Summary Properties of the unfilled rubber blends (Natural rubber, NR and Nitrile Butadiene Rubber, NBR) were poor due to the absence of reinforcing agent. However, the strength of compound had been improved with the addition of nanofiller. There were two (2) types of nanofillers that had been introduced which are nanoclay (NC) and nanosilica (NS). NR/NBR composites were prepared by open milling process where different amount of nanofiller was added ranging from 1 until 7 phr. There are a few possibilities might occur when using small particles size of fillers especially in term of interaction between rubber‐filler and filler‐filler interaction. Apart from that, different polarity and composition of both rubbers were influenced the interaction between filler and rubber phases. The interaction between non‐polar and polar rubber was enhanced using epoxidized natural rubber (ENR). The rubber compound was cured via a conventional sulphur vulcanization system. The cure characteristic result shows that the incorporation of nanofiller does not affect much on the t90. The physical and mechanical properties of epoxidized natural rubber (ENR) compatibilized NSi‐NR/NBR blends were determined by conducting the density measurements, hardness and tensile tests. The NC filler gave the highest tensile strength compared to NS. On top of that, reduction trend on the tensile strength observed at 3 phr of NS loading due to the formation of NS aggregates. The values of moduli, hardness and densities of vulcanizates increased as the nanofiller loading increased. It occurs due to better filler dispersion in the rubber matrix and strong interaction between filler‐rubber phases. The result shows that NC has more pronounce effect on the physical and mechanical proportion of the rubber vulcanizates.

Rising environmental issues and huge disposal of rubber waste have resulted in an increased interest in the usage of reclaimed rubber (RR) to produce sustainable and environmental friendly applications. In this study, incorporation of butyl reclaimed rubber into carboxylated nitrile butadiene rubber (XNBR/BRR) was carried out where the loadings of each XNBR and BRR were varied. The rubber was cured with sulphur during the melt mixing using a two-roll mill. This study is aimed to investigate the applied BRR loading towards the physical and mechanical properties of the XNBRcompounds. The results appeared that the optimum cure time (T90) increased and curing rate index (CRI) showed that a faster curing reaction with the increase in the content of BRR where the T90 had an increment of 89% while the CRI was faster by 89%. As for the crosslink density which indicates the density of chains or segments in polymer network, it decreased about 20% with increasing level of BRR. Also, the compression set which refers to the ability of rubber to resist permanent deformation, had an increase of 73% as the loading ratio of BRR increased. These results were obtained due to the low molecular weight of the BRR where the high shear and temperature during the reclamation process severely breaks down the molecular chains of the BRR into shorter segments. With the results obtained, it is shown that reclaimed rubber has the potential for further development and could increase the interest of researchers all around the world in the incorporation of reclaimed rubber for footwear application.

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Starch has potential to be used in new, functional food packaging materials. The attractive factors of starch as a packaging material are its low price and degradable properties. However, brittleness hinders its function as a packaging film. In this study, chitosan nanofillers (CSN) were incorporated into sago starch (SS) formulations to improve the mechanical, physical, and chemical properties of the film. The synthesis of a new formulation from the optimization process resulted in increased mechanical properties; the tensile strength obtained for the sago starch/chitosan nanofillers (SS/CSN) film was 88 MPa compared with 46 MPa for the sago starch film (SSF). In terms of thermogravimetric analysis, the SS/CSN film sustained up to 390 °C with 60% weight loss, whereas SSF experienced a weight loss of 67% at 375 °C. The analyses summarize the concept of using biocomposites to improve the properties of film for the potential purpose in biodegradable packaging plastics.

With the rapid development of the palm oil-related industry, this has resulted in the high production of palm oil waste. The increasing amount of palm oil waste has become an alarming issue in which researchers have carried out studies that this palm oil waste has the potential to be used as a biomass source. Carbon black (CB) is the most preferred reinforcing filler in the rubber industry but it has a disadvantage where CB is carcinogenic and a petroleum-based product. Hence CB is less sustainable. Palm kernel shell (PKS) derived from palm oil waste can be turned into palm kernel shell biochar (PKSBc) which can potentially be a value-added, sustainable biofiller as reinforcement in rubber composites. In this study, PKSBc is hybridized with CB (N660) at different loading ratios to be filled in carboxylated nitrile butadiene rubber (XNBR). This study aims to elucidate the effect of the varying ratios of hybrid CB/PKSBc on the rheological properties, abrasion resistance, and hardness of XNBR composites. In this study, both CB and PKSBc are incorporated into XNBR and were then cured with sulphur. The composites were prepared by using a two-roll mill. Different compositions of hybrid CB/PKSBc were incorporated. The rheological properties and physicomechanical properties, such as abrasion resistance and hardness of the vulcanizates, were investigated. Based on the results, as the loading ratio of PKSBc in hybrid CB/PKSBc increases, the cure time decreases, and the cure rate index increases. The abrasion resistance and hardness values of vulcanizates were maintained by the high loading of PKSBc which was due to the porous structure of PKSBc as shown in the morphological analysis of PKSBc. The pores of PKSBc provided mechanical interlocking to reduce volume loss and maintain the hardness of vulcanizates when subjected to force. With this, PKSBc is proven to be a semi-reinforcing filler that could not only act as a co-filler to existing commercialized CB, but PKSBc could also fully substitute CB as reinforcement in rubber, specifically XNBR as it is able to provide high abrasion resistance and hardness to the rubber composites. This would mean the performance of PKSBc is comparable with CB (N660) when it comes to maintaining the physicomechanical properties of XNBR composites in terms of abrasion resistance and hardness. Therefore, this approach of using eco-friendly filler derived from palm oil agricultural waste (PKSBc) can reduce the abundance of palm oil waste, be a sustainable alternative to act as a co-filler in hybrid CB/PKSBc to decrease the usage of CB, and helps to enhance the quality of existing rubber-based products.