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Purpose: To evaluate the effect of immersion in water on deforma8on of maxillary denture bases created with CAD/CAM and heat-polymerized resin fabrica8on techniques under loading condi8ons. Materials and Methods: 2-mm-thick denture bases were fabricated using four techniques: CAD/CAM milling (CCM; Polywax PMMA blank, Yamachi PMMA disk Yamahachi Dental); 3D prin8ng (3DP; BV005, NextDent Base); compression molding (CM; Luciton 199, Dentsply Sirona); and injec8on molding (IM; Ivobase, Ivoclar; n = 5 per group). Three sta8c 49-N loads were applied perpendicular to each denture base, and the mean strain value (MSV) was recorded with strain gauges a[ached to the denture surface. The denture bases were stored at 37°C in dis8lled water for 14 and 28 days, and the MSVs under the same sta8c load were recorded. Results: The highest MSVs were observed at the posterior palatal seal, tuberosity, and labial notches of the dentures. The lowest MSVs were recorded for the CCM group and then the CM and IM groups. The highest MSVs were recorded for the 3DP group. No significant differences in regional MSVs (P > .05) were observed among the CCM, CM, and IM aber 14 and 28 days in water. Large devia8ons in MSVs were recorded for the 3DP group across the measurement sites aber water exposure (P < .05). Conclusions: CCM had the lowest denture deforma8on under sta8c loading. Aber immersion in water, the deforma8on changes under sta8c loading were stable for CCM, CM, and IM. However, varia8ons among the materials used in 3DP group influenced the mechanical performance and presented larger deformations. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) poses significant challenges to the reliable operation of communication systems, medical devices, and electronic equipment, often resulting in signal degradation, data loss, and equipment failure. To mitigate these issues, this study investigates the development of barium hexaferrite (BHF)/polyvinylidene fluoride (PVDF) composites, synthesized via compression molding, to optimize their electrical and magnetic properties for high-frequency EMI shielding applications. Through comprehensive characterization, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), and vector network analysis (VNA), we demonstrate that increasing the BHF content within the composites enhances their complex permittivity, impedance matching, and attenuation coefficients, making them highly effective for EMI shielding. Notably, the composite containing 20 wt% PVDF achieved a reflection loss (RL) of −42 dB at a thickness of 2 mm, indicating superior shielding effectiveness. These results underscore the potential of BHF/PVDF composites as a viable solution for advanced EMI suppression in high-frequency electronic and military applications, combining economic feasibility with robust performance. [ABSTRACT FROM AUTHOR]

In this study, tests were conducted to examine the morphological, mechanical, and wetting properties of thermoplastic composites using banana fiber (BF) an agro-residue as a filler. Plasma-treated polyethylene (PPE) was used as the matrix, and compression molding technique was used for composite preparation. Treated and untreated polyethylene (UPE) banana fiber composites were compared in terms of the interfacial adhesion between the fiber and the matrix. Fibers were added in varying amount (10, 20, 30, and 40 by weight %) into the polymer to investigate the fiber-matrix interaction in each case and also to optimize the composition that would yield improved properties. Morphological properties were studied using scanning electron microscopic (SEM) studies, surface wettability was studied using the contact angle method and FTIR analysis was used to confirm the effectiveness of the functionalization. SEM analysis showed that PPE-BF composites have better interfacial adhesion between the polymer and fiber as compared to UPE-BF composites. Also, PPE-BF showed a maximum of 6% and 25% increment in tensile strength and Young's modulus. Wettability studies showed that contact angle values got decreased from 93° (UPE-BF20) to 77° (PPE-BF20), which proves the effectiveness of plasma treatment through incorporation of new functionalization (polar groups) on the surface of the polymer in treated composites, and also which shows how the treatment enhanced the interfacial bonding between polymer and fiber. [ABSTRACT FROM AUTHOR]

This article is presented as a study of combined threaded connections used in mechanical engineering and oil field volumetric hydraulic drive devices and other areas. The issue of creating combined reinforcement by pressing and casting a part from a plastic mass onto a metal reinforcement comes to the fore. It has been established that the profile and pitch of the thread should be selected from the same calculation of the strength of the thread made of metal and thermoplastic, the determining role in the calculation is played by the length of the thread, which is one of the main parameters. The minimum wall thickness is selected using thread profiles. The study showed that the shear strength of thermoplastic materials differs significantly from that of metallic materials. The dependence of the shear strength limit along the length of various threaded connections relates to the lengths of the metal reinforcement and its corresponding thickness. This article attempts to study the dependence of the shear strength of combined threaded connections on the thread parameters of the metal reinforcement part, the mode of joining thermoplastic molding with pressing, the diameter of the reinforcement, the wall thickness of the thermoplastic, and the length of the thread. [ABSTRACT FROM AUTHOR]

Powder molding technology is a versatile process widely used in the pharmaceutical, ceramic, chemical, food, and powder metallurgy industries. The powder-filling mold process is a key link in powder compression molding, and the uniformity and consistency of powder filling directly affect the final quality of powder products. Powder filling of molds is a more complex flow process. This paper first reviews the methods used to test powder flow characteristics and comments on their applicability to the mold-filling process, provides an in-depth discussion of four different filling techniques, focusing on the flow behavior of the powder during the filling process, and analyzes the effects of powder characteristics and process parameters on the filling effect. By reviewing the latest advances and identifying the key challenges, a valuable reference is provided for the mold-filling process. [ABSTRACT FROM AUTHOR]

In this study, a silane-treated sunn hemp fiber in a polyester resin and rubber seed husk cellulose toughened Acrylonitrile butadiene styrene honeycomb core were used to create a high-toughness, sudden energy-absorbing, environmentally sustainable composite. Materials include polyester resin, sunn hemp fiber, silane-treated cellulose derived from rubber seed husks, and methyl ethyl ketone peroxide as a catalyst. Using a fused deposition modeling printer, the honeycomb structure is manufactured. The composite materials were created by hand layup and post-cured for 48 h at 120 °C. The cured composites were then characterized in compliance with the American Society for Testing and Materials guidelines. The incorporation of 30% sunn hemp fiber and 10% ABS considerably improves the composites' fatigue behavior, impact resistance, and mechanical properties. According to the results, the composite containing 4.0 phr of silane-treated cellulose is noteworthy for achieving maximum values of 5.8 J for Izod impact, 209 MPa for flexural strength, 7.7 GPa for tensile strength, and 8.24 GPa for flexural modulus. In a comparable way, the composite RAC5 with a 4.0 phr cellulose content generated a maximum fatigue count of 27,841 for 25% of UTS throughout its fatigue cycles. Significant improvements were observed in the thermal stability, with the decomposition temperatures rising as high as 541 °C. The inclusion of reinforcements treated with silane resulted in improved bonding with polyester resin, as confirmed by the SEM study. According to the study's findings, these composites, which are distinguished by their excellent performance, low weight, and durability, have prospective uses in the automotive, sports, construction, and UAV industries. [ABSTRACT FROM AUTHOR]

In recent days, synthetic fibers are replaced by natural fibers in composite materials, due to their eco-friendly nature. Because of this reason, in this research work, the Caryota fibers were extracted from the fishtail form tree and to investigate the static mechanical, thermal, and water absorption properties. The mechanical properties of 6ATCF composite had occurred the maximum tensile strength (72.24 MPa), flexural strength (71.03 MPa), and impact strength of (9.36 kJ/m2) in the static mechanical analysis due to their good bonding between the fiber and matrix. Comparably, the 6ATCF composite had 43%, 38%, and 44% improvement in the tensile, flexural, and impact to the 2UTCF composite. The 2UTCF has observed more amount of water absorption weight percentage, because of the shortening of fiber length in the composite. However, the 8ATCF composite had provided a high residual mass of 22.56% and low thermal conductivity of 0.189 W/m–K in the thermal analysis compared to the other composition. In addition, for finding the interfacial properties of surface roughness of fiber, fiber fracture, fiber pullout, matrix crack, and voids are analyzed using scanning electron microscope (SEM) and atomic force microscope (AFM). Subsequently, the natural composite is utilized as a substitute material for roof sheets and to reduce heat transfer through buildings and energy conservation. [ABSTRACT FROM AUTHOR]

Owing to the outstanding properties of boron carbide (B4C) particles, material researchers have shown potential in filler‐reinforced polymer composites. The present work studied the implication of B4C fillers on the mechanical and ballistic properties of glass fiber epoxy reinforced composites. Two different weight percentages of 2 and 4 wt% B4C fillers were used to modify the epoxy resin. The composite samples with glass fabric woven were made through compression molding. The results show that the tensile, flexural, interlaminar, impact strength and hardness of glass fiber composite were improved by addition of 2 wt% of B4C. The high‐velocity ballistic tests were conducted on the unfilled and B4C filler‐reinforced composites using a 9 mm parabellum projectile with an initial striking of 372 ± 15 m/s. The least back face signature (BFS) and highest specific energy absorption (SEA) were observed for 2 wt% B4C filler composite. Adding B4C filler enhanced matrix toughening and interfacial bonding between fiber and matrix. Matrix cracking and fiber breakage result in the least ballistic resistance for unfilled composite. Fracture behavior was studied on tensile, impact, and ballistic‐tested samples using scanning electron microscopy. The fractured surfaces of filler‐reinforced composite demonstrated good interfacial bonding, matrix hardening, and fiber pullouts. Highlights: The addition of B4C with epoxy up to 2 wt% improves the mechanical and ballistic properties of the composites.The least back face signature and highest specific energy absorption were observed for 2 wt% B4C filler composite.B4C filler enhanced matrix toughening and interfacial bonding between fiber and matrix.Failure of unfilled glass fiber composites is a combination of matrix cracking, fiber pullout, and interface debonding. [ABSTRACT FROM AUTHOR]

Highlights Hot compression molding was used to produce biocomposites from ramie plain‐woven fabric‐reinforced polylactic acid (PLA). Prior to composite fabrication, alkali and dipodal silane (bis(3‐trimethoxysilylpropyl) amine) (BAS) were applied to improve fiber‐matrix adhesion. Mechanical tests revealed improvements in tensile and flexural strength due to interfacial adhesion. The flexural strength of ramie PLA composite samples treated only with silane (SR‐PLA) was the highest, at 136.35 MPa. Young's modulus was 7.51 GPa. BAS treatment was crucial for ensuring strong adhesion between the fabric and the PLA matrix. In combined alkali‐BAS‐treated composites (ASR‐PLA), the glass transition and crystallization temperatures disappeared completely, affecting PLA morphology. The maximum heat of absorption (373°C) was found in SR‐PLA composites, suggesting electrostatic interactions created a three‐dimensional network. In conclusion, the initial incorporation of dipodal silane resulted in the formation of six silanol linkages with ramie fabric, leading to enhancements in the mechanical and thermal characteristics of ramie–PLA composites. Alkali and BAS treated Fabrics ironed to remove treatment‐induced wrinkles. Carded PLA fiber with consistent density and weighted in four equal portions. Fabric and PLA lay alternatively in warp direction before compression molding. SR‐PLA composites exhibited improved thermal and mechanical properties. [ABSTRACT FROM AUTHOR]

Highlights Biodegradable biobased polymers are a promising solution to reduce the dependence on conventional plastics and minimize their environmental impact. This work evaluated the recycling capacity of a biodegradable polymer (MaterBi) and its composite with agave fibers. The materials were reprocessed by several cycles using compression molding. Service life simulation was performed using accelerated weathering. Samples from each reprocessing cycle were characterized in terms of melt flow index (MFI), color, porosity, water absorption, compostability, and mechanical and thermal properties. The MFI of MaterBi increased with each cycle, going from 3.5 to 95 g/10 min for the first to sixth cycles and from 2 to 117 g/10 min for the first and fourth cycles for the biocomposite. Reprocessing produced chain scission and modified the thermal and mechanical properties. MaterBi exhibited competitive mechanical properties compared to conventional polymers, even after four reprocessing cycles (tensile, flexural, and impact strengths of 27, 55 MPa, and 30 J/m). Besides potential cost reductions, the agave fiber addition positively affected the tensile and flexural modulus, which remained after the fourth cycle in 1100 and 2300 MPa. The results confirmed that MaterBi and its biocomposites can be recycled for several cycles, extending their useful life before final biodegradation. MaterBi (MB) and its agave fiber biocomposites are suitable for reprocessing. MB tensile and flexural properties remained stable after four reprocessing cycles. Agave fibers make MB more prone to weathering, impacting its properties. MB and its biocomposites degrade in water and compost conditions. [ABSTRACT FROM AUTHOR]

Highlights The bio‐sandwich composites are lightweight, economical, recyclable, and easily obtainable. Sandwich panels comprising glass fiber/epoxy face sheets and hemp fiber/epoxy core with varying fiber orientations, thickness, and montmorillonite nanoclay are prepared by stirring the epoxy/clay mixture to have uniform dispersion followed by compression molding. The sandwich and monolithic composites are loaded under quasi‐static punch shear. The sandwich panel with 3 wt.% nanoclay shows optimum quasi‐static tensile modulus and strength than the neat panel. Energy absorption, and specific energy absorption of sandwich panels G0/H(0)5/G0‐0%, G0/H(0)10/G0‐0%, G0/H(0)15/G0‐0% are 2%, 76%, 111%, and 28%, 132%, 183% higher than same weight glass/epoxy composites G(0)5‐0%, G(0)8‐0%, G(0)10‐0%. Energy absorption and specific energy absorption of panels G0/H(0)3/G0‐3%, G0/H(0)7/G0‐3%, G0/H(0)9/G0‐3% are similar, 25%, 24%, and 18%, 55%, 57% higher than same thickness composites G(0)5‐0%, G(0)8‐0%, G(0)10‐0%. The energy absorption of sandwich panel G0/90/H(0)15/G90/0‐0% is 49% lower than same weight composite G0/90/(0)9/90/0‐0%. Similar behavior is observed for panels with ±45° face sheets, 0° core, and 0°/90° face sheets, ±45° core compared to composites. Therefore, sandwich panels with 0° face sheets and core outperform composites and can replace them in structural applications in automotive. Particularly, panels show greater improvement over same‐weight composites than same‐thickness ones. Energy absorption of sandwich panels having 0° and ±45° cores is comparable while it is higher than a panel with 0°/90° core, each of 0°/90° face sheets. This is observed for monolithic composites as well. The quasi‐static indentation response of bio‐sandwich composites is examined. Bio‐sandwich composites outperform synthetic composites, each of the same weight. Bio‐sandwich panels with 3 wt. % nanoclay perform better than the same thickness synthetic composites. The behavior of sandwich and monolithic composites varies with fiber orientations. [ABSTRACT FROM AUTHOR]

This study presents a discrete element numerical model for the unidirectional compaction of microfine magnesite powder, designed to enhance the green body density based on laboratory apparatus configurations. The research demonstrated that as particle size decreased, porosity significantly reduced and density increased, resulting in a more uniform internal distribution within the green body. This led to closer particle contacts and an increased coordination number, which in turn intensified inter-particle interactions and the effectiveness of force transmission. During compaction, the distribution of force chains became more uniform, reducing localized stress concentrations and enhancing the mechanical integrity of the green body. The stress–strain relationship followed a polynomial pattern, highlighting the significant influence of particle size on the mechanical behavior during compaction. These findings provide a valuable theoretical basis for optimizing the compression molding process of microfine magnesite powder, facilitating the production of high-density, high-performance molded products. [ABSTRACT FROM AUTHOR]

Superhydrophobic microarchitectured polyolefin surfaces are currently used intensively in various industrial applications. However, the deployment of products made of these materials into practical application is typically constrained by their inferior dry sliding behaviors, which stem from their limited strength and toughness. To obtain reinforced and toughened superhydrophobic microstructured surfaces that can be easy to demold and overcome friction in the workplace, elastomeric ethylene–octene copolymer (POE) and rigid graphene (GP) were introduced into the polypropylene (PP) matrix to prepare microstructured PP/POE/GP surfaces by compression molding. The elongation at break is significantly improved by 2000% and reached up to 520.33%. The contact angle (CA) of the microstructured PP/POE/GP surface increases to 154.4°. They exhibit superhydrophobic and low adhesion characteristic, that is, lotus effect. The enhanced toughness of PP/POE/GP composites reduces wear debris and damage to microarchitecture during the abrasion process. Even after the microstructured PP/POE/GP surfaces were worn after a distance length of 3000 mm, they still exhibited superhydrophobic, but high adhesion characteristic, that is, petal effect. The controlled shape‐morphing microarchitectures formed on the microstructured PP/POE/GP surface abraded after 1000 mm, possessing wetting stability during droplet impacting. Highlights: The elongation at break of composites was improved by 2000% through adding POE.The composite microstructure deforms to consume energy during abrasion and POE reinforces this energy dissipation process.POE improves fracture toughness and wetting stability of composites. [ABSTRACT FROM AUTHOR]

Fiber‐reinforced composites have emerged as versatile materials with applications spanning diverse industries, driven by their exceptional mechanical properties and lightweight nature. This review provides a comprehensive overview of natural fiber‐reinforced composites, focusing on their enhanced mechanical and functional properties achieved through modern processing techniques. The study delves into various manufacturing methods, such as thermoforming, additive manufacturing, compression molding, electro‐spinning, pultrusion and autoclave molding, which have significantly contributed to the advancement of these composites. The review further investigates the multifaceted properties of these composites, which highlights the versatility and applicability of these materials and provides a holistic understanding of their potential applications. Additionally, the work addresses current research gaps and identifies prospects, shedding light on the evolving landscape of natural fiber‐reinforced composites. The synthesis of processing techniques, material properties and potential applications offers valuable insights for researchers, practitioners and industries aiming to harness the full potential of these sustainable and high‐performance materials. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study introduces a novel application of composite materials as Lost Circulation Materials (LCM), leveraging their high specific strength, non-abrasiveness, and environmentally friendly profile. A new formulation of Carbon Fiber Reinforced Polymer (CFRP) composites was developed using an advanced twin-screw extrusion process followed by compression molding. Their efficacy in sealing fractures was quantitatively assessed in accordance with American Petroleum Institute (API) standards using a Bridging Material Tester (BMT). Comparative analysis with previous studies on Bagasse Fiber Reinforced Polymer (BFRP) composites was conducted. Interfacial interactions and fracture morphology were examined through Scanning Electron Microscopy (SEM), revealing the CFRP composites' superior resistance to water absorption. The moisture absorption tests indicated that the CFRP absorbed 0.7% moisture after 24 h, compared to 15% for BFRP, suggesting enhanced durability in wet conditions. However, despite their robust mechanical properties, they exhibited lower fracture-sealing efficiency compared to BFRP composites. These findings not only underscore the potential of composite-based LCMs in enhancing drilling safety but also guide future research toward optimizing composite formulations for more effective field applications. [ABSTRACT FROM AUTHOR]

This research proposes a novel sustainable composite using basalt (B), hemp (H) and polyurethane rubber (Pu) reinforced in nano clay functionalised epoxy matrix for sacrificial structural applications prone to low‐velocity impact (LVI). To this end, symmetric and asymmetric laminates such as HHHH, BBBB, BHHB, BHPuHB, BBPuHH and BPuBPuHPuH are fabricated using compression molding techniques and subjected to LVI at three different impact energies of 19.66, 39.39, and 59.05 J. The hemp fibers were treated with NaOH solution before fabrication. Material characterization such as X‐ray diffraction, Raman spectroscopy and morphological studies has been carried out. The impact and post‐impact properties of the proposed composites are experimentally evaluated and validated with the finite element (FE) results. The effect on the residual tensile strength degradation of laminates at different interlayers and energy levels is also investigated using the Caprino analytical model. The barely visible impact damages (BVID) are investigated through non‐destructive dye‐penetration tests, which facilitate easy identification of the prominent LVI damages like "Plateau" and "Cliff‐drop" impressions. Based on the impact energy absorption and residual tensile strength, proposed laminates followed BHPuHB > BBBB > BHHB > HHHH. The experimentation suggests that Polyurethane core laminates support maximum impact energy absorption by favoring a structural change in interlayers. Also, the residual tensile strength decreases as impact velocity increases. Highlights: Low‐velocity impact behavior of sustainable composites is experimented.Basalt, hemp and polyurethane rubber are reinforced in nano clay epoxy matrix.A FE framework to validate the experimentation is proposed.Dye penetrant NDT is adopted to investigate the damages.Morphological studies are conducted to understand LVI responses. [ABSTRACT FROM AUTHOR]

Microinjection molding (μIM) is characterized by high shearing and cooling rates, resulting in higher a degree of filler orientation which impairs the electrical conductivity (σ) of conductive filler‐containing polymer composites when compared with that of compression molding and conventional injection molding processes. In this study, polypropylene/polyamide 6/multiwalled carbon nanotubes (PP/PA6/CNT) composites were used as the model system to investigate how blending sequence, injection speed, and component mass ratios affected the morphology and σ of PP/PA6/CNT microparts. The results demonstrated that CNTs exhibited a higher affinity for the polar PA6 phase and they tended to be preferentially distributed in PA6 domains. The deformation and coalescence of CNT‐rich PA6 phase promoted the creation of an intact and continuous filler network structure along the flow direction under the influence of high shearing conditions in μIM. When the mass ratio of PP:PA6 was 70:30 and the concentration of CNT was 7 wt%, the micropart possessed the highest σ (1.2 × 10−6 S/m) when compared with their PP/CNT (4.4 × 10−9 S/m) and PA6/CNT (3.4 × 10−10 S/m) counterparts. Higher injection speeds resulted in higher degree of CNT orientation, which negatively affected the σ of subsequent moldings. This work established an approach for producing electrically conductive microparts that demonstrate promising applications in the fields of electronics, automotive, and microsystems among others. Highlights: PP/PA6/CNT composites were used as model systems for microinjection molding.The electrical conductivity was improved by shear‐induced deformation of CNT‐rich phase.The properties of PP/PA6/CNT microparts were affected by process parameters. [ABSTRACT FROM AUTHOR]

The escalating environmental concerns surrounding the massive production and improper disposal of non-biodegradable food packaging materials have led to the urgent need for sustainable alternatives. In response to this demand, the present study aims to model a biodegradable food package utilizing abundant agro-wastes, specifically rice husk, plantain stem, and sugarcane bagasse. The primary objective is to develop a packaging material that not only reduces environmental pollution but also utilizes readily available agricultural residues. Various formulations were tested to optimize the proportion of cooking starch, ensuring maximum binding efficiency while maintaining desirable physical and mechanical characteristics of the packaging material. The resulting mixture was then molded into the desired shape using a suitable technique such as compression molding or extrusion. The mechanical properties, such as tensile strength, flexibility, and impact resistance, were assessed to evaluate the performance of the developed packaging material. [ABSTRACT FROM AUTHOR]

Fibers collected from the husk of areca nut trees were chopped to a length of 30 mm and were either used as such or subjected to alkaline treatment by immersion in a 5% sodium hydroxide (NaOH) solution. The untreated and treated fibers were investigated using thermogravimetric analysis (TGA) before the fabrication of composites using an epoxy matrix. Different amounts of fibers were introduced in the matrix, fabricating the composite by compression molding. The composites were subjected to tensile, flexural, and Charpy impact and Shore D hardness testing, which all demonstrated the considerable advantage obtained with the growing quantity of fibers, especially when employing treated fibers, except in the case of hardness, where limited advantages were encountered. Wear tests were carried out on treated fiber composites and the surface morphology of the worn-out samples was studied, which also demonstrated the improvement in fiber-matrix bonding obtained with the growing amount of fibers. The main limitation of the fibers was their low elongation even after treatment. The fibers hardly reached 4%, which might represent a quite normal value for this kind of fibers, possibly due to with tendency to fibrillation. This would somehow compare these composites with others with similar amounts and lengths of natural fibers. [ABSTRACT FROM AUTHOR]

Mechanical, thermal, and water absorption properties of banana fiber and sisal fiber-reinforced epoxy biocomposites were evaluated with and without cashew nut shell (CNS) filler, either separately, or as hybrid biocomposites. Bidirectional woven mats were used to make composites by compression molding. The CNS filler content was 5% to 10%. Adding CNS filler of up to 5% improved the mechanical and thermal properties. Further increases in filler content above the threshold value diminished their mechanical properties due to poor dispersion and increased porosity. The maximum tensile and flexural strength were found as 43 and 92 MPa. The highest impact strength was obtained with the hybrid biocomposites with 5% filler. This was attributed to the toughening effect of phenolic compounds in the CNS. In addition, the thermal stability of the biocomposites was influenced by filler content. The biocomposites exhibited varying water absorption capacities as the filler content increased with the water uptake. Scanning electron microscopy (SEM) images showed the microsurface of the fractured samples and their interfacial bonding, fiber pull-out, and fracture. However, increasing filler content in the biocomposite reduced the filler pull-out and led to fiber breakage. [ABSTRACT FROM AUTHOR]

Polypropylene and ammonium phosphate (AP) composites were synthesized at a 25 wt% concentration. The changes in the morphological, thermal, and physical behavior of the composites were analyzed with the addition of lignosulfonate (LG) and zirconium phosphate (ZrP). Additionally, metallic zirconium was deposited onto lignosulfonate using the magnetron sputtering technique to develop polypropylene and zirconium-modified lignosulfonate (LGMod) composites. Thus, composites of PP/25AP, PP/25AP/8LG/5ZrP, and PP/25AP/8LGMod were synthesized. The synthesis involved mixing the materials in a Hake mixer, followed by compression molding. The composites were characterized by field emission scanning electron microscopy (SEM–EDS), a thermogravimetric analysis (TGA) with combustion parameters, a vertical burn test (UL-94), a thermal camera, and mechanical properties. All composites achieved a V2 rating according to UL-94 standards. The PP/25AP extinguishes flames more quickly compared to other materials, approximately 99.2% faster than PP and showed the lowest temperature variation and mass loss after burning. The PP/25AP/8LG/5ZrP composite exhibited a 7% higher rigidity and 84.5% better flame retardancy compared to pure PP. Additionally, substituting ZrP with LGMod led to a lower environmental impact and improved thermal properties, despite some mechanical disadvantages. [ABSTRACT FROM AUTHOR]

Thermoplastic fiberglass was compression molded in the form of thick panels with a nominal thickness of 10 mm and a size of 300 × 300 mm2. A simplified procedure was adopted to speed up the lamination procedure and adapt it to the aim of recycling waste, glass fibers, fabrics, and thermoplastic films. Low density polyethylene was used as a matrix to simplify the laboratory process, but the same procedure can be extended to other thermoplastic film, such as polyamide. The final thermoplastic composite shows unique properties in terms of its repairability, and its performance was improved by increasing the number of repairing repetitions. For this aim, a repairability test was designed in the bending configuration, and three consecutive cycles of bending/repairing/bending were carried out. The static mechanical properties of the final thermoplastic composite were, conversely, low in comparison with traditional fiberglass because of the choice of a polyethylene matrix. The bending tests showed that the maximum strength was lower than 10 MPa and the elastic modulus was less than 1 GPa. Nevertheless, the toughness of the thermoplastic composite was high, and the samples continued to deform under bending without splitting into two halves. [ABSTRACT FROM AUTHOR]

To manufacture, feature and analyze the potential of materials to be used as raw material for drug delivery systems for the treatment of overactive bladder. Four distinct mixtures of oxybutynin and polymers ethylene vinyl acetate (EVA) and high-density polyethylene (PE) were prepared via compression molding and hot melt extrusion. The materials were characterized regarding their physicochemical and mechanical properties as well as drug release potential. Promising results were obtained in which the release of oxybutynin was observed for more than 250 days from both EVA and HDPE matrices. The obtained data demonstrate it is possible to manufacture HDPE- and EVA-based samples with the incorporation of oxybutynin, and the EVA samples presented an adequate release profile. The results are promising for the development of an intravesical device with drug delivery, especially because super dose risk is extinguished when considering the release from a monolithic release system. [ABSTRACT FROM AUTHOR]

The goal of this study is to determine the effect of varying the volume fraction of a novel ABS–rubber seed husk cellulose 3D-printed honeycomb core on the mechanical, drop load impact, fatigue, and thermal behavior of a sunn hemp polyester skin composite. The cellulose/ABS-tailored filaments were created using a screw extruder and the composites were manufactured using compression molding. The results of the tests showed that the tensile strength, flexural strength, tensile modulus, flexural modulus, and Izod impact were all enhanced by the addition of cellulose and the sunn hemp fiber. Moreover, adding 4.0 phr of cellulose to the ABS matrix increased its tensile strength by 141 MPa, flexural strength by 173 MPa, tensile modulus by 4.9 GPa, flexural modulus by 6.1 GPa, and impact toughness by 5.5 J. Similarly, under 25, 50, and 70% of ultimate stress loading conditions, and the fatigue cycles of the composite RSC5 with cellulose content of 4.0 phr reached up to 26,897, 23,899, and 21,559. However, composite with 2.0 phr of cellulose produced significant energy absorption of 12.4 J in the drop load impact toughness. Similarly, the mass-loss stability of composite RSC5 improved with 4 phr of cellulose. The final decomposition temperature was recorded at a maximum of 532 °C, which is a significant improvement on comparison with other composites. Finally, SEM fractography proves that the ABS core adheres better to the polyester resin and the fibers are well adhered to the matrix. In engineering applications, where lightweight composite panels and boards are required, these high-performance and high-thickness core–skin composites could be utilized. [ABSTRACT FROM AUTHOR]

This study explores the tribological properties of mollusk‐shell‐high‐density polyethylene (MS‐HDPE) biocomposites and diamond‐like carbon (DLC)‐coated metal beads as potential substitutes for hip joint prostheses. HDPE biocomposites with 0, 5, and 10 wt% of MS were developed using hot compression molding. Coatings included pure DLC, DLC‐Si, and DLC W:H. Wear tests on a ball‐on‐disk tribometer examined friction and wear rates against coated and uncoated balls, along with wear morphology. MS‐HDPE demonstrated superior tribological performance against DLC, achieving a 67% reduction in specific wear rate compared to pure HDPE. The study suggests that 5 wt% MS‐HDPE coupled with a DLC‐coated counterpart coating could be a promising combination for orthopedic applications, presenting a potential solution to metal corrosion and wear debris issues in orthopedic implants. Highlights: Tested coatings: DLC, DLC‐Si, and DLC W:H.Biocomposite wear versus coated balls.DLC coating improves wear with shell fillers.Mollusk shell strengthens biocomposites.Reduced wear rate by 63% and friction by 77%. [ABSTRACT FROM AUTHOR]

Metal injection molding of aluminium alloy (MIM-Al) attracts attention, owing to the lightweight, corrosion resistance and good thermal conductivity. However, it is hard to fabricate high-quality MIM-Al due to the hard-to-sinter powder and poor mechanical properties. Here, we report a facile compression molding process for fabricating high-density 7075Al alloy parts using polyformaldehyde (POM)-based feedstock. Pressureless sintering with a high nitrogen flow rate was adopted to promote sintering densification process. The wetting behavior, rheological properties, and morphology of the feedstock were characterized, showcasing the shear-thinning behavior and suitable viscosity for POM-PP-SA binder. Through controlling the compact pressure, mold temperature and holding time, green gear part with good shape retention and dense microstructure was achieved. Influence of process factors and sintering temperature on the microstructure and mechanical properties of 7075Al alloy are investigated. Remarkably, the aluminum alloy components sintered at 610 °C exhibited excellent performance, with a relative density reaching 97.6 % and a tensile strength of 214.8 MPa. This achievement provides a foundation for the industrial application of complex-shaped aluminum alloy components through the compression molding process.

Silver nanowires (AgNWs) have excellent electrical conductivity and nano-sized effects and have been widely used as a high-performance electromagnetic shielding material. However, silver nanowires have poor mechanical properties and are prone to fracture during the preparation of composite materials. In this study, PVDF/rGO/AgNW composites with a segregated structure were prepared using low-pressure compression molding and the AgNW-backfilling process. The low-pressure compression of the composite significantly improves its electromagnetic shielding performance because the low-pressure process can maintain the AgNWs' integrity. The backfilled AgNWs played a vital role in increasing the path of electromagnetic wave propagation and the absorption of electromagnetic waves. The backfilled amount of AgNWs was only 1 wt%, which increased the composite material's conductivity by one order of magnitude. The total electromagnetic interference shielding (SET) of the composite materials increased by 23.3% from 24.88 dB to 30.67 dB. The absorption contribution (SEA/SET) increased from 84.2% to 92.8%, significantly improving the electromagnetic interference shielding and the absorption contribution of the AgNWs in the composites. This was attributed to the backfilling of the porous structure by the AgNWs, which promoted multiple reflections and enhanced the absorption contribution. [ABSTRACT FROM AUTHOR]

The polyphenylene sulfide (PPS) mesh-based polysulfone (PSF)-zirconia (ZrO 2) composite diaphragm represents a new type of high-performance diaphragm for alkaline water electrolysis hydrogen production, offering low area resistance and high chemical stability. In this study, composite diaphragms with excellent performance are prepared using preheated compression molding, phase inversion precipitation, and vacuum stirring degassing techniques. The comprehensive performance of the prepared diaphragm is compared to that of the commercial Zirfon® diaphragm. The results indicate that the prepared composite diaphragm, with a thickness of 140 μm, exhibits excellent performance. Compared to the Zirfon® UTP 220 diaphragm, the ultra-thin composite diaphragm demonstrates a reduction in area resistance from 0.19 Ω cm2 to 0.1 Ω cm2, an increase in bubble point pressure from 2.31 bar to 2.46 bar, and a voltage of 1.84 V at 1000 mA cm−2. The incorporation of the PPS mesh resulted in a substantial improvement in tensile strength. The application of an ultra-thin composite diaphragm based on PPS mesh can significantly enhance the efficiency of hydrogen production via alkaline water electrolysis. [Display omitted] • Hot-pressing, phase inversion, and vacuum stirring degassing techniques are adopted. • Sponge pore structure improves the bubble point pressure of composite diaphragms. • Ultra-thin composite diaphragm with low area resistance and cell voltage. • It can work continuously and stably in a high-intensity electrolysis environment. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) have theoretically ideal properties for bio-based composite applications; however, the incorporation of these materials into polymers is made challenging by the strong binding of water to CNFs and the irreversible agglomeration of CNFs during drying. Previous methods used "contact dewatering", wherein the addition of wood flour (WF) to CNFs facilitated the mechanical removal of water from the system via cold pressing, which showed potential in producing dried CNF fibrils attached to wood fibers for biocomposite applications. In this work, the viability of contact dewatering with poly(lactic) acid (PLA) powder for PLA/CNF composites was evaluated. The energy efficiency of dewatering, preservation of nanoscale CNF morphology, and mechanical properties were examined by mixing wet CNFs with pulverized PLA at various loading levels, pressing water out of the system, and compression molding and shear mixing composites for testing. The most impressive results from this dewatering method were the preservation of micron-to-nanoscale fibers with high aspect ratios in PLA-CNF composites; increased strength and modulus of 1.7% and 4.2%, respectively, compared to neat PLA; equivalent or better properties than spray-dried nanocellulose at similar loading levels; and an 11-194x reduction in drying energy compared to spray-drying CNFs. [ABSTRACT FROM AUTHOR]

High temperature (200-260°C) military composite engine components made of carbon fiber thermoset materials are susceptible to erosion damage. Evidenced by wear seen during operation, erosion protection remains a challenge for composites in the engine air flow path. In this paper, we investigate polyetheretherketone (PEEK), thermoplastic polyimide (TPI), and ceramic fabric (Nextel™) as potential high temperature erosion coatings for thermoset polyimide composite engine components. We evaluate the erosion protection materials for two qualities: (1) co-moldability with thermoset polyimide composite panels, and (2) erosion resistance to a sandblasting test. Autoclave and compression molding were used to test co-moldability with different manufacturing methods. The compression molding process was optimized to reduce surface defects using a pre-imidization step before the erosion protection layer was applied and final cure was completed. Comolded test panels were cut into small coupons for sandblasting. After 60 s of alumina sandblasting PEEK had negligible mass loss, whereas the TPI and ceramic fabric had roughly the same erosion rate as the uncoated polyimide laminate. [ABSTRACT FROM AUTHOR]

Linear low‐density polyethylene (LLDPE) is a polyolefin known for its superior low‐temperature heat seal ability, low‐temperature tolerance, and bag‐tear resistance which are important features for the polymeric packaging sector. In this work, to improve the mechanical properties and expand the range of applications of LLDPE, the microfibrillar clay mineral palygorskite (PAL) was added. However, the use of PAL as a reinforcing agent for polymers depends on its purification process to extract accessory minerals such as calcite, dolomite, and quartz. In addition to this purification process, two surface modifications were used on the purified PAL (PALp) to improve interactions with LLDPE: silanization with aminosilane (PALs) and organophilization by incorporating an organic compound (PALo). The PAL were characterized according to their morphological properties using transmission electron microscopy (TEM), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT‐IR). The films of LLDPE/PAL, with varying levels (1, 3, and 5 wt%) and types of PAL (raw PAL, PALp, PALs, and PALo), were prepared by an extrusion process, and films were prepared by compression molding, without preferred orientation. The films were characterized by rheological analyses, tensile tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and water vapor permeability. Incorporating modified PAL was significant in enhancing the mechanical properties of the nanocomposites. LLDPE/PALs with the addition of 3 wt% PALs showed a 14% increase in elastic modulus (281.08 ± 8.25 MPa) compared to the nanocomposite with 3 wt% of raw PAL (243.43 ± 15.01 MPa). Highlights: The PAL is a clay mineral with a fibrous morphology and has a low cost.The technique to purify PAL is a quick, simple, and inexpensive technique.Comparison between of two technique surface modification of PAL.The effectiveness of modifications of PAL was confirmed in LLDPE films.The surface modification with silanization was more effective. [ABSTRACT FROM AUTHOR]

Highlights Compression molded hybrid laminates have been manufactured by stacking 10 recycled epoxy‐based carbon fiber plies with interlaminar polyamide film of 50 μm thickness. At first, carbon fiber (CF) reinforced composites underwent thermo‐mechanical disassembly to obtain single composite CF plies. These plies, still impregnated with the waste cured resin, have been re‐assembled by interposing one or two sheets of the thermoplastic film in the lamination sequence. Neat laminates have been used for comparison. Samples of size 85 × 30 mm2 have been tested under bending load, and materials repairability has been evaluated under 2 consecutive repairing cycles that have been carried out by applying pressure and heat along the composite failure line. Even though the neat composite showed the best mechanical properties, after the first repairing cycle a drastic drop has been recorded with a reduction of the elastic modulus of 92.4%. On the other hand, the elastic modulus of the hybrid composites has been reduced of only 24% on average. Thermo‐mechanical disassembly is used to recycle epoxy carbon fiber composite. Hybrid laminates are obtained by placing polyamide film between recycled plies. Pressure and heat are applied along the composite failure line for repairing. Hybrid composites repairing is carried out in comparison with neat materials. Repaired hybrid laminates have a higher elastic modulus than neat once. [ABSTRACT FROM AUTHOR]

The design of eco‐friendly active food packaging systems based on biobased polymeric materials is a growing field of research because of the pressing concern for sustainable development. Herein, monolayer ternary thermoplastic films composed of poly(lactic acid) (PLA), gallic acid (GA, 2.5% w/w relative to PLA), and a plasticizer (poly(ethylene glycol) [PEG] or epoxidized linseed oil [ELO], 5.0 and 7.5% w/w relative to PLA) are prepared via melt‐mixing followed by compression molding. The ensuing plasticized and self‐standing PLA/GA films are translucent and have good mechanical properties (Young's modulus ~2 GPa) and welding performance. The incorporation of GA yields films with ultraviolet‐light barrier properties (transmittance below 40%, 200–400 nm), antioxidant capacity (radical scavenging activity above 94%), and antibacterial activity against the methicillin‐resistant strain of Staphylococcus aureus (minimum of 3‐log reduction colony forming units mL−1). These thermoplastic films are easily degradable via enzymatic degradation with proteinase K from Tritirachium album, reaching weight loss values of 100% after 9 days. The films plasticized with PEG present slightly better antibacterial action and enzymatic degradation, whereas those plasticized with ELO exhibit marginally higher surface hydrophobicity and thermal stability. Thus, the combination between PLA and GA yielded biobased films with bioactive properties that have potential for application in active food packaging. [ABSTRACT FROM AUTHOR]

The hemp-reinforced polypropylene composite was produced by the twin-screw extrusion in the presence of polypropylene-graft-maleic anhydride (PP-g-MA) and silane as coupling agents and subsequence by the compression molding. The hemp fiber was obtained by sodium hydroxide treatment prior to the twin-screw extruder. The PP/Hemp composite was analyzed using a universal testing machine, scanning electron microscope, differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared spectroscopy. The mechanical properties of the PP/MA/Hemp demonstrated a better result than that of PP/Si/Hemp in most hemp contents. The SEM images of the PP/MA/Hemp exhibited excellent interfacial bonding in PP/MA/Hemp30 without fiber pullouts. However, the fiber breakage and some fiber pullout with gaps around the fiber of PP/Si/Hemp indicate the poor bonding of the PP matrix. The functional group of the PP/Hemp composite showed the –OH cellulose result peak of the reaction between hemp fibers and polypropylene. [ABSTRACT FROM AUTHOR]

Using the discrete element method to simulate the interaction between growing media and machinery is an effective method to design seedling machinery and improve the precision of facility horticultural operations. In order to further improve the accuracy of the study on the interaction between seedling block-forming machines and growing media, the growing media used in the production of seedling nursery blocks was taken as the research object, and the Plackett–Burman screening test and Box–Behnken test were conducted based on the discrete element method using the EEPA model to conduct the calibration of discrete element parameters of the growing media. Optimization was conducted with an actual repose angle as the target value, and the optimal combination is as follows: the interparticle collision-recovery coefficient is 0.5066, the collision-recovery coefficient between particles and the geometric model is 0.714, the interparticle dynamic-friction coefficient is 0.381, and the tangential stiffness factor is 0.375. Finally, the soil uniaxial closed compression test was conducted with optimized calibration parameters. The relative error between the maximum axial load on the punch and the measured value in the simulation process was 4.23%, which verified the accuracy and reliability of parameter calibration of the growing media and provided support for the simulation of growing media and optimization of seedling nursery block-forming machine. [ABSTRACT FROM AUTHOR]

Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene (UHMWPE) products. Typically, high stretch and shear flow fields are necessary for the formation of shish crystals. In this study, UHMWPE gel films with reserved shish crystals were prepared by gel molding, the structural evolution and properties of UHMWPE films stretched at temperatures of 100, 110, 120 and 130 °C were investigated by in situ small-angle X-ray scattering (SAXS)/ultra-small-angle X-ray scattering (USAXS)/wide-angle X-ray diffraction (WAXD) measurements as well as scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) measurements. Our findings showed that the reserved shish crystals can facilitate the formation and structural evolution of shish-kebab crystals during the hot stretching. Additionally, the reserved shish crystals promote the structural evolution of UHMWPE films to a greater extent when stretched at 120 and 130 °C, compared to 100 and 110 °C, resulting in higher crystallinity, orientation, thermal properties, breaking strength and Young's modulus. Compared to UHMWPE high-entangled films with reserved shish crystals prepared by compression molding, UHMWPE low-entangled films with reserved shish crystals prepared by gel molding are more effective in inducing the formation and evolution of shish-kebab crystals during the hot stretching, resulting in increased breaking strength and Young's modulus. [ABSTRACT FROM AUTHOR]

This study evaluates multimodal imaging for characterizing microstructures in partially impregnated thermoplastic matrix composites made of woven glass fiber and polypropylene. The research quantifies the impregnation degree of fiber bundles within composite plates manufactured through a simplified compression resin transfer molding process. For comparison, a reference plate was produced using compression molding of film stacks. An original surface polishing procedure was introduced to minimize surface defects while polishing partially impregnated samples. Extended-field 2D imaging techniques, including polarized light, fluorescence, and scanning electron microscopies, were used to generate images of the same microstructure at fiber-scale resolutions throughout the plate. Post-processing workflows at the macro-scale involved stitching, rigid registration, and pixel classification of FM and SEM images. Meso-scale workflows focused on 0°-oriented fiber bundles extracted from extended-field images to conduct quantitative analyses of glass fiber and porosity area fractions. A one-way ANOVA analysis confirmed the reliability of the statistical data within the 95% confidence interval. Porosity quantification based on the conducted multimodal approach indicated the sensitivity of the impregnation degree according to the layer distance from the pool of melted polypropylene in the context of simplified-CRTM. The findings underscore the potential of multimodal imaging for quantitative analysis in composite material production. [ABSTRACT FROM AUTHOR]

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractIn the aviation industry lightweight, high-strength materials have replaced metals to lighten vehicles and reduce fuel consumption. Polymer matrix composite materials have thus been chosen because they are highly resistant to oxidation and chemicals, are lightweight compared to metals, and are simple to manufacture. The aim of this study was to increase the compatibility of carbon fiber fabric (CFF) with polyether ether ketone (PEEK) polymer. Meldrum’s acid and nitric acid modified CFFs were assessed using energy dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The PEEK matrix composites reinforced with CFF were produced by a compression molding method. The composites were characterized by tensile strength tests, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). We concluded that the CFF modification improved the compatibility between CFF and PEEK. The enhancement of the tensile properties of the composites was another indication of this modification’s beneficial effects. [ABSTRACT FROM AUTHOR]

This study explores the utilization of Spent Coffee Grounds (SCG), a residual product of the coffee industry, as a microfiller reinforcement in Poly‐3‐hydroxybutyrate‐co‐3‐hydroxyvalerate (PHBV) biopolymer composites at varying concentrations (1%, 3%, 5%, and 7%). Melt compounding via a twin‐screw extruder and subsequent compression molding were employed in the fabrication process. The SCG microfiller, with particle diameters ranging from 1.11 to 1.28 μm, exhibited a significant negative charge (zeta potential: −20 mV). Hydrophobicity increased up to 5% filler concentration, as indicated by higher water contact angles, but diminished at highest concentration likelihood of agglomeration of the spent coffee grounds within the biopolymer matrix. The addition of SCG enhanced overall mechanical properties, particularly at a 5% filler concentration. Field Emission Scanning Electron Microscopy (FE‐SEM) and Atomic Force Microscopy (AFM) confirmed the successful incorporation of SCG microfiller, improving structural characteristics. Schematic drawings illustrated the interphase bonding of microfiller and matrix. However, properties diminished at the highest filler content (7%) due to coffee grounds' agglomeration. Despite this, SCG incorporation enhanced functional properties, making the biopolymer composite a promising material for sustainable packaging and various applications. Highlights: Enhancement of properties of spent coffee grounds in PHBV biocomposites.Characterization of Biocomposites for multifunctional properties.Fracture and 2D analysis of the tensile fractured surface of biocomposites.A promising material for sustainable and biodegradable packaging. [ABSTRACT FROM AUTHOR]

Mulch was prepared using composted sugarcane leaves, with polyvinyl alcohol and cationic starch as adhesives, through compression molding. The study aimed to investigate the effects of different adhesives on the mechanical properties, thermal oxidative degradation performance, and biodegradability of the covering materials. The results indicated that, when the adhesive dosage was consistent, cover material A, which utilized polyvinyl alcohol as the adhesive, exhibited higher tensile strength and elongation at break compared to cover material B, which employed a blend of polyvinyl alcohol and cationic starch. Specifically, at an adhesive dosage of 20%, cover material A achieved a tensile strength of 0.46 MPa and an elongation at break of 7.72%, representing the highest values among all experimental groups. There was minimal disparity in the thermal oxidative degradation performance between materials prepared with either adhesive; however, a higher quantity of adhesive led to decreased biodegradability performance. After being buried in soil for 120 days, the degradation exceeded 40% for both materials, resulting in loss of their original shape and strength properties. In conclusion, while sugarcane leaves-based biodegradable materials demonstrate favorable degradation performance, further enhancements are necessary to improve their mechanical properties. These materials have potential applications as substitutes for plastic mulch. [ABSTRACT FROM AUTHOR]

SiO2f/SiO2 composites were prepared by compression molding and sintering using short-cut quartz fibers as reinforcement. The effects of fiber volume fraction (15%∼35%) on bulk density, apparent porosity, and mechanical and thermal properties of the composites were investigated. The results indicated that the samples with 25% fiber volume fraction had the best comprehensive performance, with an apparent porosity and compressive strength of 36% and 46.3 MPa, respectively. The flexural strength of the samples was 13.9 MPa, which represented a 90% increase compared to the samples without fibers. It was attributed to the occurrence of fiber debonding and fiber pull-out in the porous matrix. Meanwhile, the residual strength ratio of the samples after 20 thermal shocks was 74.8%. In addition, the average coefficient of thermal expansion was 0.95 × 10− 6/℃ at 300 ℃∼700 ℃ and the thermal conductivity was 0.388 W·m− 1·K− 1 at 800 °C. This approach can satisfy the requirements of low cost, fast preparation of SiO2f/SiO2 composites, which offers the prospect of its application in the integration of load-bearing and thermal insulation. [ABSTRACT FROM AUTHOR]

In recent years, solid dosage forms have gained interest in pediatric therapy because they can provide valuable benefits in terms of dose accuracy and stability. Particularly for orodispersible films (ODFs), the literature evidences increased acceptability and dose flexibility. Among the various available technologies for obtaining ODFs, such as solvent casting, hot-melt extrusion, and ink printing technologies, the solvent-free preparation methods exhibit significant advantages. This study investigated Vacuum Compression Molding (VCM) as a solvent-free manufacturing method for the preparation of flexible-dose pediatric orodispersible films. The experimental approach focused on selecting the appropriate plasticizer and ratios of the active pharmaceutical ingredient, diclofenac sodium, followed by the study of their impacts on the mechanical properties, disintegration time, and drug release profile of the ODFs. Additional investigations were performed to obtain insights regarding the solid-state properties. The ODFs obtained by VCM displayed adequate quality in terms of their critical characteristics. Therefore, this proof-of-concept study shows how VCM could be utilized as a standalone method for the production of small-scale ODFs, enabling the customization of doses to meet the individual needs of pediatric patients. [ABSTRACT FROM AUTHOR]

The objective of the study is to develop and characterize biodegradable monolayer and bilayer films using collagen extracted from tilapia skin and scales (Oreochromis sp.) with chitosan in combination with biodegradable polyester; polylactic acid (PLA) or polycaprolactone (PCL). Collagen extraction was conducted with acetic acid (0.5 M). Monolayer films based on collagen and chitosan were formed by the casting process with a solution of chitosan (2% w/w) in 1.5% acetic acid, followed by the addition of skin collagen at concentrations of 0.5%, 1%, or 2% w/w, and dried at 45–50°C. The PLA and PCL films were made by compression molding. The films were characterized according to their appearance, structure, morphology, interaction with water, thermal stability, and mechanical and barrier properties. The results indicated that collagen from tilapia skin and scales yielded 36.5% and 2.57%, respectively. The results showed that adding chitosan increased the tensile strength but decreased the elongation of the films. An improvement in thermal stability was observed by increasing the proportion of collagen or chitosan, and it also influenced water solubility and water vapor permeability. Microscopy showed a crack‐free interface between collagen and chitosan. The color of the films varied depending on the composition, highlighting the influence of chitosan in yellow and reddish tones. The bilayers with PLA had lower water vapor permeability and higher gloss compared to those with PCL. Finally, the developed films showed promising properties for their application in food packaging and promote the use of fishery waste. Practical applications: The study aims to develop and characterize biodegradable monolayer and bilayer films using collagen extracted from tilapia skin and scales (Oreochromis sp.) combined with chitosan and biodegradable polyester such as polylactic acid or polycaprolactone. The practical applications of this research span a wide range of industrial fields. For instance, monolayer films could be used as sustainable food packaging, offering enhanced barrier properties and biodegradability, thus reducing the environmental impact of conventional packaging. Furthermore, bilayer films could find applications in the healthcare industry, such as controlled‐release drug patches or dressings leveraging the antimicrobial properties of chitosan. This research also provides valuable insights into improving the mechanical, thermal, and barrier properties of biodegradable films, potentially leading to the production of more efficient and versatile materials for a variety of industrial applications. [ABSTRACT FROM AUTHOR]

Post-consumer PET (rPET) has become a worldwide concern due to the huge waste accumulation. Therefore, it is necessary to explore processing methods to recycle or reuse rPET to save resources and contribute to solving environment-related issues. Furthermore, the addition of inclusion complexes in the rPET matrix increases its application in terms of the release of active compounds that improve the added value of the polymer. Thus, active rPET films with thyme and orange essential oils were prepared by compression molding or extrusion. The effect of the different processing methods, as well as reprocessing, on the structural, mechanical, and antifungal properties of the active films was assessed. The results show that compression molding is not a suitable method to produce active films since their operation conditions, such as residence time and temperature, triggered the decomposition of the inclusion complex (IC), negatively affecting the appearance and mechanical properties (brittle and fragile) of films. Conversely, the extrusion process allowed preserving the IC and dispersing them adequately within the rPET matrix, maintaining the mechanical integrity of the films and resulting in a high antifungal activity against the growth of Penicillium funiculosum hyphae. This behavior was also observed after the re-extrusion process, corroborating that extrusion is a suitable method to process the active rPET films more than once without the detriment of their mechanical and antifungal properties. [ABSTRACT FROM AUTHOR]

This research explores the effects of moisture absorption on the mechanical and vibrational performance of Kevlar-basalt/epoxy laminates, which are significant for their strength-to-weight ratio yet susceptible to hygrothermal aging. The quasi-isotropic orientation of [0°/45°/90°/45°/0°] was selected with three Kevlar (0° and 90° orientation) and two basalt (45° orientation) layers. The fabricated laminates were subjected to ageing environments viz., ambient temperature ageing (ATA) and cold temperature ageing (CTA) by immersing in water for a period of six months. The specimens saturated with moisture were analyzed for mechanical and vibrational tests such as tensile, 3-point bending, Charpy impact and impact hammer tests to understand the post ageing behavior of the laminates. ATA and CTA specimens absorbed 4.52% and 3.21% moisture, respectively at saturation. ATA specimens experienced the largest tensile strength reduction of 28.64%, while CTA specimens declined by 14.84%. Flexural strengths decreased by 17.52% for ATA and 7.66% for CTA. CTA specimens retained the highest impact strength at 80.39%, followed by ATA at 75.44%. Increased moisture content led to a higher damping ratio and lower natural frequency, with ATA specimens showing more matrix deterioration, fiber-matrix interface weakening, and delamination than CTA specimens.

The consumption of eggshell powder (ES) as an affluent source of calcium carbonate (CaCO3) can efficiently solve both ecological and financial interest. The use of eggshell waste in eco-composite materials (ECPCMs) is an attempt to reduce waste's negative effects. Eco-composite powders of polyethylene glycol (PEG) and calcium carbonate (CaCO3) were obtained by mechanical grinding. Compression molding was used to produce plates from the ground powders. FTIR spectroscopy and X-ray diffraction analysis showed that the ECPCMs were physically combined and the crystallinity of the two components was affected. According to TGA, the thermal stability of ECPCMs was improved, thanks to the use of eggshell waste powder. On the other hand, the results of the DSC showed that ECPCM with the addition of 90 wt% of PEG in the mixture provides excellent thermal stability and high energy storage density. In light of its high latent heat storage capacity of 156.1 J/g as well as its ability to prevent PEG exudation. Significant enhancement in melting-solidification time shows an improvement in Thermal Energy Storage (TES) response time by adding ES to the PCM. The obtained results indicate a good potential for industrially applied ECPCMs.