Kinetics of Sulfur Vulcanization of Isoprene Rubber with Polymer Sulfur

Abstract

The work is devoted to the study of the features of sulfur vulcanization (SV) of isoprene rubber (SKI-3) with polymer sulfur (PS). The rubber compound of the truck tire breaker contained 4,8 wt.h. PS of the Kristex OT-20 brand per 100 wt.h. SKI-3 and two sulfenamide accelerators with a total content of 1,9 wt.h. The kinetics of the SKI-3 CB was evaluated on the MDR-2000 device by fixing the change in the value of the elastic component S’ of the torque. After processing the data obtained, the following sequential regions of the SV were established: diffusion, diffusion-kinetic, kinetic, transition region and reversion region. Each region, depending on the temperature of the SV, has its own time range of flow and is characterized by its own flow rate. The activation energies of the diffusion of PS in SKI-3, the formation of crosslinking nodes in the main period of SV, as well as the decay of polysulfide bonds in the reversion region are determined. The interpretation of the obtained kinetic characteristics of the SV SKI-3 PS is given.