identified. Patients were contacted for clinical and radiographic follow‐up. American Knee Society Score (KSS), Forgotten Joint Score (FJS‐12), presence of periprosthetic radiolucent lines (RLLs) and osteolysis were evaluated at the last follow‐up. Any revision, reintervention or other complications were recorded. Results: Among 350 TKAs initially identified, 102 VEPE and 97 CPE knees were included for analysis with mean follow‐up of 8.5 and 8.3 years, respectively. No significant difference was found in survival rates at 10‐year follow‐up with revision due to aseptic loosening (95.0% vs. 97.8%, p = 0.29) or due to any reason (87.6% vs. 89.6%, p = 0.78) between VEPE and CPE TKA. KSS function score resulted significantly higher in the VEPE group over CPE (77 vs. 63, p = 0.01). RLLs were more frequent in VEPE than CPE (54% vs. 32%, p = 0.05), mainly noticed medially and posteriorly beneath the tibial plate, adjacent to the trochlear shield and the posterior condyles. Osteolysis was observed in one knee per group, but patients were asymptomatic with stable implants. Conclusion: TKA with VEPE and CPE tibial inserts showed comparable survival rates, complications and clinical and radiographic results up to 10‐year follow‐up. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Finite Element Simulation of Dry Wear of Prosthesis Made of UHMWPE and 316LVM Stainless Steel.
- Author
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de la Mora Ramírez, Tomas, López, Elías Crispín, Onofre, Daniel Maldonado, Moreno, Elvis Coutiño, Perrusquia, Noé López, Ruíz, Marco A. Doñu, and San Miguel, Christhopher René Torres
- Subjects
MATERIAL plasticity ,APPLIED mechanics ,STAINLESS steel ,FINITE element method ,MECHANICAL wear - Abstract
The study of wear is currently one of the most important aspects of applied mechanics. The damage caused by this phenomenon involves the total replacement of parts in devices ranging from industrial machinery to biomedical implants. The focus of these work is aimed at the analysis and prediction of mechanical wear in prostheses manufactured using UHMWPE materials and 316 LVM stainless steel by means of the finite element method using Abaqus
® software V. 2020. The wear mechanism between the surfaces of the UHMWPE material specimen and a 316 LVM stainless steel specimen was modeled using Archard's wear theory to determine the parameters of damage, plastic deformation, and fatigue. The attrition process was discretized into several steps, including developing a program in Fortran code, and integrating a pre-established subroutine known as UMESHMOTION, followed by a Mesh update whenever contact nodes were deformed. For the simulation process, the variables of the thermal properties of conductivity, specific heat, and the parameters of the Johnson-Cook plastic model were taken into account. The simulation results were validated by laboratory tests. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
23. Feasibility of Repairing Concrete with Ultra-High Molecular Weight Polyethylene Fiber Cloth: A Comprehensive Literature Review.
- Author
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Pan, Zengrui, Tuladhar, Rabin, Yin, Shi, Shi, Feng, and Dang, Faning
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LITERATURE reviews ,POLYETHYLENE fibers ,MOLECULAR weights ,FIBER-reinforced plastics ,HIGH density polyethylene ,CONCRETE - Abstract
This review explores the use of Ultra-High Molecular Weight Polyethylene (UHMWPE) fiber cloth as an innovative solution for the repair and reinforcement of concrete structures. UHMWPE is a polymer formed from a very large number of repeated ethylene (C
2 H4 ) units with higher molecular weight and long-chain crystallization than normal high-density polyethylene. With its superior tensile strength, elongation, and energy absorption capabilities, UHMWPE emerges as a promising alternative to traditional reinforcement materials like glass and carbon fibers. The paper reviews existing literature on fiber-reinforced polymer (FRP) applications in concrete repair in general, highlighting the unique benefits and potential of UHMWPE fiber cloth compared to other commonly used methods of strengthening concrete structures, such as enlarging concrete sections, near-surface embedded reinforcement, and externally bonded steel plate or other FRPs. Despite the scarcity of experimental data on UHMWPE for concrete repair, this review underscores its feasibility and calls for further research to fully harness its capabilities in civil engineering applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
24. Temperature and strain rate effects on ultra‐high‐molecular‐weight‐polyethylene compression: An experimental and modeling approach.
- Author
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Kumar, Manohar, Ravi, Kesavan, and Singh, Sarthak S.
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STRAIN rate ,STRESS-strain curves ,VISCOPLASTICITY ,CRYSTAL structure ,MECHANICAL models ,COMMERCIAL real estate - Abstract
This study aims to predict the compression behavior of ultra‐high molecular weight polyethylene (UHMWPE) at various temperatures (25, 40, and 55°C) and strain rates (~10−4/s and ~10−2/s) using a single set of three‐network (TN) viscoplastic model parameters. The TN model is made up of three parallel networks: networks A and B use nonlinear springs and dashpots to control the responses of the crystalline phase and confined amorphous phases, respectively, while network C captures the macromolecular amorphous networks using a single nonlinear spring. A single set of TN model parameters captures the yield and post‐yield hardening responses of the stress–strain curves at experimental temperatures and strain rates. When these TN model calibrated parameters are used as material property in a commercial finite element tool to simulate UHMWPE compression, the predicted and simulated results match well, showing the model's fidelity. Additionally, the model predicts experiments conducted at 40 and 70°C with loading rates of ~10−3/s and ~10−2/s, respectively. The study also correlates the deformations of UHMWPE's crystalline structure and macromolecular amorphous networks with its global stress versus strain response by extracting stresses from individual networks of the TN model at different strain rates and temperatures. Highlights: UHMWPE's mechanical behavior predicted by a single set of TN model parametersTN model predicts mechanical response at various strain rates and temperatures.TN model explains microstructural crystalline and amorphous phase deformations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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25. Effect of Nitrate Acid Treated Dolomite on the Tensile Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) Composites
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S.F.A. Abdullah, S.S. Md Saleh, N.F Mohammad, S.N. Syed Mahamud, M.F. Omar, H.Md Akil, B.P Chang, H.R Saliu, N.H. Rostam, and J. Gondro
- Subjects
uhmwpe ,chemical treatments of bamboo ,dolomite ,polymer composites ,biomedical ,Mining engineering. Metallurgy ,TN1-997 ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Ultra-High Molecular Weight Polyethylene (UHMWPE) polymers have been used in biomedical applications due to its biocompatibility, durability, toughness and high wear resistance. To enhance the mechanical properties, various types of minerals are commonly utilized as fillers in UHMWPE. One of the minerals is dolomite, which has been recognized as a valuable mineral with versatile applications, particularly in the field of biomedical applications. This paper presents the tensile properties of UHMWPE composites that filled with dolomite and treated-dolomite at various filler loading (i.e., 1-5 wt.%). Nitric acid and diammonium phosphate were used to treat the dolomite. From the results, the peaks of the FTIR spectrum displays carbonate (CO3–2), phosphate (PO4–3) and hydroxyl (OH–) groups in the ct-dolomite powder sample while the XRD pattern reveals that using dolomite treated with 1M nitric acid resulted in the presence of calcium hydroxide phosphate (Ca10(PO4)5(OH)) and MgO. For tensile strength, UHMWPE/ct-dolomite composites show better tensile strength than the pure UHMWPE composites. Treated improve the dolomite filler and resulted in significantly better matrix-filler interfacial interactions and improve the properties.
- Published
- 2024
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26. Ultra-high molecular weight polyethylene synthesis using externally modified Si-Mg-Ti based Z-N catalyst system
- Author
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Hiren Bhajiwala and Virendrakumar Gupta
- Subjects
si-mg-ti ziegler-natta catalyst ,uhmwpe ,ethylene polymerization ,external donor ,Polymers and polymer manufacture ,TP1080-1185 - Abstract
Ultra-high molecular weight polyethylene (UHMWPE) was synthesized using Bi-supported SiO2/MgCl2/TiCl4 (Si-Mg-Ti) Ziegler-Natta catalyst in conjugation with triethyl aluminum (TEA). The impact of temperature and the presence of a chain-terminating agent were examined in the context of ethylene polymerization. The findings showed that as temperature decreases, the activity of the polymerization decreases, and the molecular weight of the polymer increases. Conversely, in the presence of a chain-terminating agent, the molecular weight of the polymer decreases. The introduction of Triethyl borate (TEB) and Tetraethoxy silane (TEOS) as an external donor has a pronounced effect on the catalyst activity, causing a significant decrease, while simultaneously leading to a substantial increase in the viscosity average molecular weight (Mv). Additionally, when a chain-terminating agent is added along with Triethyl borate (TEB) in the system, it results in a significant decrease in molecular weight, albeit with a slight increase in activity compared to a system without a donor. The crystallinity, particle size and bulk density of the polymer synthesized with and without external donor also investigated.
- Published
- 2024
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- View/download PDF
27. Molecular Dynamics Simulation of Mechanical and Tribological Properties of Ultrahigh Molecular Weight Polyethylene Enhanced by Modified Silica Nanoparticles
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Zhou, Xincong, Li, Binbin, Huang, Qipeng, and Huang, Jian
- Published
- 2024
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28. Impact of natural antioxidant (silybin) on the thermal stability of ultra high molecular weight polyethylene: a thermogravimetric study
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Khattar, Nidhi, Jagriti, Kainth, Shagun, Sharma, Piyush, Ahlawat, Vishal, Berar, Urmila, and Diwan, Pawan K.
- Published
- 2024
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29. Vitamin E-enriched medium cross-linked polyethylene in total knee arthroplasty (VIKEP): clinical outcome, oxidation profile, and wear analysis in comparison to standard polyethylene—study protocol for a randomized controlled trial
- Author
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Maier, Kristin, Selig, Marius, Haddouche, Andréa, Haunschild, Martin, Hauschild, Oliver, Khalili, Iman, Kirschberg, Julia, Lutter, Christoph, Menges, Michael, Mertl, Patrice, Niemeier, Andreas, Rubens-Duval, Brice, and Mittelmeier, Wolfram
- Published
- 2024
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- View/download PDF
30. EFFECT OF ZIRCONIA AND GRAPHENE NANOPARTICLES LOADING ON THERMO-MECHANICAL PERFORMANCE OF HYBRID POLYMER NANOCOMPOSITE.
- Author
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SINGH, DEVENDRA KUMAR, VERMA, RAJESH KUMAR, and MISHRA, SANJAY
- Subjects
THERMOPLASTIC composites ,NANOPARTICLES ,NANOCOMPOSITE materials ,ARTIFICIAL joints ,GRAPHENE oxide ,ZIRCONIUM oxide - Abstract
This study demonstrates the development of a unique hybrid thermoplastic composite using reduced Graphene oxide (rGO) content and Zirconia (ZrO2) nanoparticles into the Ultra-High Molecular Weight Polyethylene (UHMWPE) biomaterials for continuous loading conditions. Specimens with different loadings of rGO (0 to 1.5 wt.%) and ZrO2 (5 to 10 wt.%) were fabricated using liquid phase ultrasonication followed by the hot press moulding method. The samples were analyzed using Thermogravimetric Analysis (TGA), Impact (Izod) testing, and Dynamic Mechanical Analysis (DMA). The developed material feasibility was assessed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses. The findings revealed that the 1 wt.% rGO/5 wt.% ZrO2/UHMWPE sample improved the storage modulus by 66.15%, and the Impact absorbed energy by 11.33% compared to the pristine UHMWPE. The proposed nanocomposite could be endorsed for artificial joints, prostheses, and other Artificial Bio-Bearing (ABB) applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Titanium Nitride Coatings on CoCrMo and Ti6Al4V Alloys: Effects on Wear and Ion Release.
- Author
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AbuAlia, Mohammed, Fullam, Spencer, Cinotti, Filippo, Manninen, Noora, and Wimmer, Markus A.
- Subjects
TITANIUM nitride ,ALLOYS ,ULTRAHIGH molecular weight polyethylene ,SURFACE coatings ,ORTHOPEDIC implants ,MECHANICAL abrasion ,MAGNETRON sputtering - Abstract
While titanium nitride (TiN) coatings are well known for their biocompatibility and excellent mechanical properties, their wear particle and debris release in orthopedic implants remains a matter of active investigation. This study addresses the efficacy of TiN coatings on CoCrMo and Ti6Al4V alloys to enhance wear resistance and reduce ion release from prosthetic implants. Three different coating variants were utilized: one variant deposited using arc evaporation (Arc) followed by post-treatment, and two variants deposited using high-power impulse magnetron sputtering (HiPIMS) with or without post-treatment. The coatings' performance was assessed through standard wear testing against ultra-high-molecular-weight polyethylene (UHMWPE) in bovine serum lubricant, and in the presence of abrasive PMMA bone cement particles in the lubricant. The results indicated that Arc and HiPIMS with post-treatment significantly reduced wear and eliminated detectable metal ion release, suggesting that these coatings could extend implant longevity and minimize adverse biological responses. Further long-term simulator and in vivo studies are recommended to validate these promising findings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. The Development and Performance of Knitted Cool Fabric Based on Ultra-High Molecular Weight Polyethylene.
- Author
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Zhao, Yajie, Dong, Zhijia, He, Haijun, and Cong, Honglian
- Subjects
- *
MOLECULAR weights , *THERMAL conductivity , *TEXTILES , *YARN , *STATISTICAL correlation , *POLYETHYLENE , *DRYING agents - Abstract
In order to withstand high-temperature environments, ultra-high molecular weight polyethylene (UHMWPE) fibers with cooling properties are being increasingly used in personal thermal management textiles during the summer. However, there is relatively little research on its combination with knitting. In this paper, we combine UHMWPE fiber and knitting structure to investigate the impact of varying UHMWPE fiber content and different knitting structures on the heat and humidity comfort as well as the cooling properties of fabrics. For this purpose, five kinds of different proportions of UHMWPE and polyamide yarn preparation, as well as five kinds of knitted tissue structures based on woven tissue were designed to weave 25 knitted fabrics. The air permeability, moisture permeability, moisture absorption and humidity conduction, thermal property, and contact cool feeling property of the fabrics were tested. Then, orthogonal analysis and correlation analysis were used to statistically evaluate the properties of the fabrics statistically. The results show that as the UHMWPE content increases, the air permeability, heat conductivity, and contact cool feeling property of the fabrics improve. The moisture permeability, moisture absorption and humidity conductivity of fabrics containing UHMWPE are superior to those containing only polyamide. The air permeability, moisture permeability, and thermal conductivity of the fabrics formed by the tuck plating organization are superior to those of the flat needle plating and float wire plating organization. The fabric formed by 2 separate 2 float wire organization has the best moisture absorption, humidity conduction, contact cool feeling property. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Classification of Progressive Wear on a Multi-Directional Pin-on-Disc Tribometer Simulating Conditions in Human Joints-UHMWPE against CoCrMo Using Acoustic Emission and Machine Learning.
- Author
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Deshpande, Pushkar, Wasmer, Kilian, Imwinkelried, Thomas, Heuberger, Roman, Dreyer, Michael, Weisse, Bernhard, Crockett, Rowena, and Pandiyan, Vigneashwara
- Subjects
ACOUSTIC emission ,CONVOLUTIONAL neural networks ,MACHINE learning ,ULTRAHIGH molecular weight polyethylene ,JOINTS (Anatomy) ,PROSTHETICS - Abstract
Human joint prostheses experience wear failure due to the complex interactions between Ultra-High-Molecular-Weight Polyethylene (UHMWPE) and Cobalt-Chromium-Molybdenum (CoCrMo). This study uses the wear classification to investigate the gradual and progressive abrasive wear mechanisms in UHMWPE. Pin-on-disc tests were conducted under simulated in vivo conditions, monitoring wear using Acoustic Emission (AE). Two Machine Learning (ML) frameworks were employed for wear classification: manual feature extraction with ML classifiers and a contrastive learning-based Convolutional Neural Network (CNN) with ML classifiers. The CNN-based feature extraction approach achieved superior classification performance (94% to 96%) compared to manual feature extraction (81% to 89%). The ML techniques enable accurate wear classification, aiding in understanding surface states and early failure detection. Real-time monitoring using AE sensors shows promise for interventions and improving prosthetic joint design. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Understanding the pore structure evolution of polyethylene separator with dissipative particle dynamics simulation.
- Author
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Wang, Hao, Wu, Zonglin, Lu, Yue, Zhang, Hang, Cheng, Guang, Liu, Gaojun, and Bai, Yaozong
- Subjects
PARTICLE dynamics ,POROSITY ,POLYETHYLENE ,MOLECULAR weights ,PARAFFIN wax - Abstract
The commercialized lithium‐ion battery separators are mass‐produced by mixing ultra‐high molecular weight polyethylene (UHMWPE) and paraffin oil (PO). The dissipative particle dynamics method is utilized to investigate the extrinsic factors (shear rate and cooling rate) and the intrinsic factors (the molecular chain length) on the microstructure of the UHMWPE‐PO mixture. For the mixture with UHMWPE possessing the same chain length, the high shear rate promoted a lower porosity (~28%) and smaller pores. In contrast, the slow shearing led to a high porosity (~40%) and larger pores. For the mixture with UHMWPE possessing short and long chains, the shear rate hardly affects the porosity and the pore size: the porosity was kept at ~30%, and the pore size was reduced by ~35% compared to the model with the same‐chain‐length UHMWPE. The cooling rate after shearing is the dominant factor in determining the porosity and pore size: the fast cooling raised the porosity by ~33% but hardly increased the pore size, while the slow cooling raised the porosity by ~74%, and the pore size by ~105%. The current study provided a deep understanding of the pore structure evolution in separator processing. Highlights: The effects of processing parameters on the pore structures are numerically illustrated.MD simulation and rheometer measurement assist DPD interaction parameters calibration for UHMWPE and PO.The low shear rate leads to a higher porosity and pore size.At the high shear rate, short UHMWPE chains reduce porosity but do not increase pore size.The fast‐cooling process slightly increases the porosity while keeping the pore size. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Ultra-high molecular weight polyethylene synthesis using externally modified Si-Mg-Ti Based Z-N catalyst system.
- Author
-
Bhajiwala, Hiren and Gupta, Virendrakumar
- Subjects
MOLECULAR weights ,ZIEGLER-Natta catalysts ,POLYETHYLENE ,POLYMERS - Abstract
Ultra-high molecular weight polyethylene (UHMWPE) was synthesized using Bi-supported SiO2 /MgCl2 /TiCl4 (Si-Mg-Ti) Ziegler-Natta catalyst in conjugation with triethyl aluminum (TEA). The impact of temperature and the presence of a chain-terminating agent were examined in the context of ethylene polymerization. The findings showed that as temperature decreases, the activity of the polymerization decreases, and the molecular weight of the polymer increases. Conversely, in the presence of a chain-terminating agent, the molecular weight of the polymer decreases. The introduction of triethyl borate (TEB) and tetraethoxy silane (TEOS) as an external donor has a pronounced effect on the catalyst activity, causing a significant decrease, while simultaneously leading to a substantial increase in the viscosity average molecular weight (Mv ). Additionally, when a chain-terminating agent is added along with triethyl borate (TEB) in the system, it results in a significant decrease in molecular weight, albeit with a slight increase in activity compared to a system without a donor. The crystallinity, particle size and bulk density of the polymer synthesized with and without external donor have been also investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Numerical modelling of the ballistic impact response of hybrid composite structures
- Author
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L. Peng, J. Zhou, Q.Y. Wang, X.F. Zhang, and Z.W. Guan
- Subjects
Finite element ,Ballistic performance ,Hybrid laminates ,Ceramic ,UHMWPE ,Compressed wood ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
This paper presents numerical modelling of the ballistic impact response of hybrid laminated structures, which are developed through combinations of ceramics, Ultra-High-Molecular-Weight Polyethylene (UHMWPE), Kevlar and compressed wood. It is, for the first time, to embed the compressed wood in the ballistic panel and numerically investigate the impact response of the hybrid structures made of the multiple constituent materials. Different constitutive models and the related failure criteria were employed in the modelling to capture the ballistic responses of the constituent materials and hybrid structures. The numerical simulations were compared with the corresponding experimental results with acceptable correlation. The essential features of the hybrid composite structures subjected to high velocity impact were simulated by the finite element (FE) models, such as deformation and failure modes, back-face signature and the residual velocities. The FE models developed are ready to be used to assist design lightweight composite armour with optimized ballistic resistance and self-weight.
- Published
- 2024
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- View/download PDF
37. Vitamin E‐stabilized polyethylene shows similar survival rates at minimum 7‐year follow‐up compared to conventional polyethylene in primary total knee arthroplasty
- Author
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Alessandro Bistolfi, Marco Spezia, Alessandra Cipolla, Monica Bonera, Danilo Mellano, Lorenzo Banci, Marta Colombo, and Alessandro Massè
- Subjects
conventional polyethylene ,total knee arthroplasty ,UHMWPE ,vitamin E ,vitamin E‐stabilized ,Orthopedic surgery ,RD701-811 - Abstract
Abstract Purpose The aim of this cross‐sectional study was to compare survival, clinical and radiographic results of total knee arthroplasty (TKA) with vitamin E‐stabilized polyethylene (VEPE) or conventional polyethylene (CPE) at a minimum of 7‐year follow‐up. Methods Patients who underwent primary TKA between 2011 and 2015, receiving the same cemented rotating platform knee design with VEPE or CPE tibial inserts, were identified. Patients were contacted for clinical and radiographic follow‐up. American Knee Society Score (KSS), Forgotten Joint Score (FJS‐12), presence of periprosthetic radiolucent lines (RLLs) and osteolysis were evaluated at the last follow‐up. Any revision, reintervention or other complications were recorded. Results Among 350 TKAs initially identified, 102 VEPE and 97 CPE knees were included for analysis with mean follow‐up of 8.5 and 8.3 years, respectively. No significant difference was found in survival rates at 10‐year follow‐up with revision due to aseptic loosening (95.0% vs. 97.8%, p = 0.29) or due to any reason (87.6% vs. 89.6%, p = 0.78) between VEPE and CPE TKA. KSS function score resulted significantly higher in the VEPE group over CPE (77 vs. 63, p = 0.01). RLLs were more frequent in VEPE than CPE (54% vs. 32%, p = 0.05), mainly noticed medially and posteriorly beneath the tibial plate, adjacent to the trochlear shield and the posterior condyles. Osteolysis was observed in one knee per group, but patients were asymptomatic with stable implants. Conclusion TKA with VEPE and CPE tibial inserts showed comparable survival rates, complications and clinical and radiographic results up to 10‐year follow‐up. Level of Evidence Level III.
- Published
- 2024
- Full Text
- View/download PDF
38. Characterization of surface and bulk properties of α-Tocopherol blended and γ irradiated UHMWPE sandwich nanocomposites
- Author
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Sri Ram Murthy Paladugu, Santosh Kumar Sahu, Sivanagaraju Namathoti, Ketul C. Popat, Ragavanantham Shanmugam, and P.S. Rama Sreekanth
- Subjects
UHMWPE ,Graphene ,Nano-diamond ,Vitamin-E ,Gamma irradiation ,Sandwich composite ,Technology - Abstract
In the present study, an unconventional approach in compression molding is chosen to fabricate Ultra High Molecular Weight Polyethylene (UHMWPE) sandwich composites with Graphene (Gr) and Nano-diamond (ND) as fillers. A unique comparison is done between the surface and bulk properties of UHMWPE nano-composites and UHMWPE sandwich composites. Influence of gamma irradiation at doses of 50, 100 kGy doses and vitamin E (vit-E) on crystal structure, mechanical, thermal and tribological characteristics of UHMWPE composites were studied through x-ray diffraction (XRD), raman spectroscopy, dynamic mechanical analysis (DMA), rheology, differential scanning calorimetry (DSC), tensile, nano-indentation and wear characterization techniques. Fracture regions and surface wear of the samples were analysed through scanning electron microscopy (SEM) to understand the dispersion behavior of fillers in matrix. The concentration of vit-E content in UHMWPE greatly influenced the crosslinks and surface properties in gamma irradiated composites. Gamma irradiation have shown significant improvement in crystallinity, viscous behavior and bulk properties of UHMWPE composites. Irradiated UHMWPE nano-composites have shown better tensile results when compared with sandwich composites, with 22 % increase in young's modulus and 16 % increase in yield stress. Wear rate has been reduced by 25 % for irradiated sandwich UHMWPE composites when compared with UHMWPE nano-composites.
- Published
- 2024
- Full Text
- View/download PDF
39. Plasma surface modification of UHMWPE fibres and its effects on adhesion and wettability
- Author
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Sikander, Usman, Wisnom, Michael, and Hamerton, Ian
- Subjects
interfaces ,Adhesion ,Wetting ,UHMWPE ,Plasma treatment - Abstract
Ultra-High Molecular Weight Polyethylene (UHMWPE) fibres are gel-spun, highly drawn polymeric fibres that offer excellent strength and modulus, chemical resistance, and impact resistance with low density. However, due to their non-polar surface character, polymer matrix composites employing these fibres have a low interfacial shear strength (IFSS), leading to a low interlaminar shear strength (ILSS). This project aims to study the surface modification of UHMWPE fibres at micro and molecular levels for improved wettability and adhesion with thermosetting matrices using a plasma treatment (reactive ion etching) route. In this study, an in-depth characterization was conducted on UHMWPE fibres and tapes in an untreated and plasma-treated state and the effects of plasma treatment were compared. Surface modification of samples was done using the reactive ion etching (RIE) process, where Ar-O₂ plasma (1:5 standard cubic centimetres per minute) was used at 30, 50 and 100 W RF power. Samples were exposed to plasma for 10, 15, 20, 30, 60 and 300 seconds. FTIR results confirmed the presence of various oxygen-bearing functional groups such as -C=O at 2320-2220 cm⁻¹, -C=O carbonyl stretches of ketones, esters, and aldehydes at 1780-1700 cm⁻¹, and -C=C- at 1620-1520 cm⁻¹ due to chain scission of main carbon C-C bonds. XPS confirmed an increase in atomic oxygen content because of plasma treatment. Wettability is determined by the interaction between the fibres and the resin. Untreated fibres and tapes showed mildly hydrophobic character with a water contact angle (WCA) of 93.3 ± 3.3°. Plasma treatment increased surface free energy (γSV) from 36.4 ± 3.4 mN m⁻¹ to 71.1 ± 2.8 mN m⁻¹, and decreased water contact angle (WCA) to 35.3 ± 4.7°, indicating improvements in wettability of the fibres. Specifically, the polarity (γSVᴾ) of the surface increased from 0.4 ± 0.0 mN m⁻¹ to 21.3 ± 2.2 mN m⁻¹, which proved beneficial for improved adhesion of these fibres with the epoxy matrix. Due to hydrophobic recovery, γSV and γSVᴾ decreased by 30% and 40%, respectively, within the first 24 hours and up to 40% and 59% within seven days of plasma treatment. The solid-liquid (interfacial) tension (γSL) decreased while the work of adhesion (Wa), spreading coefficient (S) and wetting tension (ΔF) increased after plasma treatment, indicating favourable wetting conditions. The interfacial adhesion between UHMWPE and epoxy increased from 2.2 ± 0.4 MPa to 5.1 ± 1.1 MPa, when samples were exposed to plasma for 10 seconds. A longer exposure time of 60 and 300 seconds lead to an increase in IFSS to 5.7 ± 1.0 and 5.9 ± 0.5 MPa, respectively. The variation in IFSS (휏퐼퐹푆푆) was found to be independent of surface roughness, indicating that the mechanical interlocking was not the sole reason for increased IFSS. Similarly, the interfacial frictional stress (휏푓) in the post-debonded region of the microbond curve was independent of surface roughness and remained nearly constant (휏푓 = 1.3 ± 0.6 MPa) for untreated and all plasma-treated samples. Droplets cured on single fibres with different cure schedules were observed to have mean values significantly different from each other, suggesting the influence of processing parameters on measured IFSS. The micro composite samples cured at 50, 65 and 80 °C were shown to influence the 휏퐼퐹푆푆 significantly. Novel composite laminates with UHMWPE interlayers were produced and tested in three-point (short-beam) bend tests to determine ILSS. Carbon/epoxy laminates (L1) showed an ILSS of 88.1 ± 4.1 MPa, and those with untreated UHMWPE interlayer (L2) showed a decreased ILSS of 26.0 ± 4.5 MPa. However, with plasma treatment, the ILSS of the carbon/UHMWPE/epoxy laminates (L3) increased to 42.3 ± 6.2 MPa, suggesting improved interaction between the Dyneema® and adjoining carbon/epoxy layers. Plasma treatment was shown to change the failure mechanism of Dyneema®, i.e., the untreated samples showed a clean fracture. In contrast, the plasma-treated samples showed defibrillation of the Dyneema® tape, indicating improved adhesion. Overall, this work has furthered the knowledge of how plasma modifies UHMWPE fibre's surface and improves its adhesion and wetting properties with epoxy matrix by increasing γSV and specifically γSVᴾ. However, this improvement was limited, and the level of adhesion achieved was significantly less than that achievable for the carbon/epoxy or glass/epoxy system. Compatibility between UHMWPE and UV curable resins was explored. With further development in processing these resins at low temperatures, the use of UHMWPE in various sectors can be exploited.
- Published
- 2022
40. The influence of lubricant temperature on the wear of total knee replacements
- Author
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Raelene M. Cowie, Adam Briscoe, and Louise M. Jennings
- Subjects
biotribology ,PEEK ,total knee replacement ,UHMWPE ,wear ,Biotechnology ,TP248.13-248.65 ,Biochemistry ,QD415-436 - Abstract
Abstract Experimental in vitro simulation can be used to predict the wear performance of total knee replacements. The in vitro simulation should aim to replicate the in vivo loading, motion and environment experienced by the joint, predicting wear and potential failure whilst minimising test artefacts. Experimental wear simulation can be sensitive to environmental conditions; the environment temperature is one variable which should be controlled and was the focus of this investigation. In this study, the wear of an all‐polymer (PEEK‐OPTIMA™ polymer‐on‐UHMWPE) total knee replacement and a conventional cobalt chrome‐on‐UHMWPE implant of similar initial surface topography and geometry were investigated under elevated temperature conditions. The wear was compared to a previous study of the same implants under simulator running temperature (i.e. without heating the test environment). Under elevated temperature conditions, the wear rate of the UHMWPE tibial inserts was low against both femoral component materials (mean
- Published
- 2023
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- View/download PDF
41. Hugely improved electromagnetic interference shielding and mechanical properties for UHMWPE composites via constructing an oriented conductive carbon nanostructures (CNS) networks
- Author
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Huibin Cheng, Longshan Bai, Guoliang Lin, Xiaoyi Zhang, Chen Wu, Shenglan Ma, Xuhong Liu, Baoquan Huang, Qinghua Chen, Qingrong Qian, and Changlin Cao
- Subjects
UHMWPE ,Carbon nanostructures (CNS) ,Electromagnetic interference ,Electrical properties ,Thermal conductivity ,Mining engineering. Metallurgy ,TN1-997 - Abstract
To address the practical application challenges of conductive polymer composites (CPCs) in portable electronics equipment, such as their low thermal conductivity (TC) and poor electromagnetic interference (EMI) shielding effectiveness (EMI SE), it is crucial to improve their TC, electrical conductivity(σ), and EMI SE of CPCs. In this work, we present a conducting composite made of ultrahigh molecular weight polyethylene (UHMWPE) and carbon nanostructures (CNS) with a unique segregated structure. This structure is achieved through a simple high-speed mechanical mixing and compression molding process. Microscopy characteristics demonstrated that both the matrix and segregated conductive network were in-situ oriented along the compress direction of UHMWPE granules under the static hot-pressing field. CNS are compacted together at the interface between UHMWPE granules to form an oriented and interconnected conductive pathways at low CNS loading levels. The resultant UHMWPE/CNS composites with 10 wt% CNS content exhibits excellent EMI shielding performance, with EMI SE of 60.7 dB (at X-band), high conductivity of 2.42 S/cm, and acceptable thermal conductivity of 0.7217 (W/m K). High EMI shielding performance and absorption dominant mechanism are beneficial from the unique segregated structure, and individual CNS coated UHMWPE granule are similar to an electromagnetic cage. Additionally, the ultimate tensile strength of the composite remains high at 37.6 MPa even at 10.0 wt% CNS loading, and it shows effective thermal stability. These properties are attributed to the strong interfacial bonding between CNS and UHMWPE. These materials have potential applications in efficient thermal management and EMI shielding for high-performance intelligent electrical devices.
- Published
- 2023
- Full Text
- View/download PDF
42. Research Progress on Tribology of Sliding Plate Materials for Bridge Bearings
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ZHAN Shengpeng, LI Ruize, MA Changfei, JIA Dan, DUAN Haitao, JING Guoqiang, MA Lixin, YANG Tian, LI Xiaojing
- Subjects
bridge bearing ,ptfe ,uhmwpe ,tribology ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Technology - Abstract
The sliding plate material of bridge bearing is the key part to realize the bearing, sliding and rotation of bridge bearing.This paper expounded the structure and working condition characteristics of sliding plate for bridge bearing, introduced the influence of different extreme environments on the service life and tribological properties of bridge bearing materials, summarized the research status and development trends of polytetrafluoroethylene, ultra-high molecular weight polyethylene and other typical sliding plate materials for bridge bearing, and compared their similarities and differences.On this basis, the future development trend of tribological properties of sliding plate materials for bridge bearing was analyzed.
- Published
- 2023
- Full Text
- View/download PDF
43. Design and performance of double-layered artificial chordae.
- Author
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Zhang, Tingchao, Dou, Yichen, Li, Yang, Luo, Rifang, Yang, Li, Zhang, Weiwei, Wang, Yunbing, and Zhang, Xingdong
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FATIGUE limit ,MITRAL valve insufficiency ,HYDROPHOBIC surfaces ,TENSILE strength ,BIOMATERIALS - Abstract
Surgical repair with artificial chordae replacement has emerged as a standard treatment for mitral regurgitation. Expanded polytetrafluoroethylene (ePTFE) sutures are commonly employed as artificial chordae; however, they have certain limitations, such as potential long-term rupture and undesired material/tissue response. This study introduces a novel approach to artificial chordae design, termed the New Artificial Chordae (NAC), which incorporates a double-layered structure. The NAC comprises a multi-strand braided core composed of ultra-high molecular weight polyethylene (UHMWPE) fibers as the inner core, and an outer tube made of hydrophobic porous ePTFE. Compared to traditional ePTFE sutures, NAC exhibits increased flexibility, enhanced tensile strength, longer elongation and improved fatigue resistance. Moreover, NAC exhibits a more hydrophobic surface, which contributes to enhanced hemocompatibility. The study also includes in vivo investigations conducted on animal models to evaluate the biocompatibility and functional efficacy of the artificial chordae. These experiments demonstrate the enhanced durability and biocompatibility of the NAC, characterized by improved mechanical strength, minimal tissue response and reduced thrombus formation. These findings suggest the potential application of NAC as a prosthetic chordae replacement, offering promising prospects to address the limitations associated with current artificial chordae materials and providing novel ideas and approaches for the development of sustainable and biocompatible regenerative biomaterials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. The Influences of Chemical Modifications on the Structural, Mechanical, Tribological and Adhesive Properties of Oriented UHMWPE Films.
- Author
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Dayyoub, Tarek, Kolesnikov, Evgeniy, Filippova, Olga V., Kaloshkin, Sergey D., Telyshev, Dmitry V., and Maksimkin, Aleksey V.
- Subjects
ADHESIVE tape ,MECHANICAL properties of metals ,FOURIER transform infrared spectroscopy ,POLYMERIC composites ,SCANNING electron microscopy ,ADHESIVES - Abstract
Preparing a friction pair "polymer-metal" using improved polymeric composites is contemplated a complicated task due to the inert surface of the polymer. Gluing polymer composites with improved mechanical and tribological properties on metals and saving their unique properties at the same time is considered the best way to prepare slide bearing products based on polymer/metal. In this work, ultraviolet initiation is used after a process of mixed acid pre-treatment. The surface of highly oriented films based on ultra-high molecular weight polyethylene (UHMWPE)/graphene nanoplatelets (GNP) is grafted with nanocellulose. The grafting treatment is analyzed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and contact angle measurements. Mechanical T-peel tests showed that the peel strength for the treated UHMWPE films increased by three times, up to 1.9 kg/cm, in comparison to the untreated films. The tensile strength of the treated UHMWPE films decreased by about 6% to 788 MPa. Tribological tests showed that the values of both friction coefficient and wear intensity of the treated UHMWPE films were increased insignificantly, which were 0.172 and 15.43 µm/m·m
2 , respectively. The prepared adhesive tape based on UHMWPE films, which can withstand a weight of up to 6 kg per 1 cm2 of the bonded surface, has a low coefficient of friction, high wear resistance, and high strength, and is considered a promising material for preparing slide bearing products. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
45. EFFECT OF NITRATE ACID TREATED DOLOMITE ON THE TENSILE PROPERTIES OF ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE (UHMWPE) COMPOSITES.
- Author
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ABDULLAH, S. F. A., SALEH, S. S. MD, MOHAMMAD, N. F., MAHAMUD, S. N. SYED, OMAR, M. F., AKIL, H. MD, CHANG, B. P., SALIU, H. R., ROSTAM, N. H., and GONDRO, J.
- Subjects
DOLOMITE ,CALCIUM hydroxide ,MOLECULAR weights ,DIAMMONIUM phosphate ,SUPERPHOSPHATES ,POLYETHYLENE - Abstract
Ultra-High Molecular Weight Polyethylene (UHMWPE) polymers have been used in biomedical applications due to its biocompatibility, durability, toughness and high wear resistance. To enhance the mechanical properties, various types of minerals are commonly utilized as fillers in UHMWPE. One of the minerals is dolomite, which has been recognized as a valuable mineral with versatile applications, particularly in the field of biomedical applications. This paper presents the tensile properties of UHMWPE composites that filled with dolomite and treated-dolomite at various filler loading (i.e., 1-5 wt.%). Nitric acid and diammonium phosphate were used to treat the dolomite. From the results, the peaks of the FTIR spectrum displays carbonate (CO
3 -2 ), phosphate (PO4 -3 ) and hydroxyl (OH- ) groups in the ct-dolomite powder sample while the XRD pattern reveals that using dolomite treated with 1M nitric acid resulted in the presence of calcium hydroxide phosphate (Ca10 (PO4 )5 (OH)) and MgO. For tensile strength, UHMWPE/ct-dolomite composites show better tensile strength than the pure UHMWPE composites. Treated improve the dolomite filler and resulted in significantly better matrix-filler interfacial interactions and improve the properties. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
46. Numerical Investigation on Anti-Explosion Performance of Non-Metallic Annular Protective Structures.
- Author
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Bian, Xiaobing, Yang, Lei, Wang, Tao, and Huang, Guangyan
- Subjects
- *
EXPLOSIONS , *STRAINS & stresses (Mechanics) , *SHOCK waves , *PUBLIC safety , *COMPUTER simulation - Abstract
Explosive shock wave protection is an important issue that urgently needs to be solved in the current military and public security safety fields. Non-metallic protective structures have the characteristics of being lightweight and having low secondary damage, making them an important research object in the field of equivalent protection. In this paper, the numerical simulation was performed to investigate the dynamic mechanical response of non-metallic annular protective structures under the internal blast, which were made by the continuous winding of PE fibers. The impact of various charges, the number of fiber layers, and polyurethane foam on the damage to protective structures was analyzed. The numerical results showed that 120 PE fiber layers could protect 50 g TNT equivalent explosives. However, solely increasing the thickness of fiber layers cannot effectively enhance the protection efficiency. By adding polyurethane foam in the inner layer, the stress acting on the fiber could be effectively reduced. A 30 mm thick polyurethane layer can reduce the equivalent stress of the fiber layer by 41.6%. This paper can provide some reference for the numerical simulations of non-metallic explosion protection structures. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Intra-articular replacement of the caudal cruciate ligament using a UHMWPE ligament under arthroscopic guidance in a dog: A case report.
- Author
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Fauqueux, François, Goin, Bastien, Agbalé, Mathilde, Crumière, Antonin Jean Johan, Buttin, Philippe, Viguier, Eric, and Cachon, Thibaut
- Subjects
- *
CRUCIATE ligaments , *LIGAMENTS , *DOGS , *OPERATIVE surgery , *SURGICAL indications , *KNEE - Abstract
Background: As isolated ruptures of the caudal cruciate ligament (CdCL) are rare in dogs, there is no consensus on the indications and the gold-standard surgical technique for treatment. Case Description: A 2-year-old Shepherd dog with an isolated rupture of the CdCL was treated with a new surgical technique for synthetic reconstruction. Three bone tunnels were drilled in the femur and the tibia under arthroscopic guidance to make sure the anatomical insertions of the physiological ligament were respected. An ultra-high molecular weight polyethylene (UHMWPE) implant was fixed with interference screws to reconstruct the CdCL. A synovial inflammation remained present on radiographs for 6 months after the surgery, together with a mild lameness. However, the dog fully recovered clinically and recovered a normal level of activity after 6 months. Liverpool osteoarthritis in dogs questionnaire results at 6 months and 1 year postoperatively were excellent. Conclusion: The use of a UHMWPE implant fixed with interference screws to reconstruct the CdCL allowed a return to full function of the knee without complications, despite a persistent synovial inflammation and mild lameness for a 6-month period after the surgery. The success of this isolated surgical technique could lead to improvements in the surgical management of CdCL rupture, if these initial results are confirmed by a prospective study with a larger number of patients. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. Does a Compatibilizer Enhance the Properties of Carbon Fiber-Reinforced Composites?
- Author
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Gangwani, Prashant, Kalin, Mitjan, and Emami, Nazanin
- Subjects
- *
COMPATIBILIZERS , *FIBROUS composites , *POLYPHENYLENE sulfide , *CARBON composites , *POLYMER blends , *ULTRAHIGH molecular weight polyethylene , *POLYTEF - Abstract
We have evaluated the effectiveness of compatibilizers in blends and composites produced using a solvent manufacturing process. The compatibilizers were two different types of polyethylene (linear low-density and high-density) grafted with maleic anhydride (MAH) and a highly functionalized, epoxy-based compatibilizer with the tradename Joncryl. The selected material combinations were an ultra-high-molecular-weight polyethylene (UHMWPE) with MAH-based materials as compatibilizers and a polyphenylene sulfide plus polytetrafluoroethylene (PPS-PTFE) polymer blend with an epoxy-based compatibilizer. The findings revealed that while the compatibilizers consistently enhanced the properties, such as the impact strength and hardness of PPS-based compositions, their utility is constrained to less complex compositions, such as fibrous-reinforced PPS or PPS-PTFE polymer blends. For fibrous-reinforced PPS-PTFE composites, the improvement in performance does not justify the presence of compatibilizers. In contrast, for UHMWPE compositions, compatibilizers demonstrated negligible or even detrimental effects, particularly in reinforced UHMWPE. Overall, the epoxy-based compatibilizer Joncryl stands out as the only effective option for enhancing mechanical performance. Thermal and chemical characterization indicated that the compatibilizers function as chain extenders and enhance the fiber–matrix interface in PPS-based compositions, while they remain inactive in UHMWPE-based compositions. Ultimately, the incompatibility of the compatibilizers with certain aspects of the manufacturing method and the inconsistent integration with the polymer are the main reasons for their ineffectiveness in UHMWPE compositions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. Optimization the Stab Resistance and Flexibility of Ultra-High Molecular Weight Polyethylene Knitted Structure Fabric with Response Surface Method.
- Author
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Yu, Xuliang, Su, Ting, Liang, Xinhua, and Cong, Honglian
- Subjects
- *
KNIT goods , *MOLECULAR weights , *STABBINGS (Crime) , *TEXTILE chemistry , *STRENGTH of materials , *POLYETHYLENE - Abstract
At present, the challenging issue of the compatibility between stab resistance and flexibility of materials frequently appears. Thus, this study proposes a novel method to enhance the comprehensive performance of the material matrix with stab resistance. Based on the stab-resistant mechanism analysis of the textile matrix, the influence of four factors on the performance of ultra-high molecular weight polyethylene (UHMWPE) knitted fabric was discussed. And, the optimal process conditions of material for achieving high stab resistance and high flexibility were obtained by the response surface method. A series of experiments proved that among all factors, the fabric structure had the greatest influence on the flexible stab-resistant knitted material. Following that, the thickness of the yarn also plays a significant role. Under the optimal process conditions, the stab peak force of the knitted material was promoted to 52.450 N, and the flexibility was enhanced to 93.6%. Meanwhile, through comparison with products that have undergone the same treatment, there was little difference in stab resistance but significantly improved flexibility. It achieves the initial stab resistance and comfortable wearing softness of the fabric through process optimization. This improvement in overall performance of the textile matrix enables further enhancement treatments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
50. Mechanical and biocompatibility properties of UHMWPE–HNT composite for joint replacement applications
- Author
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Hasan, Rania, Pande, Sarang, and Bhalerao, Pravin
- Published
- 2024
- Full Text
- View/download PDF
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