Rice husk flour (RHF) biocomposites based on uncompatibilized and compatibilized recycled high density polyethylene/recycled polyethylene terephthalate (rHDPE/rPET) with ethylene‐glycidyl methacrylate (E‐GMA) copolymer were prepared through a two‐step extrusion and hot pressing with fiber loadings of 40, 60, and 80 wt %. Results showed that tensile and flexural properties increased. However, the elongation to break and impact strength decreased as the RHF loading increased. Compatibilizing polymer blend matrices can further enhance the mechanical properties. Water absorption (WA) test were examined in distilled and seawater. It is interesting to note that for composites made from uncompatibilized matrix, the calculated D and KSR were lower in seawater, but for the compatibilized matrix composites, the D and KSR obtained were generally lower in distilled water. However, compatibilization of rHDPE/rPET has been markedly reduced the WA and thickness swelling. Scanning electron microscope analysis of the compatibilized matrix composites confirmed the improved interfacial bonding of matrix–matrix and filler–matrix phases. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41494.

Biocomposites of recycled high-density polyethylene (rHDPE)/recycled polyethylene terephthalate (rPET) matrices with a high loading of rice husk flour (RHF) were fabricated through a two-step extrusion. The use of ethylene-glycidyl methacrylate (E-GMA) copolymer improved the compatibility of the immiscible rHDPE/rPET blend. Maleic anhydride polyethylene (MAPE) was used as a coupling agent to increase the adhesion of the fibre–matrix interface. In this study, the effect of natural fibre loadings on rHDPE/rPET blends was examined. The water absorption process in the RHF-filled composites followed the kinetics and mechanisms of Fickian diffusion. Compared with samples without RHF, the rHDPE/rPET/RHF system had 58–172% higher tensile modulus and 80–305% flexural modulus. The thermal stability of the composites slightly increased with the addition of the RHF filler. The storage modulus of biocomposites was greatly enhanced by RHF. From these results, we can conclude that RHF can work well with rHDPE/rPET for manufacturing high loading biocomposite products.

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This study investigated the sonication effect on the mechanical properties of thermoplastic natural rubber (TPNR) nanocomposites reinforced by multi-walled carbon nanotubes (MWCNTs). The TPNR nanocomposites were prepared using the melt blending method from polypropylene, natural rubber and liquid natural rubber as a compatibilizer, respectively, with 1% of MWCNTs. The results showed that a good dispersion on nanotubes was achieved by sonication. An optimal sonication time of 1 h was found to produce nanocomposites with maximum tensile and impact strength. The Young’s modulus, tensile strength, elongation at break and impact strength increased by almost 11%, 21%, 43% and 50%, respectively as compared with a pristine TPNR sample. The effect of sonication was also confirmed by dynamic mechanical analysis, it showed that the storage modulus E′, loss modulus E″ and glass transition temperature ( Tg) also increased for all MWCNTs reinforced samples. Scanning electron micrographs confirm the effect of good dispersion of MWCNTs and their interfacial bonding in TPNR after sonication.

Conventional polymer blending has a shortcoming in conductivity characteristic. This research addresses the preparation of conductive thermoplastic natural rubber (TPNR) blends with graphene nanoplates (GNPs)/polyaniline (PANI) through melt blending using an internal mixer. The effect of PANI content (10, 20, 30, and 40 wt %) on the mechanical and thermal properties, thermal and electrical conductivities, and morphology observation of the TPNR/GNPs/PANI nanocomposites was investigated. The results showed that the tensile and impact properties as well as thermal conductivity of nanocomposite had improved with the incorporation of 3 wt % of GNPs and 20 wt % of PANI as compared to neat TPNR and reduced with further increase of the PANI content. It was observed that the GNPs and PANI acted as a critical component to improve the thermal stability and electrical conductivity of the TPNR/GNPs/PANI nanocomposites. The most improved conductivity of 5.22 E‐5 S/cm was observed at 3 wt % GNPs and 40 wt % PANI. Variable‐pressure scanning electron microscopy micrograph revealed the good interaction and distribution of GNPs and PANI within TPNR matrix at PANI loadings lower than 30 wt %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48873.

The thermal conductivity and mechanical performance of a hybrid multi‐walled carbon nanotubes/silicon carbide (MWCNTs/SiC)‐reinforced thermoplastic natural rubber (TPNR) nanocomposite were investigated. TPNR was fabricated from polypropylene, natural rubber (NR) and liquid NR at a volume ratio of 70:20:10, respectively. The Young's modulus, the tensile strength, and the storage and loss modulus of the nanocomposites with a single filler of MWCNTs or SiC were enhanced compared with those of neat TPNR. The greatest improvements in these properties were achieved at a composition of 1.5 wt% SiC‐1.5 wt% MWCNTs‐reinforced nanocomposite. In addition, the thermal conductivity and specific heat capacity of the nanocomposites, determined using a laser flash technique, were improved in the 3 wt% SiC‐reinforced nanocomposite sample relative to those of the pure sample and the other reinforced nanocomposites. Based on these findings, MWCNTs and SiC could serve as suitable percolated networks of hybrid reinforcement fillers to achieve optimal thermal and mechanical properties in the TPNR matrix. POLYM. COMPOS., 40:E695–E703, 2019. © 2018 Society of Plastics Engineers

This study investigated the mechanical properties of thermoplastic natural rubber (TPNR) nanocomposites reinforced by multi-walled carbon nanotubes (MWNTs). The TPNR nanocomposites were prepared using melt blending method from polypropylene, natural rubber, and liquid natural rubber as a compatibilizer, respectively, with 1—7 wt% of MWNTs. The tensile strength and Young’s modulus increased by almost 39% and 30%, respectively, at 3 wt% of MWNTs. The elongation at break decreased with increase in the percentage of MWNTs. The maximum impact strength was recorded at 5 wt% of MWNTs which was increased by 74% as compared with a pristine TPNR sample. The effect of MWNTs was also confirmed by DMA; it showed that the storage modulus E′, loss modulus E′′, and glass transition temperature (Tg) also increased for all MWNT reinforced samples. SEM micrographs confirm the effect of good dispersion of MWNTs and their interfacial bonding in TPNR.

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