Application of bio-based vegetable oils as processing aids in industrial natural rubber composites

Rubber composites based on vegetable oils are being increasingly developed as these materials significantly reduce the use of petroleum-based carcinogenic oils as plasticisers in rubber products. Apart from renewability, vegetable oils have some functional groups such as polar group, double bond and long alkyl chain, which could make rubber performance more comprehensive, making processing oil from petroleum-based "one agent for one function" to bio-based "one agent for multiple functions". In this work, we selected one bio-based vegetable oil (FN-B17) as green processing aid for nature rubber (NR) composites and petroleum-based oils (PB-1,2,3,4,5) were also chosen to be investigated for comparison. The plasticisation effects of FN-B17 and other plasticisers on composites were systematically studied. In specific, Mooney viscosity, processing properties and cross-linking characteristics of composites with various kinds of oils were characterised while the mechanical properties and RPA dynamic behaviors were also evaluated. The results indicated that the performance of bio-based oil on processing and mechanical properties of NR composites are similar or even better than that of petroleum-based oils, whereas bio-based oil is renewable with lower cost, which would be cost-effective green processing oil that could replace petroleum-based oil for NR composites. Soon, the trend of utilising bio-based oil may bring considerable advancements in the performance of filled rubber composites in an environmentally acceptable and sustainable manner.