AbstractThe effect of network density on pyrolysis of polymers and copolymers of styrene, divinylbenzene, and trivinylbenzene was studied over a wide range of temperature. Thermal stability of polymers and size of carbon residues increased with crosslink concentration as volatilization rates declined. Rate of gas evolution was dependent on particle size, but was unaffected by catalyst content and moderate pressure changes. The results indicate extensive alteration of monomer units, possibly by a hydrogen transfer process which favors carbon formation rather than vaporization.