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Total hip arthroplasty (THA) involves the replacement of damaged or worn-out hip components with artificial implants. Frequently revision surgeries were performed due to the failure of the implant. The liners are the ones that are replaced in the majority of the revision surgeries. Researchers are constantly finding different materials to overcome the difficulties being faced. The acetabular liners are fabricated by compression molding and milling using single materials such as Polyethylene, Polyether-ether-ketone (PEEK), and recently Ultra-High Molecular Weight Polyethylene (UHMWPE), and so forth. Poly Lactic Acid (PLA) being biocompatible and cheaper than UHMWPE is employed in the research. The biodegradable nature of PLA is countered by introducing a nonbiodegradable yet biocompatible High Impact Polystyrene (HIPS). This research attempts to propose and fabricate a novel design of the liner with PLA sandwiched between HIPS by fused filament fabrication, the widely used additive manufacturing technique. The dimensional accuracy and surface roughness of the liners are measured and compared with single- material liners. The multi-material liner demonstrated superior dimensional accuracy compared to PLA liner and also exhibiting a smoother surface finish. Dynamic Mechanical Analysis is conducted to determine the capability of printing and also the scanning electron microscopic (SEM) images are used for supporting the results. Highlights * Novel design of Acetabular Liner. * Use of additive manufacturing for fabrication of implant parts. * More than one material used to reap benefits from the two materials used. * Measurement of dimensional accuracy, surface roughness of multi- material liner. * Comparison of single and multi-material liner. KEYWORDS additive manufacturing, biocompatible, biodegradable, implant, 1 | INTRODUCTION Total hip arthroplasty (THA), commonly known as total hip replacement (THR), is a surgical procedure that involves replacing a damaged or diseased hip joint with an artificial [...]

Photocrosslinking of polymers for industrial applications show undoubted advantages related to the mild conditions needed and the economical equipment. However, some issues include: the use of (i) mercury lamps as light sources, which poses concerns about safety and energy consumption, (ii) typical additives, such as halogen-free flame-retardant fillers (HFFR) are powdered materials, which can scatter UV photons and avoid a deep penetration of the light. In this study, we explore the UV-curing of an innovative EVA-POE blend containing hydrotalcite and aluminum hydroxide as HFFR in the presence of a 370-nm UV LED, namely Ekopren[R] XI1321, a plastic used as coverage for electric cables. Two commercially available photoinitiators (benzophenone and ethyl Michler's ketone) were analyzed as well as two crosslinking coagents widely used in industry, that is, triallyl cyanurate and trimethylolpropane trimethacrylate. A comparison with pure EVA and LDPE was performed to show a higher cross-linked content of the proposed blend, even in the presence of light scattering mineral fillers at high concentration. KEYWORDS crosslinking, curing of polymers, flame retardance, initiators, irradiation, 1 | INTRODUCTION Polymers are probably the most versatile materials available nowadays. By engineering both the nature of the monomers and the structure in which the monomers are linked together, [...]

With the development of degradation technologies such as chemical-catalysis and bio-catalysis, starch-polyethylene (PE) composites have been revitalized as industrial packaging materials. However, starch and PE suffer from interfacial incompatibility. In this study, poly(octene ethylene) grafted glycidyl methacrylate (POE-g-GMA) was added at relatively low amounts (0-7 wt%) to construct robust structures between thermoplastic starch (TPS) and low-density polyethylene (LDPE). Tensile strength increased by 36.39% with the addition of 1 wt% POE-g-GMA. Meanwhile, a smooth surface was observed by SEM, and a fibrillar cross-linked structure appeared on the fractural surface of the blend. POE-g-GMA formed a stable 'bridge' at the interface between TPS and LDPE, which increased the thermal stability of the blend as well. The crystallinity of LDPE increased from 20.5% (without addition) to 32.8% (with 1 wt% addition), whereas the average crystallite size decreased slightly. The optimal POE-g-GMA content was found to be 1 wt% based on mechanical and thermal measurements. The results of this study can provide a reference for improving the interfacial compatibility of biopolymers and fossil-fuel-based polymers. KEYWORDS compatibilization, composites, differential scanning calorimetry, mechanical properties, polyethylene, orcid.org/0000-0002-1316-8166 1 | INTRODUCTION Starch is a natural, renewable, low-cost, full-degradable material that can be used to produce biodegradable plastics with wide applications, such as shopping bags, mulch, and film. [...]

Background: The constrained posterior-stabilized (CPS) implant for use in total knee arthroplasty (TKA) has a constraint level midway between that of a posteriorstabilized implant and a valgus-varus-constrained implant; there is currently no consensus on the surgical indications for use of this degree of constraint. We present our experience using this implant at our centre. Methods: We reviewed the charts of patients who received a CPS polyethylene insert during TKA in our centre between January 2016 and April 2020. We collected patient demographic characteristics, surgical indications, pre- and postoperative radiographs, and complications. Results: A total of 85 patients (74 females and 11 males with a mean age of 73 yr [standard deviation 9.4 yr, range 36-88 yr]) (85 knees) received a CPS insert over the study period. Of the 85 cases, 80 (94%) were primary TKA and 5 (6%) were revision TKA. The most common indications for primary CPS use were severe valgus deformity with medial soft-tissue laxity (29 patients [34%]), medial soft-tissue laxity without substantial deformity (27 [32%]) and severe varus deformity with lateral soft-tissue laxity (13 [15%]). The indications for the 5 patients who underwent revision TKA were medial laxity (4 patients) and an iatrogenic lateral condyle fracture (1 patient). Four patients had postoperative complications. The 30-day return to hospital rate was 2.3% (owing to infection and hematoma). A single patient required revision surgery for periprosthetic joint infection. Conclusion: We found excellent short-term survivorship of the CPS polyethylene insert when used for a spectrum of coronal plane ligamentous imbalances with or without preoperative coronal plane deformities. Long-term follow-up of these cases will be important to identify adverse outcomes such as loosening or polyethylene-related problems. Contexte : La prothese postero-stabilisee cimentee en arthroplastie totale du genou (ATG) a un degre de contrainte entre la prothese postero-stabilisee et la prothese semi-contrainte. L'indication chirurgicale de ce degre de contrainte ne fait pas encore consensus. Cet article presente l'experience de notre centre avec cette prothese. Methodes : Nous avons analyse les dossiers de patients ayant recu un insert posterostabilise cimente en polyethylene au cours d'une ATG dans notre centre entre janvier 2016 et avril 2020. Nous avons recueilli les caracteristiques demographiques, l'indication de l'intervention, les radiographies pre- et postoperatoires et les complications. Resultats : Au total, 85 patients (74 femmes et 11 hommes, age moyen 73 ans [ecarttype 9,4 ans, intervalle 36-88 ans]) ont recu un insert postero-stabilise cimente pendant la periode de l'etude. Il s'agissait d'une ATG de premiere intention pour 80 (94 %) des cas et de reprise pour 5 (6 %) d'entre eux. Les indications les plus frequentes pour la prothese postero-stabilisee cimentee de premiere intention etaient une deformation valgus grave avec laxite ligamentaire interne (29 patients [34 %]), une laxite ligamen taire interne sans deformation majeure (27 patients [32 %]) et une deformation valgus grave avec laxite ligamentaire externe (13 patients [15 %]). Pour les 5 ATG de reprise, les indications etaient une laxite interne (4 patients) et une fracture iatrogene du condyle lateral (1 patient). Des complications postoperatoires sont survenues chez 4 patients, avec un taux de retour a l'hopital dans les 30 jours a 2,3 % (pour une infection et un hematome). Un seul patient a necessite une chirurgie de reprise pour une infection de prothese articulaire. Conclusion : Nous avons obtenu une excellente survie prothetique a court terme de l'insert postero-stabilise cimente en polyethylene utilise dans toutes sortes de desequilibres ligamentaires frontaux avec ou sans deformations frontales preoperatoires. Il est important de suivre ces cas a long terme pour reperer les effets indesirables tels que le descellement ou des problemes lies au polyethylene., Total knee arthroplasty (TKA) can decrease pain and improve quality of life substantially in patients with knee arthritis. (1) With increasing demand owing to an aging population, the number of [...]

Experiments were conducted to quantify short-term tensile strains induced in a 1.5 mm thick high-density polyethylene geomembrane overlain by tailings. Four subgrades, a poorly graded angular to subangular gravel (GP), a well-graded angular to subangular gravel (GW), a poorly subrounded graded sand (SP), and silty sand (SM), and two nonwoven geotextiles, 450 and 1420 g/[m.sup.2], were evaluated. All the indentations in the geomembrane (GMB) were due to the subgrade, and with an adequate fraction of sand size particles in the subgrade, the tensile strains could be minimized. At 2000 kPa, the maximum tensile strain was 32% for GP, 16% for GW, 13% for SP, and no discernable indentation was observed for SM prepared at the optimum water content of 11%. For the soft SM subgrade prepared at 20% water content, only one indentation with the tensile strain of 2% was observed. At 2000 kPa, a 450 g/[m.sup.2] geotextile beneath the GMB reduced the maximum tensile strain from 32% to 23% for GP subgrade, from 16% to 8% for GW subgrade, and from 13% to 6% for SP subgrade; the 1420 g/[m.sup.2] geotextile reduced the maximum tensile strain to 14% for GP subgrade. Thus, minimal subgrade indentation induced strain and hence the possibility of a very long service life of GMB could be achieved using SM subgrade. Key words: geosynthetics, geomembrane, geotextile, tailings, geomembrane strain, 1. Introduction Tailings storage facilities (TSFs) are engineered structures constructed to impound slurry, thickened, and paste tailings resulting from mineral processing activities. With the increase in the footprint of mining [...]

Gore's expanded polyethylene membrane and Bionic's recycled plastics give the StormShadow parka performance and sustainability. Eco-minded outdoor apparel company Patagonia Inc. has partnered with two materials firms to produce one [...]

Abstract A series of polyethylene terephthalate-polyethylene naphthalate (PETN) copolymer films with excellent oxygen barrier properties were prepared by introducing trace amounts of hydroxy-terminated polybutadiene (HTPB) into PETN via in-situ polymerization. [...]

This study deals with the effect of two types of conductive fillers (viz., boron nitride and single walled carbon nanotubes) on the properties of the linear low-density polyethylene (LLDPE) matrix and LLDPE/paraffin wax (PW) blend. Pure LLDPE and paraffin wax/LLDPE blend (30/70) were melt mixed with 2 wt% content of boron nitride (BN) and single walled carbon nanotube (SWCNT), as well as their synergy at 2 wt%. Because it is wellknown that both conductive fillers were able to improve the thermal conductivity of the paraffin wax/polymer blends, the aim of this study was to focus on the effect of both conductive fillers on the dispersion of paraffin wax into LLDPE matrix, mechanical properties, crystallization behavior, and thermal stability of the LLDPE/wax blend. Scanning electron microscopy (SEM) images of the LLDPE/paraffin wax blends depicted a phase separated system, which was further supported by two separate peaks from the differential scanning calorimetry (DSC). The morphology of the system showed that the addition of boron nitride (BN) into the LLDPE/paraffin wax blend had no affinity with the paraffin wax, while the addition of single walled carbon nanotubes (SWCNT) showed better dispersion into the LLDPE/paraffin wax/BN blend composites. The incorporation of the SWCNT and its synergy with BN enhanced the thermal stability of the LLDPE. KEYWORDS boron nitride, conductive filler, LLDPE, paraffin wax, single walled carbon nanotubes, 1 | INTRODUCTION Renewable and sustainable energy is in high demand due to the intensity of energy consumption and population growth that is causing a major problem in the modern [...]

Abstract The poor tribological performance of epoxy limits its application in the field of lubrication and wear protection, but there is still great potential for improvement. In this paper, polyethylene [...]

Hole transport properties and Current-Voltage characteristics of the single-layer device in an inverted structure were investigated with spin-coated PEO/PVP/ Cobalt nitrate polyblend electrolyte film as an active layer. A strong correlation between morphology and ionic conductivity was confirmed through XRD, DSCTGA, SEM and fluorescence spectroscopic techniques. The optical band gap values are in good agreement with the electrochemical band gap. Schottky diode measurements confirmed the formation of p-type semiconductors with PEO/PVP bulk films with cobalt nitrate as a dopant at room temperature. The I-V characteristics are strongly dependent on the salt concentration in the polymer blend. The parameters of diodes such as barrier height, saturation current, and charge carrier concentration were calculated from I-V characteristics. From C-V characteristics a charge carrier concentration in the range of [10.sup.22] [cm.sup.-3] was obtained for the highest concentration of cobalt nitrate salt in the PEO/PVP blend. A very low energy barrier for hole injection at the anode [DELTA][E.sub.h] = 0.28 eV was observed. KEYWORDS amorphousity, charge transport, electrochemical band gap, optical band gap, poly-blend electrolyte, 1 | INTRODUCTION Organic light-emitting diodes (OLEDs) and solar cells (OSCs) comprised of polymeric materials have recently been studied widely because of their potential for applications in optoelectronic devices and [...]

A series of novel intumescent flame retardant (IFR) based on melamine, neopentyl glycol, and aluminum diethylphosphinate were prepared and tested. In addition, the synergistic effect of the novel IFR and zinc borate (ZB) on the flame retardancy of LLDPE composites was investigated. The structures of novel IFR and ZB were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The limiting oxygen index (LOI) increased from 19.3% for the pure LLDPE to 27% for the 25 wt% IFR/5 wt% ZB composites and the composites achieved the desired V-0 rating in the UL-94 test. Thermogravimetric analysis showed that the addition of IFR/ZB reduced the pyrolysis rate of the LLDPE composites at high temperatures and increased the amount of the char residues, and the char residue of LLDPE-5 reached 12.1 wt% at 700[degrees]C. Cone calorimetry (CCT) data showed that the peak of total heat release, heat release rate, and fire growth index were comparatively reduced, indicating that the addition of IFR/ZB decreased the fire hazard of LLDPE composites. The formation of a compact and thermally stable char layer on the surfaces of LLDPE composites was revealed from the scanning electrone microscopy images and digital photographs of the char residue after the CCT tests. KEYWORDS composites, flame retardant, polyethylene, synthesis, thermal properties, 1 | INTRODUCTION Polyethylene (PE) is a typical thermoplastic that currently has the highest production volume among the five general-purpose plastics. Polyethylene is used in a wide range of applications [...]

Linear low-density polyethylene (LLDPE) 7042, which has a butene comonomer, is widely used but has poor tear and dart strengths. For practical applications, small amounts of other materials can be blended with 7042 to effectively improve its properties. In this study, four blend resins and films (cast and compressed films) were prepared by blending 7042 with four LLDPEs (2045G, 9030, 23F, and 9085) in 8:2 ratios. The results indicated that after blending 2045G, 23F, or 9030 with 7042, the crystallization ability of the three blends was significantly suppressed and crystal size decreased. Moreover, the molecular chain can pass though more lamellar stacks in the blends, leading to an increased tie-chain concentration. Therefore, the tear and dart impact strength of the blend films improved. In contrast, the crystallization ability of the 7042/9085 blend was only slightly suppressed and did not significantly impact its properties. These findings contribute to our understanding of the relationship between material structures and properties, demonstrating that LLDPE blends can be used to improve the tear and dart strengths of 7042. KEYWORDS blends, comonomers, crystallization behavior, linear low-density polyethylene, structure and properties, tie-chain, 1 | INTRODUCTION Linear low-density polyethylene (LLDPE) is a random copolymer of ethylene and [alpha]-olefin, which is synthesized using Ziegler-Natta or metallocene catalysts. LLDPE is widely used in the polymer [...]

Poly (lactic acid) (PLA) and Linear low-density polyethylene (LLDPE) were compounded in a corotating twin screw extruder. PE-g-glycidyl methacrylate was also added as a reactive compatibilizer in PLA/LLDPE blend system, which lowered interfacial tension between PLA and LLDPE. Blown films were prepared by using a single-screw extruder for all compounded blends. The investigation of the rheological properties of a polymeric system is very important to study the processability and understand structure-property relationship in blown films. In the present research work, the rheological properties have been investigated to assess the processability of blown films of PLA/LLDPE blends. Oscillatory shear rheology viscoelastic spectra showed an increase in the storage and loss moduli with the increase in LLDPE and compatibilizer content, which indicated pronounced viscoelastic behavior of PLA with the addition of LLDPE and compatibilizer. A steady increase in the value of extensional viscosity as a function of time was observed with the addition of LLDPE and compatibilizer in PLA. The blends with higher LLDPE content exhibited much more prominent strain hardening characteristics than those with lower LLDPE content. KEYWORDS blends, film processability, LLDPE, PLA, rheology, 1 | INTRODUCTION Film blowing is one of the widely used processes at packaging industry. Bubble instability during the film blowing process, can be successfully obtained to a greater perfection [...]

Cellulose nanocrystals (CNCs) have emerged as fillers of interest to the polymer nanocomposite community due to their inherent properties and renewable precursors. However, challenges persist to incorporate CNCs into polymer matrices due to component incompatibility and/or thermal stability limitations of the nanoparticles. Therefore, the objective of this research is to examine the efficacy of different processing methods in producing CNC/polymer composites. In this work, CNCs were incorporated into polyethylene-co-vinyl alcohol (EVOH) using either a solution casting method or a multi-step method involving the same solution casting method followed by a melt mixing step. The resulting neat EVOH and composite materials were characterized to understand how the viscoelastic character and mechanical properties were influenced by CNC loading and processing method. The results of characterization experiments and micromechanical modeling suggested that the nanoparticle networks produced by each method were different and that a combined solution-melt processing method is beneficial in producing composites with improved properties, particularly at higher CNC loadings. This processing strategy may be more broadly applied to other nanocomposites. KEYWORDS mechanical properties, nanocomposites, viscoelastic properties, nanofibers, networks, processing, 1 | INTRODUCTION Cellulosic nanomaterials have garnered significant attention for use in polymer nanocomposites for a variety of reasons. Their physical dimensions and theoretical mechanical properties offer opportunities for increased [...]

Two novel flame retardant and anti-dripping PE films were successfully synthesized in three steps. PE-g-GMA film was first prepared by simultaneous electron beam irradiation to graft glycidyl methacrylate (GMA) onto PE film. 4,4'-[1,4-phenyl-bis(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl) dimethyneimino)]diphenol (DOPO-t) and 4,4'-[1,3-phenyl-bis (9,10-dihydro-9 -oxa-10-phosphaphenanthrene-10-yl)dimethyneimino)]diphenol (DOPO-m) were then fabricated via a one-pot method. Finally, two DOPO derivative functionalized PE films were obtained through the ring opening reactions of PE-g-GMA film with DOPO-t and DOPO-m, respectively. Combustion properties, flame retardancy, thermal performance, and thermal shrinkage of these films were evaluated. Compared with pure PE film, the burning rate of antidripping DOPO-t/DOPO-m functionalized PE films was reduced by 13.2% and 50.0%, and the limiting oxygen index value climbed to 18.5 and 19.5, respectively. The residual chars from DOPO-t/DOPO-m functionalized PE films at 700[degrees]C were increased, and the shrinkage ratio decreased remarkably, which could effectively prevent the spread of fire. We also discussed the effect of structural difference between DOPO-t and DOPO-m on the above properties and the flame retardant mechanism of two DOPO derivative functionalized PE films preliminarily. This work provides a method for introducing DOPO derivatives into PE molecules to improve their flame retardancy and anti-dripping properties. KEYWORDS anti-dripping performance, DOPO functionalized polymer, flame retardancy, irradiation grafting, polyethylene film, 1 | INTRODUCTION Polyethylene (PE) is a kind of thermoplastic polymer with the largest consumption nowadays, [1] applied to be as membranes, pipes, utility wires, and encapsulated materials because of [...]

Herein, the oil/water separation property of four polyethylene (PE) foams with two different volume expansion ratios including 15 and 30 times was studied. We found that the PE-30-1 foam was the best absorbent materials among these four samples, which was also superior to the commercially available products. It demonstrated high oil absorption capacities, as well as high oil/water selectivity, which was due to its small average pore size and high porosity. In addition, this work also reports two rapid and straightforward methods to fabricate PE-30-1-ZIF-8 composite with enhanced compressive property, an encouraging absorption capacity for different organic solvents, reaching 59 times of its own weight for chloroform, as well as increased oil-water selectivity of the system. Comparing with the PE foam, the organic solvent absorption capacities for PE-ZIF-8-sono composite foams were improved by 6.4%, 29%, 9.1%, and 12% for chloroform, acetone, toluene and oleic acid, respectively, while the corresponding improvement for PE-ZIF-8-Me(OH) was about 7.5%, 28%, 14%, and 15%, respectively. These PE-ZIF-8 foams could reach the requirement for oil spill cleanup, suggesting its great potential for this type of application., INTRODUCTION With the fast-growing energy demand, offshore drilling of oil has increased, and the chances of oil spillage of production and transportation have enormously increased. In the last few years, [...]

The extrusion-calendering process was realized successfully to produce the potential and easily recyclable single-polymer composites (SPCs). This approach makes it possible to produce SPCs continuously and avoids the drawbacks involving a long cycle time, inconvenient operation, and expensive cost. Low-density polyethylene (LDPE) reinforced with ultrahigh molecular weight polyethylene (UHMWPE) fabric was prepared. Based on orthogonal and single factor experiments, the effects of die temperature, screw speed, and rolls speed were investigated. The tensile and interfacial properties of the LDPE/UHMWPE SPCs were evaluated through tensile and T-peel tests. The best tensile strength of 78.8 [+ or -] 7 MPa was obtained in the LDPE/ UHWMPE SPCs with a fiber volume fraction of 11.2% and a void content of 0.01%. The peel strength was significantly improved, 22.4 N/10 mm was achieved. The morphology observed using scanning electron microscopy (SEM) further determined the fiber-matrix interfacial adhesion and the effects of processing parameters. POLYM. ENG. SCI., 58:2156-2165, 2018. [C] 2018 Society of Plastics Engineers, INTRODUCTIONThe recyclability of composites still reminds a key topic to the pressures of resource and environment in recent years. However, heterogeneous compositions and special structures in traditional polymer composites strictly [...]