Effect of functional groups on the thermal degradation of copolymers

被引:10
|
作者
Shibasaki, Y [1 ]
Yang, M [1 ]
Sun, L [1 ]
机构
[1] Saitama Univ, Fac Sci, Dept Chem, Urawa, Saitama 3388570, Japan
关键词
thermal degradation mechanism; copolymers; styrene; methacrylonitrile; alpha-methylstyrene; flash pyrolysis; thermogravimetry;
D O I
10.1002/pat.184
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Thermal degradation mechanisms of the copolymers of styrene (St) with methacrylonitrile (MAN) and alpha-methylstyrene (alphaMSt) 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 alpha-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 alpha-position of monomer unit strictly hindered the back biting reaction. The role of functional groups on the thermal degradation energies of main chain (Q(C-C)), apparent activation energies (DeltaE(a)) obtained by Ozawa's method from the TG curves at various heating rates. Effect of chemical reactivity of - Cequivalent toN group in MAN unit on the thermal degradation was clarified by the controlled rate thermogravimetry (CRTG). Copyright (C) 2002 John Wiley Sons, Ltd.
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页码:260 / 268
页数:9
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