EFFECT OF SOLVENT ON RADICAL POLYMERIZATION OF VINYL BENZOATE
EFFECT OF SOLVENT ON RADICAL POLYMERIZATION OF VINYL BENZOATE
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DOI：
10.1002/pol.1978.170160802
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发表时间：
1978-01-01
影响因子：
--
通讯作者：
NOZAKURA, S
中科院分区：
文献类型：
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作者：
KAMACHI, M;SATOH, J;NOZAKURA, S
苯甲酸乙烯酯聚合的绝对速率常数已在各种芳香族溶剂和乙酸乙酯中在30°C下使用间歇照明法测量。绝对速率常数的测定表明，溶剂对苯甲酸乙烯酯聚合速率的影响主要归因于kp值随溶剂的变化，而不是kt值的变化。所用溶剂的 Kp 值按以下顺序增加：苯甲腈 < 苯甲酸乙酯 < 苯甲醚 < 氯苯 < 苯 < 氟苯 < 乙酸乙酯。最大值和最小值之间有八倍的差异。kp 值之间的巨大变化既不是通过溶剂共聚也不是通过链转移到溶剂来解释的，而是通过增长自由基和芳族溶剂之间的可逆络合物形成来解释的。 kp 值与计算出的复合物离域稳定性之间的相关性支持了这一解释。
Absolute rate constants of the vinyl benzoate polymerization have been measured by use of the intermittent illumination method in various aromatic solvents and ethyl acetate at 30°C. The determination of absolute rate constants showed that effects of solvent on the polymerization rate of vinyl benzoate were mainly ascribed to the variation ofkpvalues with solvents rather than that ofktvalues. Thekpvalues for solvents used increased in the order: benzonitrile < ethyl benzoate < anisole < chlorobenzene < benzene < fluorobenzene < ethyl acetate. There was an eightfold difference between the largest and the smallest values The large variation amongkpvalues was explained neither by the copolymerization through solvents nor the chain transfer to solvents, but by a reversible complex formation between the propagating radical and aromatic solvents. This explanation was supported by a correlation betweenkpvalues and calculated delocalization stabilizations for the complexes.