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The need for eco‐friendly materials has been attracted due to renewability, abundance availability, low cost, and so on. Therefore, the search for bio fillers for the fabrication of bio‐based composite materials is gaining more and more attention in both academic and industry circles because it promotes sustainability. The present study represents the utilization of biomass solid waste in the hybrid form of Tamarind Seed and Date Seed Filler (TSF/DSF) into polymer reinforced composite which has been explored for the first time by a compression molding technique. These fillers are bio‐waste that can be obtained at a minimal cost from renewable sources. An attempt has been made to use these hybrid fillers to reinforce the matrix ranging from 0 to 50 wt%, and their physical, mechanical, and thermal properties were investigated. In general, the inclusion of hybrid fillers increases mechanical properties, although the addition of hybrid fillers had only a minor impact on thermal properties. When compared to the pure vinyl ester resin, the hybrid fillers reinforced composites revealed a significant enhancement in tensile, flexural, impact, and hardness properties, with improvements of 1.51 times, 1.44 times, 1.87 times, and 1.46 times respectively, at 10 wt% filler loading. Filler matrix interaction of fractured mechanical testing samples was evaluated by scanning electron microscope. Based on the findings, hybrid filler reinforced composites may be suitable for applications where cost is a consideration and where minor compromises in thermal qualities are acceptable. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (RGO) is an effective polymer filler for shielding against electromagnetic interference (EMI). Its shielding efficiency rises as its concentration in polymer matrices increases. However, higher filler loading impedes polymer foaming and deteriorates the mechanical properties of the resulting foam. The goal of this work is to determine the optimal RGO concentration that can be loaded into polyurethane (PU) matrix to produce a composite foam with a high level of electromagnetic shielding along with good mechanical properties. To that end, different PU foam samples containing varying amounts of RGO were synthesized. The synthesized samples were characterized by scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infra‐red (FT/IR) and universal testing machine. Furthermore, the shielding efficiency of the samples was measured using a vector network analyzer over the frequency range of 8–12 GHz. The results revealed that the increase in RGO concentration enhances the mechanical and thermal properties of the prepared composite foam materials. The shielding effectiveness reached −23 dB at 5 wt% RGO concentration. The polyurethane‐RGO composite foam materials have been identified as potentially viable materials for use in electromagnetic shielding applications. [ABSTRACT FROM AUTHOR]

Additive manufacturing technology can help us to produce complex components/parts easily. It can be used to develop the parts with multi‐material structures consisting of thermoplastic, thermosetting plastic, and ceramic fibers. This multi‐material structure enhances the performance of lightweight polymer‐based components. In this research work, poly‐lactic acid (PLA) lattice (mono‐material structure), PLA lattice filled with epoxy (bi‐material structure), and PLA lattice incorporated with embedded milled glass fibers (MGFs) in an epoxy matrix (tri‐material structure, TMS) were designed and developed by fused filament fabrication and solution casting methods. PLA lattice of 50% volume was fixed in all structures and 50% volume was filled with epoxy and MGFs. The dispersed MGFs in epoxy matrix were varied from 0, 2.5, 5, and 7.5 vol%. The mechanical properties were carried out by compression test, three‐point bending test, and tensile test. The results revealed that 5 vol% of MGFs in the epoxy sample (TMS) exhibited improved mechanical performances compared to other samples. The cone‐beam CT scan results confirmed the voids/porous free surfaces in the developed materials. The high‐resolution scanning electron microscope microstructural evolutions in‐terms of topography and fractured regions were also examined and reported. [ABSTRACT FROM AUTHOR]

A hybrid composite material was obtained by stacking carbon fiber reinforced plastic (CFRP) onto 7075‐W Al alloy sheet. Mechanical properties of the CFRP/Al hybrid composite material were measured by tensile and flexural tests. To investigate the flow of the epoxy, the thinning was measured using an optical microscope and the defects were observed by a scanning electron microscope. A finite element model was established to predict the thickness and the contact pressure distributions of the CFRP/Al hybrid composite material during the forming process. The results showed that the tensile strength (TS) of the CFRP/Al hybrid composite was increased by 10% and the fracture strain was increased by 24% compared with the single 7075 Al alloy. The flexural strength (FS) and the displacement of the loading nose were improved by 13% and 75%, respectively. According to the microstructure observation, large cracks in the epoxy could be found on the side wall of the U shape part. The results of numerical analysis indicated that the low contact pressure at side wall was the main reason for the decrease of the tensile and FS and the delamination between laminates. [ABSTRACT FROM AUTHOR]

Silicon carbon black (SiCB), a kind of biomass carbon material, is a kind of pyrolysis ash prepared by anoxic pyrolysis of rice husk. When filled as an inorganic reinforcement in the composite material basalt fiber (BF) reinforced polyamide 6 (PA6), it has synergetic effect with the POE‐g‐MAH elastomer. Differential scanning calorimetry analysis shows that KSiCB plays a role of heterogeneous nucleation in the composite material, accelerates the nucleation and crystallization speed of PA6, and can increase the strength and rigidity of the composite material. Scanning electron microscope observation of the fracture surface of the composite material shows that the addition of KSiCB can effectively "pin" and inhibit crack propagation. When the content of KSiCB is 2.5 phr, the tensile strength of the composite material KSiCB/POE‐g‐MAH/PA6(BF) reaches a maximum of 125.194 MPa, the tensile modulus is 2791.257 MPa, the bending strength reaches 192.034 MPa, and the impact toughness reaches 23.42 kJ/m2. [ABSTRACT FROM AUTHOR]

ZnS‐reinforced ZnS/ZnSe composites are prepared by chemical vapor deposition. Scanning electron microscope, transmittance, and bending strength are used to characterize the samples. The schematic diagram of the transmittance model of the double‐layer composite window is used to calculate the theoretical transmittance, and the measured value of the transmittance of ZnS/ZnSe composite material is in good agreement with the calculated value. The effects of interface layer on the optical and mechanical properties of materials are studied in detail. It is found that the interface can affect the transmittance of the composites, but it still maintains a high transmittance, and the influence of interface layer on the transmittance of visible band is more serious than that of infrared band. Moreover, the mechanical properties of the new composite material are significantly improved (35%). [ABSTRACT FROM AUTHOR]

To improve fire retardant behavior of bio‐epoxy resin, composites were prepared with three fire retardants (FRs); ammonium polyphosphate, aluminum trihydrate, and magnesium hydroxide. Fractured surfaces of prepared composites were observed with the scanning electron microscope (SEM). Tensile strength and Charpy toughness were evaluated and analyzed statistically using analysis of variance (ANOVA). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to determine the thermal stability. SEM analysis results revealed fractured surfaces were altered with addition of FRs. Adding FRs can be regarded as a decrease in tensile strength and toughness complemented by improved stiffness. ANOVA analysis showed FR/bio‐resin composites have a statistically significant loss in tensile strength, stiffness, elongation, and Charpy toughness. The DSC results showed the glass transition temperature was not affected significantly by adding FRs and ranged from 66 to 69 °C. TGA showed the initial, midway, and maximum decomposition temperatures for composites and their ability to form improved ash yields compared to pure resin. Aluminum trihydrate and Mg(OH)2 had higher T50 suggesting an increase in thermal stability compared to pure bio‐epoxy. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47398. [ABSTRACT FROM AUTHOR]