The effect of HCPX and EC as a stitching agent during thermal vulcanization of modified isoprene rubber (SKI-3- PVA) 80:20 in the presence of zinc oxide was studied. Studies of structural changes occurring in vulcanizates based on SKI-3-PVA under the influence of heating have been carried out. Based on the data of IR spectroscopy and the gel fraction, the rate of reactions with hexachloroparaxylenes (HCPX) between the studied low molecular weight compounds was studied. Considerations are made about the nature of the vulcanization action of the studied structuring systems and the features of their influence on the parameter of the spatial network and the physical and mechanical properties of vulcanizates. The effect of heating time on the content of total and combined chlorine in samples containing HCPX and ZnO was studied. The number of stitched HCPX molecules per cross-link was calculated