Effect of functional groups on the thermal degradation of copolymers
作者：Yoshio Shibasaki, Min Yang, Ling Sun · 发表于：Polymers for Advanced Technologies · 年份：2002 · DOI：10.1002/pat.184 · 被引用次数：14 · 研究领域：Thermal and Kinetic Analysis、Polymer crystallization and properties、Polymer Nanocomposites and Properties
Abstract Thermal degradation mechanisms of the copolymers of styrene (St) with methacrylonitrile (MAN) and α‐methylstyrene (αMSt) were studied by pyrolysis gas chromatography (Py‐GC) and thermogravimetry (TG). Thermal degradation of vinyl polymers in flash pyrolysis proceeded mainly in the competition between depolymerization and back biting reaction caused by abstraction of H atom at α‐position in pen‐penultimate unit. Monomer molecules were regenerated by depolymerization, and dimer, trimer and ologomers were produced by back biting reaction. Methyl groups at α‐position of monomer unit strictly hindered the back biting reaction. The role of functional groups on the thermal degradation was elucidated on the basis of bond dissociation energiesof main chain (Q CC ), apparent activation energies(ΔE a ) obtained by Ozawa's method from the TGcurves at various heating rates. Effect of chemical reactivity of C≡N group in MAN unit on the thermal degradation was clarified by the controlled rate thermogravimetry (CRTG). Copyright © 2002 John Wiley & Sons, Ltd.