Improved Silica Dispersibility in Silica-rubber Compounds for a Tire Tread by Using an Itaconic Acid-based Polymeric Dispersant

Abstract

Silica dispersibility in a silica-rubber compound is an important factor determining the braking performance, wear resistance, and rolling resistance of an automobile tire tread. In this study, a poly(itaconic acid-co-acrylamide) (IA-co-AAM) dispersant was synthesized by the copolymerization of IA with AAM as a novel silica dispersant for a wet masterbatch (WMB) system. We confirmed the improved silica dispersibility in the silica-rubber compounds via a rubber process analyzer (RPA) and Mooney viscometer (MV). Based on the MV measurements, the values of MV for the silica-SBR compounds using the dispersant decreased by 30 % compared to those in the absence of the dispersant. This showed a positive effect on the rubber processing workability of the silica-SBR compounds. We also evaluated the dynamic viscoelastic properties of the compounds via a dynamic mechanical analyzer (DMA) and found that the rolling resistance of the compounds for the tire tread area also improved.