1989 Volume 17 Issue 2 Pages 77-85
Chemorheology is the best means to elucidate the degradation mechanism of cross-linked polymer at its initial stage. Most of chemorheological research which have been carried out all this while are those related to the scission mechanism of main-chains. The paper deals with the scission mechanism of crosslink site of crosslinked polymers which case is very rare. Polyurethane vulcanizates are exposed in N2 gas at high temperatures, 383, 393 and 403K, and in the solution of n-BuNH2/DMSO at 298, 303 and 308K. Chemical relaxation curves thus obtained were found to be consistent with theoretical prediction by Tobolsky. The scission mechanism of cross-link sites of polyurethane vulcanizates was also studied by the swelling, GPC, and IR measurements.