Rubber-Thermoplastic Compositions. Part III. Predicting Elastic Moduli of Melt Mixed Rubber-Plastic Blends

Abstract

Abstract Blends prepared by mixing rubbers with plastics in the molten state have been known and used for a number of years. The stiffness of such blends vary widely with both the proportions of rubber to plastic and with material selection, even at equivalent rubber to plastic proportions. This report describes correlations between blend stiffness and the properties of the individual blend components. Dynamic shear modulus G′, determined by torsion pendulum measurements, was used to characterize the stiffnesses of the blends. Values of G′ were related to the moduli of the hard and soft (plastic and rubber) phases, G′H and G′S, and the volume fraction of plastic ϕH through a single adjustable parameter by means of a recently proposed relationship. The adjustable parameter was then correlated with other properties of the blend components. In contrast with the work reported in the first two papers of this series, this report is on compositions in which the rubber is not crosslinked.