a b s t r a c tA feasibility study was carried out on the utilization of Alkanolamide (ALK) on silica reinforcement of natural rubber (NR) by using a semi-efficient cure system. The ALK was incorporated into the NR compound at 1.0, 3.0, 5.0, 7.0 and 9.0 phr. An investigation was carried out to examine the effect of ALK on the cure characteristics and properties of NR compounds. It was found that ALK gave shorter scorch and cure times for silica-filled NR compounds. ALK also exhibited higher torque differences, tensile modulus, tensile strength, hardness and crosslink density of up to 5.0 phr of ALK loading, and then decreased with further increases of ALK loading. The resilience increased with increased ALK loading. Scanning electron microscopy (SEM) micrographs proved that 5.0 phr of ALK in the silica-filled NR compound exhibited the greatest matrix tearing line and surface roughness due to higher reinforcement level of the silica, as well as better dispersion and cure enhancement.

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This paper presents a comparison on the effects of blending chitin and/or starch with poly(lactic acid) (PLA). Three sets of composites (PLA–chitin, PLA–starch and PLA–chitin–starch) with 92%, 94%, 96% and 98% PLA by weight were prepared. The percentage weight (wt.%) amount of the chitin and starch incorporated ranges from 2% to 8%. The mechanical, dynamic mechanical, thermal and microstructural properties were analyzed. The results from the tensile strength, yield strength, Young’s modulus, and impact showed that the PLA–chitin–starch blend has the best mechanical properties compared to PLA–chitin and PLA–starch blends. The dynamic mechanical analysis result shows a better damping property for PLA–chitin than PLA–chitin–starch and PLA–starch. On the other hand, the thermal property analysis from thermogravimetry analysis (TGA) shows no significant improvement in a specific order, but the glass transition temperature of the composite increased compared to that of neat PLA. However, the degradation process was found to start with PLA–chitin for all composites, which suggests an improvement in PLA degradation. Significantly, the morphological analysis revealed a uniform mix with an obvious blend network in the three composites. Interestingly, the network was more significant in the PLA–chitin–starch blend, which may be responsible for its significantly enhanced mechanical properties compared with PLA–chitin and PLA–starch samples.

In the new era of sustainable developments, various adaptations have been carried out in many industries to revolutionize the quest for sustainable materials as a method to reduce the dependency on petroleum feedstock. One of such inventions focusing on the automotive industries with new concepts of energy automotive such as electric and hybrid cars, as well as the utilization of inorganic materials as a components of polymer composites, which is expected to reduce the demand and utilization of various rubber composites in automotive parts. However, due to remarkable increment of service life and inherent properties, ethylene propylene diene terpolymer (EPDM) has showed the highest consumption in automotive segments and the fastest development rate in the field of polymer modification. Thus, a comprehensive review concerning the development of environmentally friendly EPDM-based composites reinforced by various clay minerals is highlighted and presented in this article. The characteristic of EPDM, including the chemistry, processing, properties, and applications, as well as the current research on various types of rubber/clay composites, EPDM/clay composites, and rubber/bentonite (Bt) composites, is reviewed and reported. In addition, the characteristics, properties, and applications of different types of clay minerals such as layered silicates, Bt clays, and montmorillonites as reinforcement material in EPDM composites are also included. Finally, the drawbacks and challenges in developments of EPDM/clay composites and the existing improvizations through various compatibilization of EPDM/clay composite system such as chemical modification of clays, functionalization using coupling agents, and compatibilization through grafting are discussed by highlighting the important findings.

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