Optimization of properties in a rubber compound containing a ternary polymer blend using response surface methodology

Abstract

In order to find the best combination of three synthetic rubbers, that is, styrene-butadiene rubber (SBR) grade 1712, SBR grade 1721 and high-1,4-cis polybutadiene, that produce a compound with specific end-use properties, a statistical experimental design is proposed in this work. The design consists of ten mixtures containing specific amounts of total styrene and BR content. A number of properties are tested in each mixture, selecting those related to requirements for the tread of a high performance tire: glass transition temperature (Tg), the ratio between the viscous modulus and the elastic modulus (tanδ@60 °C), Mooney viscosity, and the tensile properties. The values obtained for each property are fit to statistically significant models, obtaining the respective response surfaces. These are next used to define a desirable formulation with the optimal ratio of each rubber, and finally the optimized formulation is validated by comparing the experimental and predicted values for each modeled property.