Enhanced performance of cellulose nanofibre reinforced styrene butadiene rubber nanocomposites modified with epoxidised natural rubber

The present work focuses on the potential use of Pandanus kaida proproot cellulose nanofibre as reinforcing filler for styrene butadiene rubber (S) vulcanizates in the presence of epoxidised natural rubber (E) as modifier. The incompatibility between the polar cellulose and non-polar styrene butadiene rubber can be overcome by the use of epoxidised natural rubber (E). This is a facile process compared to other strategies where cellulose nanofibers are chemically modified thus making the process expensive. Initially, cellulose nanofibre was extracted from Pandanus kaida prop root via hydrothermal assisted oxalic acid hydrolysis. FESEM image revealed that cellulose nanofibres (PN) had a diameter of around 15–30 nm. S/PN masterbatches were prepared via latex stage mixing, co-coagulated, later melt-mixed with E and other compounding ingredients followed by vulcanisation. The investigation of mechanical properties revealed that PN nanofiber at 5 phr loading (S/PN5) resulted in enhanced properties. For further improvement, epoxidised natural rubber (E) was used as modifier at various loadings in S/PN5. At 1 phr of E loading (S/PN5/E1), the tensile strength, modulus, tear strength and abrasion resistance index improved significantly by 150%, 47%, 93% and 19%, respectively, compared to S gum vulcanizates. Strain sweep studies indicated better fibre-matrix interaction in the presence of E1. DMA studies revealed a higher storage modulus, lower damping, higher cross-link density and lower adhesion factor for S/PN5/E1 composites.