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This study compares the mechanical properties of recycled high-density polyethylene (r-HDPE)/rice husk (RH) composites from a twin-screw extruder and a heated two-roll mill, and the effect of different filler loadings using different melt blending processes on the mechanical properties of r-HDPE/RH composites. Polyethylene-graft-maleic anhydride (MAPE) acts as the coupling agent to enhance interfacial bonding between the fibre and the polymer matrix. The filler loading used was in the range of 10-40 wt. %. In this work, r-HDPE/RH blends were prepared using a twin-screw extruder and a heated two-roll mill. The ratio of 70/30 twin-screw extruder compounded composites significantly showed higher tensile based on improved to about 45.5% at 11 MPa compared to those compounded in the heated two-roll mill. The same ratio showed an increment almost up to 9% of elongation at break. It has also been verified that the higher filler loading used reduced the tensile strength and elongation at break, while the Young’s modulus increased. The result was evidenced by the increase in water absorption and longer burning time as the filler loading increased.

In this study, the effects of polyaniline (PANI) incorporation (3 wt% of PANI) and graphene nanoplatelets (GNPs) loading (0.1–0.7 wt%) on the mechanical, thermal, and electrical performance of epoxy matrix were investigated. The incorporation of 0.3 wt% GNPs optimally enhanced the bending strength, bending modulus, tensile strength, tensile modulus, and impact strength (90 MPa, 1422 MPa, 63 MPa, 602 MPa, and 8.29 kJm−2, respectively). At 0.3 wt% GNPs, the hybridization effect optimally enhanced the glass transition behaviour of the epoxy nanocomposites. The electrical and thermal conductivities of epoxy were improved upon the inclusion of PANI, and this increase was further augmented when the GNPs content increased to 0.3 wt%. However, higher GNPs contents deteriorated the mechanical performance and electrical and heat conduction. Field emission scanning electron microscopy showed good filler distribution and effective interactions among the GNPs, PANI, and epoxy components with appropriate compositions.

This study investigates the novel effect of poly(lactic acid) (PLA) optical purity on PLA/liquid natural rubber (LNR) blend films fabricated by solution casting. An investigation was conducted to examine how different levels of PLA optical purity affect the mechanical, structural, morphological, thermal, and barrier properties of PLA/LNR films. Infrared spectroscopy analysis revealed that the D‐isomer content of PLA significantly affected the chemical interactions between the LNR and PLA. The favorable chemical interaction between the LNR and PLA with a high D‐isomer content also increased the elongation at break by 300%. Morphological investigations proved that the chemical interaction also improved the dispersion and reduced the size of the LNR droplets formed in the PLA matrix. Notably, while low D‐isomer PLA blends showed decreased crystallinity (Xc) upon LNR addition, high D‐isomer PLA blends exhibited increased Xc by 460%, leading to a 42% increase in oxygen transmission rate. Additionally, hydrolytic degradation of high D‐isomer PLA increased by 259% with increasing LNR content. Overall, optical purity of PLA plays an important role in determining the properties of PLA blends. [ABSTRACT FROM AUTHOR]

Plastic wastes have caused serious environmental issues worldwide, and thus viable solutions for their replacement are now urgently needed. This work aimed to develop biocomposite materials based on polyethylene (PE) wastes as matrix reinforced with coconut fiber, without any additional chemical treatments, using extrusion and compression molding. The effects of polymer matrix type (high-density and low-density PE (HDPE and LDPE)) and fiber loading (5-15 wt%) on the mechanical properties and long-term water absorption behaviour of the materials were evaluated. Tensile strength results showed the optimum performance at 5 wt% fiber -- of 16.6 MPa for the HDPE matrix and 7.3 MPa for the LDPE matrix, but flexural and impact strengths reduced with the fiber loading. An increasing trend of water absorption capacity was noted as a function of filler loading and of the water temperature during immersion, with a weight gain of up to 5%, following the trend: cold water > room temperature tap water > hot water. From the results, HDPE based biocomposites had better mechanical performance and lower water absorption capacity, compared with LDPE based biocomposites. [ABSTRACT FROM AUTHOR]

We have demonstrated the significant impact of high density polyethylene (HDPE) crystallinity and structural morphology on the tensile strength of 60/40 NR/HDPE polymer blend composites. Introducing nanoscale Boron Carbide (B4C‐type compounds) fillers noticeably changed the crystallinity and morphology of HDPE, leading to the formation of fine spherulites. Conversely, microscale fillers mainly impacted the crystallinity while preserving a coarse architecture. Although both composites experienced a reduction in crystallinity, the nanocomposites outperformed microcomposites and even the pristine polymer blend in terms of strength, implying the effect of a fine structure. The nanocomposite with a filler loading of 2 wt% exhibited the highest strength. This investigation provides novel insights into the interplay between crystallinity, HDPE structure, and the size of fillers, which heavily influence the strength of polymer blend composites. [ABSTRACT FROM AUTHOR]