Further discussion on the estimation of primary polymer chain length of vinyl-type network polymers based on the thermal decomposition of azo crosslinks
Further discussion on the estimation of primary polymer chain length of vinyl-type network polymers based on the thermal decomposition of azo crosslinks
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基于偶氮交联热分解的乙烯基型网络聚合物主链长度估算的进一步探讨
DOI：
10.1016/j.polymer.2004.08.015
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发表时间：
2004
期刊：
影响因子：
4.6
通讯作者：
T. Iwata
中科院分区：
文献类型：
--
作者：
A. Matsumoto;K. Kumada;Yoshikatsu Ichiryu;Hiroyuki Aota;K. Shiraki;T. Iwata
在60°C下，将含有两个碳-碳双键和一个偶氮基团的2，2 ′-偶氮双[N-（2-丙烯基）-2-甲基丙酰胺]（APMPA）与苯甲酸乙烯酯（VBz）进行共聚，得到含偶氮基团的VBz/APMPA预聚物或交联聚合物，分别作为可溶性和不溶性聚合物偶氮引发剂。简要讨论了VBz/APMPA（90/10 mol/mol）共聚合的凝胶化过程，以揭示APMPA作为新型交联剂的聚合行为特征。然后，在链转移剂十二烷基硫醇（LM）的存在下，将所得的聚（VBz-co-APMPA）作为预聚物或交联聚合物在高温下热分解，由此，通过偶氮交联键断裂产生的聚合物自由基将与LM发生链转移反应，得到聚合物主链。这将提供一种新的方法来估计乙烯基型网络聚合物的聚合物主链长度，通过在凝胶点处切割网络中的所有交联，如用于推导Stockmayer方程所定义的。
2,2′-Azobis[N-(2-propenyl)-2-methylpropionamide] (APMPA) having two carbon–carbon double bonds and an azo group was copolymerized with vinyl benzoate (VBz) at 60°C, providing an azo groups containing VBz/APMPA prepolymer or crosslinked polymer which acts as a soluble or insoluble polymeric azo initiator, respectively. The gelation in VBz/APMPA (90/10mol/mol) copolymerization was discussed briefly in order to reveal the characteristic polymerization behavior of APMPA as a novel crosslinker. Then, the resulting poly(VBz-co-APMPA)s as prepolymers or crosslinked polymers were thermally decomposed at elevated temperatures in the presence of lauryl mercaptan (LM) as a chain transfer agent; thus, the polymeric radicals generated through the cleavage of azo crosslinks would undergo the chain transfer reaction with LM to give primary polymer chains. This will provide a new approach to estimate the primary polymer chain length of vinyl-type network polymers by cutting all crosslinks in the network at the gel point as defined for the derivation of Stockmayer's equation.