STUDIES OF PEROXIDE CURING OF cis-1,4-POLYISOPRENE/DIALLYL PHTHALATE BLENDS BY SPECTROSCOPIC TECHNIQUES

Peroxide curing of cis-1.4-polyisoprene/diallyl plithalate blends was studied by the analytical techniques of equilibrium swelling, differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR), and solid-state nuclear magnetic resonance (NMR). Although the overall curing kinetics are controlled by the peroxide decomposition rate, the addition of a coagent into the rubber matrix catalyzes the curing reactions. The increase in peroxide and coagent concentrations in the blend results in a decrease in 72 relaxation times, which is caused by restricted segmental mobility due to the increase ill crosslink density. It is suggested that phase separated coagent domains are chemically bound with the rubber matrix, providing the decrease in segmental mobility.