SYNTHESIS AND PROPERTIES OF POLYURETHANE MACROAZO INITIATORS

The synthesis of a typical polyurethane macroazo initiator (PUMAI) bas ed on 2,2'-azobis(2-cyanopropanol) (ACP), alpha, omega-hydroxy polycap rolactone (PCL) and 4,4'-methylene diphenyl diisocyanate (MDI) occurs in a two stage polycondensation procedure. Kinetics of the reaction be tween ACP and a monoisocyanate (para-tolylisocyanate, p-TI), and the r eaction between MDI and PCL were carried out. Reaction rates were dete rmined by a suggested kinetic model. Thermal decomposition of PUMAI co mpared to other azo initiators has been investigated. The kinetic and thermal parameters associated with these initiators were determined by thermogravimetric analysis (TGA).