Thermal decomposition of poly(tert‐butyl N‐vinylcarbamate)

Abstract

AbstractPyrolysis of poly(tert‐butyl N‐vinylcarbamate) at 185–200°C in bulk yields a rigid foam containing cyclic urea units, primary amine units, and a small amount of urea crosslinks. The yield of primary amine units (ca. 13%) and the yields of carbon dioxide (ca. 57%), isobutylene (ca. 57%), and tert‐butanol formed in this reaction indicate that it involves pairwise decomposition of adjacent carbamate units to form cyclic urea units, tert‐butanol, carbon dioxide, and isobutylene. The vinyl amine units are formed from carbamate units that become flanked by urea units. The amounts of amine units and residual carbamate units were determined as a function of degree of pyrolysis by an ion‐exchange technique and agreed with values expected for a random cyclization process. The pyrolyzed polymers are useful as ion‐exchange resins and as rigid foams having good thermal stability.