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Modern industrialisation and the need for low-density material initiated the up-gradation of material for the necessity of sustainability, and the same goes for engineering materials as well. Right from ancient times, composites have an important place in the field of engineering materials, but now demand for such materials, especially fibre-reinforced polymer (FRP) composites, proliferates just to improve the quality of materials as well as the quality of life. The present work provides a comprehensive literature review on hybrid FRP composites, techniques involved in its fabrication, machining and variation in mechanical properties due to hybridisation. The main focused fibre-reinforced composite are glass fibre, carbon fibre, basalt fibre and Kevlar fibre-reinforced polymeric composites. The paper includes recent work that showcases the hybridisation behaviour and their field of application. [ABSTRACT FROM AUTHOR]

New modified electrode materials, based on a combination of hybrid nanocomposites such as magnetic nanoparticles, inorganic polymer (SiO2) and different types of organic polymers, were studied. Three types of organic polymers were used in order to find the effect that each of polymers has on the electrochemical properties of the final material. The electrochemical properties of the synthesised materials were investigated, the best electrochemical response was for pAAc covered nanoparticles compared to the other three tested materials. This favourable electrochemical response effect is due to the fact that in case of this material we succeed in obtaining a very uniform coverage of the polymeric shell with a favourable hydrogel structure and thicknesses which is perfectly suitable for adsorption of a relatively high concentration of TB in a very easi and homogenous way. By electrochemical measurements it was proved that this electrode presents electro-catalytic effect towards nitrite oxidation and can be used for nitrite detection. By comparing with other electrodes, the electro-catalytic effect of MNPs-SiO2-pAAc is better because the nitrite oxidation peak appears in this case at a potential closer to 0 mV vs. Ag/AgCl/KClsat, which is favourable to avoid interferences in amperometric nitrite detection in real samples. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) is a conductive polymer easily converted into a conducting state. However, its limited mechanical properties have generated interest in fabricating PANI composites with other polymeric materials. In this study, a PANI–prevulcanized latex composite film was synthesized and fabricated in two phases following chronological steps. The first phase determined the following optimum parameters for synthesizing nanosized PANI, which were as follows: an initial molar ratio of 1, a stirring speed of 600 rpm, a synthesis temperature of 25 °C, purification via filtration, and washing using dopant acid, acetone, and distilled water. The use of a nonionic surfactant, Triton X-100, at 0.1% concentration favored PANI formation in a smaller particle size of approximately 600 nm and good dispersibility over seven days of observation compared to the use of anionic sodium dodecyl sulfate. Ultraviolet–visible spectroscopy (UV-Vis) showed that the PANI synthesized using a surfactant was in the emeraldine base form, as the washing process tends to decrease the doping level in the PANI backbone. Our scanning electron microscopy analysis showed that the optimized synthesis parameters produced colloidal PANI with an average particle size of 695 nm. This higher aspect ratio explained the higher conductivity of nanosized PANI compared to micron-sized PANI. Following the chronological steps to determine the optimal parameters produced a nanosized PANI powder. The nanosized PANI had higher conductivity than the micron-sized PANI because of its higher aspect ratio. When PANI is synthesized in smaller particle sizes, it has higher conductivity. Atomic force microscopy analysis showed that the current flow is higher across a 5 µm2 scanned area of nanosized PANI because it has a larger surface area. Thus, more sites for the current to flow through were present on the nanosized PANI particles. [ABSTRACT FROM AUTHOR]

Polylactic acid has found its way into innovative engineering application in aerospace, defense and drone technologies through its unique characteristics such as high strength, low density and easy availability. Carbon fiber reinforced polylactic acid are polymeric composites with polylactic acid as base matrix that has distinctive properties such as extreme durability and high strength to weight. Fused filament fabrication is a type of additive manufacturing technique that comes under material extrusion. Multi material is an engineering concept that enables fabrication of structure that has varying functional properties along a certain direction. This engineering material combines the seemingly incompatible properties of two different material. The aim of this study is to provide insight on the mechanical behavior of multi material wall manufactured through fused filament fabrication. The coupons were prepared and tested in accordance with American society for testing and materials standards. The mechanical tests revealed that multi material possess better mechanical properties than polylactic acid and was on par with carbon fiber reinforced polylactic acid. The images from optical microscope was used to analyse bonding, buckling and fracture morphologies. These results would provide idea such that this multi material could either replace existing material or have its own new application. [ABSTRACT FROM AUTHOR]

The influences of variable damages (crack and delamination) and high-strain loading conditions on the elasto-plastic stress–strain characteristics of fiber-reinforced polymeric composite have been evaluated in this research. The desired constitutive behaviour is obtained using the advent of material modelling features of a unanimously accepted commercial finite element (FE) tool (ABAQUS). The effect of damages (individual/combined) is obtained through a Quad element to analyze different specimens considering various strain rate loading (0.001, 0.01, 0.1, 1, 10, 50). The model validity has been established initially by verifying the outcomes (stress–strain data) with those of the open domain results. Furthermore, the relevant mechanical forces and stress–strain characteristics are computed for several new cases of polymeric composite samples by varying the geometry, damages, and testing conditions (strain-rate loading). Additionally, the sensitivity analysis is carried out based on surrogate models (i.e., stochastic constitutive models) to quantify the influence of damages in presence of strain rate. The comprehensive features and the model capabilities are summarized in detail for the variable geometrical configurations. [ABSTRACT FROM AUTHOR]

Background: Green composites, or Natural Fiber-Reinforced Polymer Composites, have emerged as promising alternatives to synthetic polymers due to their biodegradability, renewability, ease of processing, low density, cost, and energy consumption. Natural fibers are created from plants, animals, and minerals, offering higher structural advantages and better performance due to higher cellulose content and microfibril arrangement. The goal of this research is to evaluate the feasibility of using Acacia tortilis bark and Aerva javanica flowers (natural visible fibers) as a composite by extracting and characterizing their chemical composition and physical characteristics. Methods: The experiments have been done using standard methods using gravimetrical analysis and calculations. Results: The initial phase of our studies has shown that Acacia tortilis fibers can have competitive chemical composition and tensile properties compared to common natural fibers as well as Aerva javanica, is lighter, less dense, and has promising possibilities for utilizing its fiber in developing green composites. Conclusion: The preliminary findings indicate that Acacia tortilis fibers show competitive properties, surpassing common natural fibers and Aerva javanica, making them a promising candidate for green composite development. However, further extensive research is required for conclusive insights. [ABSTRACT FROM AUTHOR]

Among several approaches that utilized for surface modification of polymeric composites; cold/NTP technology has been blossomed into an effectual, facile and economical methodology. In this study, Cs/Gel composites were treated in DBD atmospheric plasma under a He and O2 atmosphere to improve a variety of surface attributes, including surface wettability, tensile strength, topographical alterations, and numerous biological applications. The composites showed enhanced hydrophilicity (lower water uptake capacity) in comparison to untreated composite. Also some topographical changes and the enhanced stability were observed after plasma treatment. Presence of highly reactive species or radicals (Observed using optical emission spectroscopy: OES) were responsible for the etching of the composites. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) results revealed a high thermal denaturation temperature of the scaffold (30–700°C). Amoxicillin drug release was also studied which significantly prolonged for the plasma treated Cs/Gel composite. The CG@He + O2 composite was found to be the best for achieving delivery of amoxicillin drug for stomach infection. The hydrogels displayed good antibacterial features against Enterobacter and Bacillus where better inhibition was found in case of He + O2. The hydrogels were found to be remarkably biodegradable and pH sensitive. It concludes non-thermal plasma treated Cs/Gel hydrogels can be explored for diverse biomedical applications, drug delivery and also in food packaging industry. [ABSTRACT FROM AUTHOR]

Polymeric composites with the hybrid filler network for high-performance electromagnetic interference (EMI) shielding brought increasing interest. Herein, UHMWPE/ground tire rubber (GTR)/conductive carbon black (CCB) (UGC) composites with a hybrid segregated structural CCB-GTR were constructed by solid-phase shear milling (S3M), mechanical blending, and compacted molding processes. The percolation behavior of electrical conductivity and EMI shielding effectiveness (SE) of composites was described using Sigmoidal/Growth models, and its EMI shielding mechanism was discussed. Results showed that the EMI SE of U30G70C20, U50G50C20, and U70G30C20 composites were found to be 37.5, 41.7, and 43.8 dB, respectively, due to constructing a hybrid network. The attenuation rate of microwave radiation is above 99.99%, and the shielding mechanism is mainly electrical loss. Moreover, the relationship between electrical conductivity and EMI SE is consistent with Sigmoidal/Growth models, indicating that Sigmoidal/Growth models can successfully predict the percolation threshold of the EMI SE of UGC composites. [ABSTRACT FROM AUTHOR]

In recent years, the adhesive bonding method has gained increased attention, especially in the automotive industry, for constructing efficient body structures from dissimilar and lightweight materials such as aluminum and polymeric composites. Adhesively bonded automotive structures endure complicated loading conditions, including tensile and bending loading, during their service lives. To the best of the authors' knowledge, there is no published work on the assessment of bending strength in single-lap adhesive joints (SLJs) when considering dissimilar adherends under three-point bending. In this study, three-point bend experiments were carried on the bending strength and the failure mechanisms of dissimilar SLJs made of carbon-fiber-reinforced polymer (CFRP) and aluminum substrates bonded with Araldite 2015 adhesive. Additional experiments were conducted individually on similar SLJs, including aluminum/aluminum and CFRP/CFRP, to investigate and compare the effects of adherend material type on the bending strength and failure behavior of SLJs. The results indicate that a CFRP/CFRP single-lap adhesive joint exhibits significantly higher joint strength in comparison to an aluminum/aluminum single-lap adhesive joint under three-point bending. The strength of dissimilar CFRP/aluminum single-lap joints usually falls between that of an aluminum/aluminum and that of a CFRP/CFRP single-lap adhesive joint. When the CFRP adherend is situated at the bottom of the joint in three-point bending, it imparts significantly greater joint strength and deformation compared to situations where the aluminum adherend is placed at the bottom. [ABSTRACT FROM AUTHOR]

The present study aimed to fabricate a novel polymeric spongy composite to enhance skin regeneration composed of Nystatin (antifungal agent) and Silver Nanoparticles (AgNps). Different formulations (F1–F8) were developed & characterized by using various analytical techniques. AgNps synthesized by chemical reduction method showed spherical morphology 2 µm in size showed by SEM and XRD. A fine porous structure of gel embedded with AgNps having an amorphous structure with 10 % crystallinity due to AgNps was found. IR spectra revealed no chemical interaction between polymers and Nystatin. An increase in thermal stability of formulation was observed till 700 ℃ analyzed by Differential Scanning Calorimetry. Cytotoxic analysis on L929 mouse skin fibroblast cells showed a decrease in cell viability as Ag concentration increased (inactivating Fibroblast and keratinocytes) while 10 mg composition was found safest concentration (94%). Optimized formulation (F2) presented in-vitro drug release up to 90.59% ± 0.76 at pH 7.4, swelling studies (87.5% ± 0.57), water retention (26.60 ± 0.34), pH (5.31 ± 0.03). In the animal burn model, the group that received CHG/Ag/Nystatin healed the wound significantly (p < 0.05). These results suggested that optimized carrier can be used for other anti-fungal drugs facilitating the early healing of the wound. [ABSTRACT FROM AUTHOR]

Abdominal hernias are common issues in the clinical setting, burdening millions of patients worldwide. Associated with pain, decreased quality of life, and severe potential complications, abdominal wall hernias should be treated as soon as possible. Whether an open repair or laparoscopic surgical approach is tackled, mesh reinforcement is generally required to ensure a durable hernia repair. Over the years, numerous mesh products have been made available on the market and in clinical settings, yet each of the currently used meshes presents certain limitations that reflect on treatment outcomes. Thus, mesh development is still ongoing, and emerging solutions have reached various testing stages. In this regard, this paper aims to establish an up-to-date framework on abdominal meshes, briefly overviewing currently available solutions for hernia repair and discussing in detail the most recent advances in the field. Particularly, there are presented the developments in lightweight materials, meshes with improved attachment, antimicrobial fabrics, composite and hybrid textiles, and performant mesh designs, followed by a systematic review of recently completed clinical trials. [ABSTRACT FROM AUTHOR]

Microencapsulated phase change materials (MPCMs) are usually subjected to internal pressure caused by core volume changes or external mechanical stress during service. It is of great importance for individual microcapsule to achieve good mechanical performance to be effective in avoiding the leakage of core material and providing crucial protection to environment. Here, n-octadecane was selected as core material and different amounts of titanium dioxide (TiO2) nanoparticles were added into the melamine formaldehyde (MF) shell, forming n-octadecane@MF-TiO2 hybrid shell MPCMs by in situ polymerization. It has been confirmed that TiO2 nanoparticles had been well embedded in the network structure of MF shell. The doping of TiO2 is beneficial to the inhibition of supercooling and the improvement of the thermal stability for hybrid shell microcapsules. Microcompression tests were conducted to determine the rupture loads of prepared microcapsules. TiO2 nanoreinforcements increase the rupture loads of MF-TiO2 shell microcapsules and the improvement percentage in rupture load reaches a maximum of 138.14% at TiO2 content of 2 wt.% compared with pristine microcapsules. Crack deflection and pinning may account for the potential strengthening mechanism of the MF nanocomposites. The reinforced MPCMs will contribute to their more promising and widespread applications in thermal energy storage systems. [ABSTRACT FROM AUTHOR]

Background: Most food packaging materials are non‐biodegradable and do not protect against microbial growth. In the present study, we have synthesized and characterized environmentally friendly packaging material using nanotechnology. Objective: Cascabela thevetia incorporated zinc nanoparticles and PVP/KC blended films of various ratios were synthesized using the solvent casting method. The nanoparticles were tested for their physical and chemical properties. The antimicrobial activity of films and an in vivo toxicity studies were performed using Drosophila as a model system. Results: The thickness of blend films increases as the concentration of nanoparticles is enhanced. The UV–visible spectra of prepared ZnO nanoparticles exhibited maximum absorbance wavelength (λmax) at 360–380 nm. The nanocomposite films' TS and EB and Y were also increased. Scanning electron microscopy (SEM) analysis suggested that all the films were homogenous, crack‐free, and possessed continuous bubble‐free surfaces. FT‐IR results showed chemical interaction between PVP/KC and Zinc oxide nanoparticles. Fifth sample showed greater antibacterial activity. A toxicity study showed that the flies survived >92% in all the samples up to 10 days of continuous feeding, which signifies that the material has low toxicity. Conclusion: Nanocomposite films can be used as antimicrobial food packaging material to enhance the shelf‐life of food. [ABSTRACT FROM AUTHOR]

Thermally conductive polymeric composites are promising for heat management in microelectronic devices. This work presents a binary‐hybrid composite of boron nitride (BN) nanoparticles and micro‐diamond (D) fillers in an elastomeric polyurethane (PU) matrix which can be three‐ dimensionally printed to produce a highly flexible and self‐supporting structure. The research shows that a combination of 16.7 wt% BN and 16.7 wt% D results in a robust network within the polymer matrix to improve the tensile modulus more than nine times with respect to neat PU. Significantly, the hybrid matrix enhances the thermal conductivity by more than two times when compared to neat PU. The enhancement in mechanical, and thermal features make this three‐dimensional printable multiscale hybrid composite suitable for flexible and stretchable microelectronic applications. [ABSTRACT FROM AUTHOR]

A promising graphene polymeric composite was synthesized using gamma irradiation of reduced graphene oxide (RGO); itaconic acid (IA) grafted starch (St) and 16, 16-dimethylheptadecan-1-amine (PJMT). The prepared composite (HGPC) and RGO were characterized using different analytical methods such as FT-IR, SEM, DTA-TGA, XRD, particle size distribution, and pore size distribution. Then after, they were assessed as sorbents for removal of europium radionuclides from aqueous solutions at pH 3, volume-to-mass ratio 0.1 L g−1 and 25 °C. The sorption reaction reached the equilibrium after 4 h. The Qmax attained the values of 106.79 and 11.46 mg g−1 for Eu(III) sorption onto HGPC and RGO, respectively. The values of the isotherm parameters confirmed that a chemisorption mechanism controlled the sorption process. The calculated thermodynamic parameters demonstrated that the sorption of Eu(III) by HGPC was a spontaneous and endothermic process. 83.53% and 84.09% of europium radionuclides were effectively eluted from loaded materials using 0.1 M EDTA and 0.1 M HCl solutions, respectively. [ABSTRACT FROM AUTHOR]

The development of polymeric composites that possess both exceptional electromagnetic interference shielding effectiveness (EMI SE) and high absorption capacity has always been appealing, yet it continues to pose a significant challenge. To this end, we disclose a hollow and spherical shielding unit that could achieve "absorption‐reflection‐attenuation" process for incident electromagnetic (EM) wave, which was fabricated through decorating Ni nanoparticles onto rGO hollow microspheres by virtue of Pickering emulsification method followed by thermal annealing. With integrated magnetic and electric parts, the consequent shielding composite by assembling these microspheres into PDMS displayed not only a favorable EMI SE of 44 dB across the entire x‐band, but also significantly improved absorption performance that has exceeded 95% of the total SE. Moreover, the power coefficient of absorption (A) is up to 0.73 at the pyrolysis temperature of 550°C. Such admirable performance is mainly attributed to the synergistic effect of conductive rGO walls, magnetic Ni nanoparticles, as well as the unique spherical architecture, which has enabled more efficient capture and attenuation of EM waves. Herein, this research has highlighted the development of polymeric composites for high‐performance EMI shielding applications. Highlights: Reflection‐absorption‐integrated shielding compartment was designed.Decorating magnetic Ni nanoparticles onto rGO hollow microspheres.High EMI SE with enhanced absorption ability was acquired.Unique structure generating synergistic effect on EMI shielding [ABSTRACT FROM AUTHOR]

Self-healing polymers have received widespread attention due to their ability to repair damage autonomously and increase material stability, reliability, and economy. However, the processability of self-healing materials has yet to be studied, limiting the application of rich self-healing mechanisms. Additive manufacturing effectively improves the shortcomings of conventional processing while increasing production speed, accuracy, and complexity, offering great promise for self-healing polymer applications. This article summarizes the current self-healing mechanisms of self-healing polymers and their corresponding additive manufacturing methods, and provides an outlook on future developments in the field. [ABSTRACT FROM AUTHOR]

Four novel phthalonitrile-capped polyarylene ether nitrile oligomers containing trifluoromethyl groups (FPEN-Ph) with different molecular weight were designed and synthesized by adjusting the ratio of bisphenol AF (BPAF) and 2,6-dicholorobenzonitrile (DCBN). The molecular structure of FPEN-Ph oligomers were characterized and analyzed by FTIR, 1HNMR and Gel permeation chromatography. Their curing behaviors were studied by Differential scanning calorimetry and rheological tests, and curing kinetics were also discussed by gel method in detail. The glass fiber cloth reinforced FPEN-Ph composites (FPEN-Ph/GF) had flexural strengths of 415.9–497.5 MPa, shear strengths of 34.5–50.5 MPa, and glass transition temperatures (T gs) in the range of 211.3°C–416.6°C. The initial thermal decomposition temperatures (T 5%) of various FPEN-Ph cured products were higher than 500°C under nitrogen. Meanwhile, Fracture morphologies showed that the GF/FPEN-Ph composites had excellent interfacial adhesion between FPEN-Ph matrix and GF reinforcement. Herein, the FPEN-Ph resin could be a good candidate for high-performance polymeric composites and the advanced FPEN-Ph/GF composites can be used under high temperature environment. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymeric composites have long been of interest owing to their remarkable properties of high strength, toughness, and low weight. Part of their appeal comes from their customizability to fulfil a large number of applications. Controlling the degree of interfacial adhesion between fibers and polymeric matrix is one of the important ways of optimizing composite properties for desired applications. The present study examines a simple technique for modulating adhesion, its measurement using single-fiber fragmentation, and its effects on the tensile, flexural, and impact properties of the corresponding fiber tow composites. Adhesion was modified by coating untreated Hexcel IM7 fibers to various levels with room temperature 'vulcanizing' silicone dissolved in the mixed alkane solvent IsoparTM L. The matrix polymer was Epon862 with an Epikure curing agent W. Fiber tows consisted of 12k fibers, and were tensile, 3-point bend and 'charpy' impact tested to evaluate their mechanical properties. Interfacial adhesion was reduced from 101 MPa to near zero, while impact toughness was more than doubled. The tensile modulus decreased only up to 25%, while the flexural modulus decreased by approximately 50%. Ultimate flexural strength and flexural modulus decreased. Energy to failure had no meaningful changes. [ABSTRACT FROM AUTHOR]

Sargassum is a type of marine algae that has caused environmental problems in Mexico because it arrives in high quantities along the Mexican coast, especially in the Mexican Caribbean. This situation has become an environmental and economic problem, impacting tourism and other activities. As a result, it is reasonable to try to find an application for these algae. Recently, some applications in civil construction, cosmetics, and the food industry, among others, have been reported. The present work evaluates the thermal and structural properties of new polypropylene (PP)–Sargassum-based composites. Also, the effect of adding calcium stearate (CS) to increase the interaction between PP and Sargassum particles was investigated. PP–Sargassum particle composites were prepared by a melt mixing process, and the properties of these composites were evaluated using thermal techniques such as dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and infrared spectroscopy (FTIR). The DMA results showed that composites with low concentrations of Sargassum particles perform better than those with higher concentrations. When CS was added to composites, there was a significant improvement in storage modulus compared with composites without CS. This was attributed to the good adhesion of the particles to the matrix because the mobility of macromolecules increased in the presence of CS. The thermal stability of PP–Sargassum particle composites decreases when the amount of particles increases, and the addition of CS does not positively affect the thermal behavior of composites. The findings open the possibility of using Sargassum particles in new applications of these algae as a polymer additive to generate sustainable materials. [ABSTRACT FROM AUTHOR]

A wide variety of human and veterinary pharmaceuticals have been frequently found in the aquatic environment around the world. Among those, non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, anti-hypertensives, and anti-depressants are the pharmaceuticals that are most frequently detected in aquatic systems. According to many research, the indirect exposure of living organisms to pharmaceuticals through aquatic systems could cause severe ecological and toxicological effects. Various conventional treatments, such as physical, chemical, and biological treatments, have been investigated for the removal of pharmaceuticals from water. However, the efficiency of these processes is often low, indicating the necessity of developing new and more modern ones. The use of polymeric composite materials in processes such as adsorption and photocatalysis has lately attracted significant attention due to their unique features and capacity to degrade and remove a variety of organic contaminants, including pharmaceuticals. Therefore, this review article summarizes the occurrence of commonly used pharmaceuticals in water reservoirs and their removal by adsorption and photodegradation using eco-friendly polymer-based composites, such as alginate-based, chitosan-based, cellulose-based, gelatin-based, and lignin-based composites. Along this line, the impact of adsorbent/photocatalyst amount, pH, pharmaceutical concentration, removal efficiency, etc. is also briefly discussed. [ABSTRACT FROM AUTHOR]

An accurate and simple screening method has been developed for the determination of fluoroquinolone antibiotics. Carbon dots were synthesized by simple hydrothermal treatment as highly fluorescent nano-sensors. They were subsequently used in the synthesis of organic-based molecularly imprinted polymers to develop fluorescence-based polymeric composites using enoxacin as a representative dummy template molecule of fluoroquinolones. The method was optimized concerning the pH of the medium and composite concentration. The normalized fluorescence intensity showed efficient quenching under optimized conditions upon successive addition of the template, with an excellent correlation coefficient. The proposed method was applied to eight other fluoroquinolones, exhibiting, in all cases, good correlation coefficients (0.65–0.992) within the same linearity range (0.03–2.60 mg mL−1). Excellent detection and quantification limits were been obtained for the target analytes down to 0.062 and 0.186 mg L−1, respectively. All studied analytes showed no interference with enrofloxacin, the most commonly used veterinary fluoroquinolone, with a percentage of cross-reactivity varying from 89.00 to 540.00%. This method was applied successfully for the determination of enrofloxacin in three different types of meat samples: beef, pork, and chicken, with good recoveries varying from 70 to 100% at three levels. This new procedure is an easy analytical method that can be useful as a screening method for monitoring the environmental hazard of fluoroquinolones in quality control laboratories. [ABSTRACT FROM AUTHOR]

Thermal interface materials (TIMs) with good thermal conductivity are paramount in mitigating the heat concentration challenges encountered during the operation of highly integrated components in sophisticated electronic devices. To optimize the comprehensive performance of TIMs, a balance must be struck: minimizing the filler concentration to attenuate materials hardness while maximizing filler content to bolster the thermal conduction pathway. Drawing inspiration from the orientation of tree branches passing through steppingstones in river, a method was proposed in this study. This method exploits the shear effect of carbon fiber (CF), owing to viscosity variances during diameter extrusion, and the differential flow velocity between CF and alumina to induce a significant degree of orientation. Combined with subsequent flipping and bonding, a TIM with vertically oriented CF was prepared. The TIM was obtained with a mere 12.1 wt% CF incorporation, the composite exhibits a through-plane thermal conductivity of 21.29 W/(m·K), representing an enhancement of two orders of magnitude relative to pristine silicone rubber, while retaining its flexibility and deformability. The orientation degree and high efficiency orientation effect of CF have been characterized via scanning electron microscopy (SEM), thermal conductivity test and light-emitting diode (LED) temperature rise test. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF) reinforced epoxy (EP) matrix composite was widely used in industries, however, the mismatch of modulus between CFs and resin would lead to easy damage at the composite interface. In addition, complex modification methods limited the application of CF composite. To address these problems, a simple and efficient physical coating method was used to introduce a degressive gradient modulus layer on the CF surface. The "stepped modulus" structure could effectively disperse stress, improve the mechanical interlocking and wettability, and realize the modulus matching between fiber and resin, thus significantly improving the interface properties of the composites. The interfacial properties of Cn‐CNT‐CF/EP (n was the number of coatings) were gradually improved with the controllable gradient modulus layer established. The interlaminar shear strength (ILSS) and transverse fiber bundle (TFB) strength of C4‐CNTs‐CF/EP were increased by 65.7% and 85.6%, respectively. Due to the presence of a "degressive gradient" modulus layer, the improved mechanical properties of the Cn‐CNT‐CF/EP were comparable to or even more significant than other complicated approaches found in the literature. This simple and effective composite interface construction technique laid the theoretical and practical foundation for the preparation of high‐performance CF composite. [ABSTRACT FROM AUTHOR]

In this work, investigated the mechanical properties and microstructure of Ground Tyre Rubber (GTR) i.e. polymeric waste blended with Natural Rubber (NR), Butadiene Rubber (BR), and Styrene-Butadiene Rubber (SBR) composites. A two-roll mill and hydraulic press were used to create NR (70 parts per hundred of rubber (phr)) composites with 25 phr of BR and 5 phr of SBR and various proportions of GTR (0, 10, 20, 30, and 40 phr). With the incorporation of Nylon 6 (Ny 6) at 5 phr, the interfacial adhesion of NR/BR/SBR composites was improved. NR-based hybrid composites with mechanical and curing properties were enhanced and compared with pure NR. It was noted that the maximum tensile strength, tear strength, and hardness were enhanced by 77.74%, 17.9%, and 36.4% in NR/BR/SBR/GTR (70/25/5/40) over pure NR. The elongation at break was decreased by 54.55%, while young's modulus was enhanced in NR/BR/SBR/GTR (70/25/5/40) over pure NR. With the incorporation of 40 phr of GTR in the NR/BR/SBR composites, cure properties like scorch time (tS2) and cure time (tC90) were reduced by 53.97% and 65.71%, while the minimum torque (ML) and maximum torque (MH) were enriched by 13.35% and 12%, respectively, when compared with the pure NR. Based on the Scanning Electron Microscope (SEM) and Thermogravimetric Analysis (TGA), GTR particles were uniformly distributed, and the thermal stability was enhanced by 25.40% in NR/BR/SBR/GTR (70/25/5/40) composites over pure NR. The absorption bands of NR, BR, SBR, and GTR elements in the developed hybrid composite were identified by Fourier transform infrared. The glass transition temperature (Tg) was diminished from -58.17°C to -63.42°C. With the inclusion of 40 phr of GTR in the NR/BR/SBR composite. Finally, it was recommended that the incorporation of 40 phr of GTR is suitable for NR/BR/SBR composites. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) has been found to be a powerful method for non-destructive testing of glass-fiber reinforced polymeric composites. Various authors have investigated the use of OCT in offline lab-scale detection of fiber orientation and defects in thermoset-based composites. This work evaluated the potential of OCT as a technique for detecting common defects in the continuous production of thermoplastic glass-fiber reinforced unidirectional (UD) tapes. Measurements were first conducted with a stationary OCT sensor using a spectral domain system to investigate: (1) insufficiently impregnated fiber regions, (2) unfilled gaps, (3) polymer accumulations causing fiber/matrix irregularities, and (4) rough tape surfaces. Optical microscopic analysis was used for validation. To overcome the limited maximum field of view of modern OCT setups, we then developed a novel inline test rig to accurately simulate process conditions and measure across the whole tape width. We show that OCT is a reliable method for acquiring cross-section information on tape quality both at the lab scale with a stationary sensor and inline with a sensor moving across the tape surface. Our OCT measurements were in excellent agreement with our offline microscopic investigations. OCT is a powerful, non-destructive and high-resolution method for quality assessment of glass-fiber reinforced UD tapes and has great potential for use in inline quality assurance systems. [ABSTRACT FROM AUTHOR]

In the present work polymeric composite films materials based on polyvinyl alcohol (PVA), glycerol and silver nitrate the conducted composites with high mechanical characteristics were created. In the process of composites drying, glycerol acts as a reducing agent and the formation of silver nanoparticles occurs, moreover the reducing take places at room temperature. The AgNO3 content is varied from 0.01 to 30 wt.%. Taking into account the physical-mechanical and conducting properties of composites, it is established that the optimum content of glycerol in the final material is equal to 30 wt%. The formation of metallic silver was confirmed by an appearance of a surface plasmon resonance band at 420-430 nm in UV spectra and the appearance of two diffraction peaks at 38.17° and 44.15° in X-ray diffraction pattern as well, corresponding to the crystallographic planes (111) and (200) of a face centered cubic lattice of Ag0. Dielectric spectroscopy data show that the increasing of glycerol content up to 30-40 wt.% leads to enhance the conductivity by three orders in comparison with the initial PVA. An increase in the silver content resulted in further rise of the conductivity, reaching value of 5.72 10-6 S/cm at 15 wt.% of silver concentration, at room temperature (20 °C). At 100-120 °C, the conductivity was the highest for the composite with 25 wt.% of AgNO3 - 3.67-3.84 10-4 S/cm. The resulting samples had high physical and mechanical properties: relative elongation of about 400%, tensile strength of 32-36 MPa. Studies of the dynamic light scattering of films solution with Ag NPs showed that the smallest size was for the sample with 0.5 wt.% - 6.3 nm. [ABSTRACT FROM AUTHOR]

The paper considers the advantages and disadvantages of existing methods for temperature compensation of data from fiber-optic sensors based on fiber Bragg gratings as part of an embedded system for simultaneous testing of deformation and temperature of polymer composite materials. It is shown that when external temperature testing is impossible, it is most expedient to implement the method of two optical fibers with different sensitivity to at least one of these parameters due to different dopants. Technological issues related to the formation of a spatial topology and the provision of an effective survey of the embedded optical system for monitoring polymer composite materials by the two-fiber method are considered. The results of theoretical research of a linear model of temperature compensation, a model that takes into account the influence of cross sensitivity, as well as a quadratic model of temperature compensation of optical testing data are presented. It has been established that the linear model is the simplest, however, when using it, one should take into account the error associated with the inaccuracy of the approximation of optical inspection data by a linear function. At the same time, it is shown that in order to improve the quality and reliability of the results of optical testing, it is advisable to use a quadratic model of temperature compensation, which provides an error level comparable to the error of the fiber-optic sensor survey device. The results obtained can be used to develop methods for the simultaneous testing of samples, as well as monolithic and three-layer structures from structural layered polymer composite materials with limiting molding conditions (temperature less than 180°C, specific pressure lower than 0.7 MPa), as in the process of bench and other tests, and, in the future, in real operating conditions. [ABSTRACT FROM AUTHOR]

Cryomilling is a promising method for fabricating polymeric blend and composite powder raw materials for various subsequent manufacturing processes. In this study, biodegradable porous membranes were fabricated from poly (ε-caprolactone) (PCL) using the cryomilling/hot pressing/porogen leaching approach. Powder mixtures of six different model compositions were compounded by cryomilling; thereafter, films were fabricated by hot-pressing. Poly (ethylene-oxide) (PEO) and salt were utilized as eco-friendly porogens in these mixtures, which were dissolved in water to introduce porosity in the films. Wood sawdust (WSD) and alum were investigated as fillers potentially capable of manipulating the hydrophilicity, mechanical and antimicrobial properties of the membranes. The morphological, hydrophilicity, mechanical, and filtration efficiency properties were explored and compared to those of commercial laboratory microfiltration (MF) membranes. SEM analysis revealed dense membrane skins for all compositions, along with lamellar porous structures. Mean pore radius ranged from 0.15 to 0.21 μm, which is within the MF pore size range. Water contact angle measurements averaged 70° and decreased with the addition of WSD and alum, indicating increased hydrophilicity. Tensile test results showed a decrease in mechanical properties, with higher porosities and with the addition of WSD. Adding alum (≥10 wt%) resulted in embrittled membranes. Filtration performance was evaluated in terms of pure water flux and turbidity reduction for textile wastewater, and it compared favorably to commercial membranes. In conclusion, this study has successfully introduced a new facile and versatile membrane fabrication approach. [ABSTRACT FROM AUTHOR]

Metamaterials are architected cellular materials, also known as lattice materials, that are inspired by nature or human engineering intuition, and provide multifunctional attributes that cannot be achieved by conventional polymeric materials and composites. There has been an increasing interest in the design, fabrication, and testing of polymeric metamaterials due to the recent advances in digital design methods, additive manufacturing techniques, and machine learning algorithms. To this end, the present review assembles a collection of recent research on the design, fabrication and testing of polymeric metamaterials, and it can act as a reference for future engineering applications as it categorizes the mechanical properties of existing polymeric metamaterials from literature. The research within this study reveals there is a need to develop more expedient and straightforward methods for designing metamaterials, similar to the implicitly created TPMS lattices. Additionally, more research on polymeric metamaterials under more complex loading scenarios is required to better understand their behavior. Using the right machine learning algorithms in the additive manufacturing process of metamaterials can alleviate many of the current difficulties, enabling more precise and effective production with product quality. [ABSTRACT FROM AUTHOR]

High temperature vulcanized silicon rubber (HTV-SiR) insulating materials are employed around the globe for the outdoor insulation of high voltage transmission lines. The biodegradable nature of these materials is the main hurdle to their reliable operation under severe outdoor conditions. For this reason fillers with different sizes, concentrations, shapes and dimensions are added to the base polymers to improve their performance. In this work, one pristine and three HTV-SiR composites were prepared having micro/nano fillers of silica and ATH. The samples were placed in a specially fabricated weathering chamber for a time period of 5000 h having different stresses along with bipolar DC voltage. The performance of prepared composite materials was analyzed using electrical, mechanical, thermal, surface and chemical analysis techniques. After aging, the highest value of leakage current recorded for sample S1 was 8.12 µA under positive DC voltage and the lowest value recorded was 5.82 µA for sample S4 under negative DC voltage. S1 became hydrophilic having HC4 and HC5 classes and S4 retained its hydrophobicity having HC3 and HC2 classes under bipolar DC voltage at the end of aging duration. TGA results showed residual % yield for S1, S2, S3 and S4 was 35.4%, 40.99%, 42.84% and 45.9% respectively under positive DC voltage. Moreover, fourier transform infrared spectroscopic analysis revealed that hybrid composite S4 showed the highest intactness in siloxane backbone (Si–O–Si) bonds with a decrease in its peak of 32.3% for positive DC and 17.2% for negative DC. Scanning electron microscopy showed voids, cracks, increased roughness and chemical structure damages on samples S1 and S2, whereas, co-filled composites S3 and S4 had better surface morphology. [ABSTRACT FROM AUTHOR]

The research was focused on developing new materials using natural products, which is the valuable or suitable way to solve environmental related issues and increase the income of farmers and industries. The work was carried out using corn fibres polyester composites. The composites were produced by adding fibres at different weight fractions as FRP10, FRP20, FRP30, FRP40 and FRP50 percentages. The optimum fibre mass fraction required for flexural strength using corn fibre is 18.05(MPA) and the impact energies and Hardness of the composites were lower than that of the control which were 1.41(J/mm²) and 2.01(BHN) respectively. In the results from the analysis of the mechanical properties of corn fibers reinforced composites greatly influenced by the fiber percentages with the observed strength from flexural and hardness. The impact of the polyester samples was improve the flexure responses of the developed composite materials. Likewise the work justifies the economic consumption of these otherwise waste materials that are detrimental as environmental pollution agent. [ABSTRACT FROM AUTHOR]

This study investigates the impact of a binary filler on the physicomechanical and tribological properties, as well as structure, of polymeric composite materials based on ultra-high-molecular-weight polyethylene. The organic modifier—2-mercaptobenzothiazole and wollastonite particles synthesized from two different systems (modeled and derived from waste) were used as the binary filler. The synthesis of wollastonite was carried out in the complex model system (CaSO4·2H2O–SiO2·nH2O–KOH–H2O) and from technogenic waste (borogypsum). It was demonstrated that the introduction of the binary filler made it possible to obtain an optimal combination of mechanical and tribological properties. It was found that during the wear of polymeric composite materials loaded with organic fillers, the fillers migrate to the friction surface, providing a shield against abrasive wear of the steel counterface. Due to the modification of ultra-high-molecular-weight polyethylene by 2-mercaptobenzothiazole, the interdiffusion of polymeric matrix macromolecules and interphase coupling with wollastonite particles improve. The 2-mercaptobenzothiazole organic compound used as the filler facilitates the relaxation processes within the composite under external loads. [ABSTRACT FROM AUTHOR]

Polymeric composite materials attracted attention when pristine polymers alone could not fulfill the necessity of high-performance functional materials for wide applications. Mixing two or more polymers (blends) together or compositing the polymers with inorganic compounds/carbon-based nanomaterials greatly solved the problem associated with the mechanical, thermal, and electronic properties along with the chemical stability, which paves a new pathway for optimizing the functional properties of active materials. However, a mere mixing of individual components sometimes would not provide enhanced properties due to the formation of phase-separated, larger domains of components. In particular, the grain boundaries of components, also known as "interfaces", actually determine the properties of these composite materials. The tuning of interfacial properties is significant to achieve composites with higher electrical conductivity and better charge transfer kinetics if they are targeted toward high-performance energy devices. This review aims to provide an overview of recent advancements in the area of polymeric composite materials with tuned interfacial characteristics towards energy conversion (solar cells, photocatalytic hydrogen production, and nanogenerators) and energy storage (supercapacitors and metal-ion batteries) devices with very recent representative examples. [ABSTRACT FROM AUTHOR]

Reinforced polymeric composites with natural fibers have garnered significant interest in recent years due to the need for biomass utilization and the requirements of various industries, such as automotive and construction. Among these natural fibers, Agave lechuguilla fiber, commonly known as ixtle (FIx) or Tampico fiber, exhibits important characteristics such as length, high strength, and durability. However, there is limited literature on its conditioning, functionalization, and utilization as a reinforcing material in polymeric composites (CP). This study presents the optimization of the alkali-silane treatment of FIx, identifying the most suitable reaction conditions to enhance their thermal stability, tensile strength, and silane coupling agent (ACSi) grafting on the fiber surface. The chemical treatment with ACSi proved highly effective, resulting in a significant grafting content, which was confirmed through FTIR and SEM–EDS analyses. The high level of functionalization did not compromise the mechanical performance of the fibers, suggesting that functionalized FIx holds great potential as a reinforcing material in CP. These findings open new paths for the sustainable use of Agave lechuguilla fibers, contributing to the development of environmentally friendly and high-performance polymeric composites in various industrial applications. [ABSTRACT FROM AUTHOR]

Herein, ethylene-vinyl acetate copolymer/styrene ethylene butylene styrene (EVA/SEBS) blend foam with wide effective damping temperature range (ΔT) was prepared via supercritical nitrogen. The influence of the ratio of EVA and SEBS on the foaming and damping properties was studied. ΔT gradually widened into the high temperature region with the increase of SEBS content, and higher SEBS gave denser and more uniform cell structure and reduced the density of the blend foam. When the content of SEBS was 40 phr, the density of the blended foam was 0.185 g/cm³, and the ΔT was -3~54°C. These damping foams were lightweight and this work showed that damping performance could be controlled by simply adjusting blend content, which is of great significance to broaden the application environment of damping materials. [ABSTRACT FROM AUTHOR]

Three-dimensional (3-D) printing technology (3-DPT) also referred to as additive manufacturing (AM) has advanced rapidly and is vastly used in varying manufacturing fields because of the minimization of waste materials and the ability to form complex geometrical shapes from micro- to macroscale. Nowadays, additive manufacturing (AM) has emerged extensively in varying engineering, architectural, medical, industrial, and manufacturing fields. Four-dimensional (4-D) printing technology (4-DPT) synergizes 3-DPT with stimuli-sensitive materials and has garnered wide attention for smart additive fabrication. More so, 4-DPT has displayed great prospects in numerous engineering applications including origami actuators, drug transport, robotics, smart clothing, and adaptive metamaterials. Hence, this elucidation presents recent advances in PLA additive manufacturing (3-DPT) and applications. Insight into 4-DPT is also presented. [ABSTRACT FROM AUTHOR]

Several high-explosive (HE) crystals are known to be piezoelectric. However, no systematic study has been carried out on how this effect can be utilized. In this paper, we report the results of an analysis on the response of composites consisting of HE crystals and a polymeric binder under electrostatic excitation. The HE crystals considered are 1,3,5-trinitroperhydro-1,3,5-triazine, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, pentaerythritol tetranitrate, and ammonium perchlorate. To explore avenues for enhancing the piezoelectric effect, the binder of the composites is taken to be piezoelectric polyvinylidene fluoride. The focus is on the distributions of induced electric field vector and mechanical stress in the microstructures. The effects of crystal–binder volume fraction, HE crystal size, and dielectric constants of the HE crystals are investigated. To further explore the effect, microparticles of lead zirconate titanate piezoelectric ceramic are introduced to some microstructures. For the HE crystals considered here, a coupled electromechanical analysis shows that the microstructural heterogeneities can enhance the local electric fields to as high as 1.34 times the applied E-field, causing the dielectric breakdown field strength of the overall composite to be much lower than the breakdown strengths of the constituents in the microstructure. In addition, the induced stress levels just prior to dielectric breakdown are well below the yield strengths of the respective constituents. As such, controlled dielectric breakdown, rather than mechanical damage, should primarily be used to facilitate hotspot formation, ignition, and chemical reaction. The likelihood of local dielectric breakdown within the HE crystals is systematically quantified as a function of applied electric field, microstructural attributes, and constituent behavior. To gauge the effect of the direct piezoelectric effect, one material case is also subjected to mechanical excitation in the form of compression. Under an applied external stress, the results show that the direct piezoelectric effect can lead to local yielding and thereby serve as a hotspot generation mechanism. On the other hand, the induced E-field is weak and unlikely to serve as a practical or efficient means of effecting hotspots within an energetic material. The analysis points out that simultaneous application of electrostatic excitation and mechanical excitation can also be considered. [ABSTRACT FROM AUTHOR]

The article discusses the use of biowastes as reinforcements for sustainable polymer composites, highlighting the economic, environmental, and social benefits of utilizing biodegradable organic waste materials. Various biowastes such as cuttlebones, chicken eggshells, chicken feathers, and marine wastes are explored as potential fillers for creating environmentally friendly polymer composites. Researchers emphasize the importance of studying the potential uses of biowastes in materials and polymer composites to reduce costs and waste, with a focus on improving wettability, mechanical performance, and filler-matrix interfaces. The article suggests that further research in this field, including life cycle assessments of biowastes in composites, could pave the way for future sustainable developments. [Extracted from the article]

The Journal of Polymer Science highlights the 100th Anniversary Celebration of Sun Yat‐sen University (SYSU) and its significant contributions to polymer research. SYSU, founded in 1924, has become a top-tier university nationally and internationally, with a renowned department of polymer science established in 1955. The university's polymer research covers various areas such as controlled polymerization, polyolefins, biomedical polymers, polymeric composites, and flexible electronic devices, showcasing innovative advancements in the field. The special issue of SYSU shares recent research activities, providing valuable insights into the future of polymer science and engineering. [Extracted from the article]

AbstractThe increasing concern for ecological preservation has prompted the development of new and innovative green materials that produce minimal environmental pollution. In this context, natural polymers have gained significant attention in recent times. Sugarcane Bagasse fibre, in particular, has undergone several chemical modifications, which have greatly enhanced its potential for various fields of interest. The advantages of sugarcane bagasse fibres are numerous and noteworthy. These fibres are a valuable by-product with qualities such as abundance, biodegradability, flexibility during processing, minimal health hazards, relatively high tensile and flexural modulus, low density, affordability, and recyclability. The chemical modification is done either by introducing a certain functional group on its surface or by modifying the chemistry of bagasse. These chemical structural changes reported to improve the matrix adherence and improving the composites mechanical properties. This review provides information on the application of surface-modified sugarcane bagasse and their materials from packaging to fillers. Also, this review article aims to give a detailed overview of the research on the use of sugarcane bagasse in reinforced composites, as well as its advancements and applications.

This article reviews the present status and prospects of sustainable bamboo fiber reinforced polymeric composites (BFRCs). Because of its rapid growth, renewability, and minimal environmental effect, bamboo has emerged as a viable contender in response to the increasing demand for eco-friendly materials across a variety of sectors. Bamboo is going to be a significant lignocellulosic material. Moreover, a summary of the production procedures, mechanical qualities, and uses of bamboo fiber reinforced composites also discussed. The problems and possibilities connected with the development of BFRCs which negatively influence their performance in a variety of industrial applications also addressed further.

Several solutions have been presented to minimize the environmental impact generated by polymers produced from petroleum resources. This work produced a biopolymer using glycerol, starch (<5) and macaúba epicarp fiber (10–15–20–25–30%) as reinforcement. The interaction of glycerol with starch was favored by the addition of acetic acid (CH3COOH). The pH was adjusted with sodium hydroxide (NaOH) at a concentration of 0.1 mol·L−1. The characterization was carried out through scanning electron microscopy (SEM), infrared reflectance—FTIR, water solubility, biodegradability and technological properties. Through the results obtained in this work, it is observed that the tensile strength and modulus of elasticity are influenced by the addition of the fiber concentration; the sample that received a 30% addition presented 19.17 MPa and 348.12 MPa, respectively. All samples showed low solubility in water and low density, in addition to a high rate of degradability in soil with mass loss corresponding to 59% over a period of three months. The results of this investigation are satisfactory for the production of materials that can be used in everyday life, replacing conventional plastic. [ABSTRACT FROM AUTHOR]

Carbon neutrality has led to a surge in the popularity of hydrogen tanks in recent years. However, designing high-performance tanks necessitates the precise determination of input material properties. Unfortunately, conventional characterization methods often underestimate these material properties. To address this limitation, the current research introduces alternative designs of ring tensile specimens, which enable accurate and reliable characterization of filament-wound structures. The advantages and disadvantages of these alternative designs are thoroughly discussed, considering both numerical simulations and experimental investigations. Moreover, the proposed ring tensile methods are applied to characterize thermoplastic composites for hydrogen storage tanks. The results indicate that the mechanical strengths and stiffness of carbon fiber-reinforced thermoplastic Elium® 591 composites closely match those of epoxy-based composites. This newfound accuracy in measurement is expected to contribute significantly to the development of recyclable hydrogen tanks. [ABSTRACT FROM AUTHOR]

Schematic overview for the preparation of polymer matrix EMI shielding composites based on external field-assisted techniques. [Display omitted] The rapid development of mobile devices has greatly improved the lives of people, but they have also caused problems with electromagnetic interference (EMI) and information security. Therefore, there is an urgent need to develop high performance EMI shielding materials to suppress electromagnetic radiation and prevent information leakage. Some reports point out that the self-orientation behavior of fillers under external forces contributes to the improvement of EMI shielding performance. So how to construct an effective filler orientation structure in the polymer matrix is becoming a hot topic in the research of EMI shielding materials. In view of the fact that there are few reports on the preparation of polymer matrix EMI shielding composites by external field induction, from this perspective, we first highly focus on strategies for the construction of conductive networks within composites based on external field induction. Subsequently, the research progress on the preparation of polymer matrix EMI shielding composites by inducing the orientation of inorganic fillers through external fields, including temperature, electrostatic, gravity, mechanical force and magnetic fields, is organized and sorted out in detail. Notably, the particular response relationship between the unique composite structures prepared by external field induction and the incident electromagnetic waves is further dissected. Finally, the key scientific problems that need to be solved in the preparation of polymer matrix EMI shielding composites assisted by external fields are proposed. The approach discussed and the strategies proposed are expected to provide some guidance for the innovative design of high-performance polymer matrix EMI shielding composites. [ABSTRACT FROM AUTHOR]

The dispersibility of fillers determines their effect on the mechanical properties and anisotropy of the 3D‐printed polymeric composites. Nanoscale fillers have the tendency to aggregate, resulting in the deterioration of part performance. An in situ filler addition method using the newly developed dual‐functional toughness agents (TAs) is proposed in this work for the homogeneous dispersion of carbon nanotubes (CNTs) in elastomer composites printed via multi jet fusion. The CNTs added in the TAs serve as an infrared absorbing colorant for selective powder fusion, as well as the strengthening and toughening fillers. The printability of the TA is theoretically deduced based on the measured physical properties, which are subsequently verified experimentally. The printing parameters and agent formulation are optimized to maximize the mechanical performance of the printed parts. The printed elastomer parts show significant improvement in strength and toughness for all printing orientations and alleviation of the mechanical anisotropy originating from the layer‐wise fabrication manner. This in situ filler addition method using tailorable TAs is applicable for fabricating parts with site‐specific mechanical properties and is promising in assisting the scalable manufacturing of 3D‐printed elastomers. [ABSTRACT FROM AUTHOR]

Technology has progressed a lot in the last 20 years, today it is possible to obtain new polymer composites that show performance properties. The ever-increasing demand for new high-performance materials has determined the appearance of new polymer structures based on elastomers and various wastes (protein, cellulosic, elastomeric, etc.) from various fields (shoes, leather goods, etc.). This paper describes the obtaining and characterization of polymer composites based on NBR rubber (butadiene-co-acrylonitrile) and protein waste from the footwear and leather goods industry, cryogenically ground to micrometric dimensions and modified with PDMS (polydimethyl siloxane). PDMS has the role of a plasticizer, but at the same time it improves the dispersion of protein waste mixed in the polymer matrix. The polymer composites were obtained by the mixing technique and tested from a physical-mechanical point of view according to the standards in force. The characterization in normal condition and accelerated aging at 70°C for 168 h (it was carried out hot, using the hot air circulation oven method) was carried out after the samples were subjected to conditioning for 24 h at ambient temperature. Also, the polymer composite samples were subjected for 365 days to atmospheric conditions (sun, rain, wind, hail, light, etc.) to see their influence on the properties of the obtained polymer composites. [ABSTRACT FROM AUTHOR]

In the present work, synthesized U-type barium hexagonal (Ba4Co1.5Zn0.5Fe36O60 or BaU) ferrite powder is further transformed into BaU/glass fiber-epoxy structural composites by hand lay-up process and compression moulding techniques using different volume percentages (11.4, 17, and 26.4) within reinforced polymer matrix. Phase formation, surface morphology, and magnetic properties by XRD, FESEM, and VSM techniques, respectively. Subsequently, the electromagnetic and absorbing properties of the designed structures were measured for typical incident EM waves in the frequency range of the C-band. The radar absorbing performance of the designed RAS composites was observed as −16.8 dB in the whole band, with maximum absorption (RL ≤ −10 dB) of adequate thickness at 2.2 mm. Additionally, the effects of the BaU particles on the mechanical properties of the designed polymeric composites were measured through ASTM standard data. The proposed RAS composites are the most demanding absorbers from a military and commercial point of view. [ABSTRACT FROM AUTHOR]