Significantly improved performance of rubber/silica composites by addition of sorbic acid

Sorbic acid (SA) was used to improve the performance of styrene-butadiene rubber (SBR)/silica composites by direct blending. The mechanisms for the significantly improved performance were studied by X-ray photoelectron spectroscopy, X-ray diffraction and by the determinations of bound rubber content and crosslink density. The strong interfacial bonding between silica and the rubber matrix resulted from SA-intermediated linkages. Significantly improved dispersion of silica by virtue of the interactions between silica and SA was found. Formation of zinc disorbate during compounding of composites was confirmed. The effects of SA content on vulcanization behavior, morphology, mechanical properties and abrasion loss of composites were studied. Significantly improved mechanical properties of SA-modified SBR/silica composites were demonstrated. Changes in vulcanization behavior, morphology and performance were correlated with the interactions between silica and SA and the largely improved dispersion of silica. Polymer Journal (2010) 42, 319-326; doi:10.1038/pj.2010.4; published online 17 February 2010