ORALS

 Green composites are an alternative to conventional non biodegradable composites in many applications. In the reported work, the mechanical and physical properties of vulcanised natural rubber (NR) reinforced with wool fibre were investigated. A comparative study of vulcanised rubber with vulcanised rubber-wool composite was conducted with emphasis on diffusion characteristics, moisture absorption, thermal and UV degradation, biodegradation, acoustic properties, cure characteristics etc. The developed NR-wool composite contained 50% vulcanised rubber and 50% wool fibre. Various analytical techniques such as XRD, SEM, FTIR, etc. were adopted to characterize both vulcanised rubber and the composites. The thermal and UV degradation of the composites were also investigated by keeping the composites for ageing under standard conditions. The results showed that, in comparison with the vulcanized rubber sample, the tensile strength of the NR-wool composites was reduced whereas, the hardness increased by 84.26%. During diffusion studies, it is observed that the mol % uptake of toluene into the matrix of the composites was considerably less in comparison to that of vulcanised rubber. The cure time data shows that the maximum torque in the cure curve which is an indication of the extent of crosslinking increased to almost 500% in the NR-wool composites in comparison with vulcanized rubber. After incorporating 50% wool in NR, the curing time was reduced to almost half in comparison with vulcanized rubber. The cross-sectional SEM images depict fibre pullout and voids, which indicates less interfacial adhesion of the wool fibre with the rubber matrix. The FTIR studies indicate no specific chemical interaction between the wool and NR inside the composites. The moisture uptake of the NR-wool composite was found to be higher than the vulcanized rubber due to the presence of hydrophilic wool fibre.