| Abstract: | The dependence of the dynamic shear modulus of blends of polyvinyl chloride and rubber on the temperature and concentration of the rubber was investigated. For a calculation of a theoretical value of the modulus a formula recently derived by Uemura and Takayanagi was adopted. This formula is based on the assumption of a two-phase system, in which one phase is a continual matrix and the other is discrete spherical particles, and of perfect adhesion between the phases. Most of the theories that clarify the part played by rubber in rubber-modified vitreous materials are based on these assumptions. In most cases we have found a good conformity between the theoretical and experimental values of the modulus. In a certain system with an outstanding impact strength, however, a severe discrepancy has been found. This implies that the present structural explanation of the high impact strengths of two-phase systems is not quite generally applicable. |
