ABSTRACT:A new polymeric peroxycarbamate (PPC), having a substituted cycloaliphatic moiety, was synthesized using the corresponding diisocyanate and a dihydroperoxide. The thermal decomposition kinetics of this PPC were studied in 1,4-dioxane solution at 80, 90, and I00°C. The decomposition reaction was found to proceed according to first order kinetics with activation energy of 125 kJ mo! -1 . Furthermore, this PPC was used to initiate the bulk polymerization of methylstyrene at 80°C and shown to be an effective initiator with negligible chain transfer to the initiator.