Interfacial interactions and properties of natural rubber-silica composites with liquid natural rubber as a compatibilizer and prepared by a wet-compounding method

Natural rubber-silica [W(NR-SiO2)] composites were prepared by wet-compounding technology with liquid natural rubber (LNR) as a compatibilizer. The effects of the LNR content and wet-compounding technology on the filler dispersion, Payne effect, curing characteristics, mechanical properties, and interfacial interactions were investigated. The results show that the incorporation of LNR promoted vulcanization and decreased the Payne effect of the W(NR-SiO2) composites. With the addition of 5 phr LNR, the remarkable improvements in the mechanical properties of the W(NR-SiO2) vulcanizates were correlated with the improved silica dispersion and strengthened interfacial bonding. Furthermore, the W(NR-SiO2) vulcanizates containing LNR exhibited improvements in both the wet-skid resistance and rolling-resistance performance. The interfacial interactions, quantitatively evaluated by the Mooney-Rivlin equation and Lorenz-Park equation on the basis of the rubber elasticity and reinforcement theory, were strengthened in the presence of LNR. Accordingly, an interfacial structural model was proposed to illustrate the improvements in the mechanical properties of the W(NR-SiO2) composites. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46457.