Effect of Plasticization of Isoprene Rubber on the Hardness of its Vulcanizates. Part 2. Contribution of Macromolecular Fractions of Rubber.

Abstract

In this part of the article, the issues of the influence of plasticization of isoprene rubber (SKI-3) on the hardness (H) of the filled TU vulcanizates of its individual fractions are considered. It was assumed that the amount H of vulcanizate SKI-3 consists of the sum of the products of the efficiency of the contribution of each of the rubber fractions to this indicator by its mass fraction. It was found out that depending on the temperature and time of SKI-3 plasticization, the efficiency of the contribution of fractions is varies. The kinetic parameters of the processes of changing the efficiency of the contributions of each of the considered fractions are calculated. As a result, it was found that with a decrease in the MM value of the SKI-3 fractions, the value of the rate constant of change in the index H of filled vulcanizates decreases, and the value of the activation energy increases. It has been found that an increase in the temperature of plasticization contributes to an increase in the value of H-filled vulcanizates of both SKI-3 itself and its fractions, due to an increase in the process of oxidative destruction of macromolecules. It has been established that an increase in the plasticization temperature contributes to an increase in the H value of filled vulcanizates of both isoprene rubber itself and its fractions due to an increase in the process of oxidative degradation of macromolecules.