Xanthate-Mediated Radical Polymerization of N-Vinylpyrrolidone in Fluoroalcohols for Simultaneous Control of Molecular Weight and Tacticity
Xanthate-Mediated Radical Polymerization of N-Vinylpyrrolidone in Fluoroalcohols for Simultaneous Control of Molecular Weight and Tacticity
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DOI：
10.1021/ma0515230
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发表时间：
2005-11
期刊：
影响因子：
5.5
通讯作者：
Decheng Wan;K. Satoh;M. Kamigaito;Y. Okamoto
中科院分区：
文献类型：
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作者：
Decheng Wan;K. Satoh;M. Kamigaito;Y. Okamoto
首次报道了自由基聚合过程中聚n -乙烯基吡咯烷酮的弹性和分子量的同时控制。为控制分子量，采用（o -乙基黄原基甲基）苯和[1-（o -乙基黄原基）乙基]苯黄原药作为RAFT/MADIX链转移剂进行n -乙烯基吡啶酮（NVP）自由基聚合。两者均可导致可控/活自由基聚合，且在最优条件下，后者表现出更高的链转移能力；当分子量达到26 700时，分子量分布为1.36。在20 ~ 120°C和不同浓度的CTA下研究了聚合反应。所有的聚合反应都表现出与CTA浓度和温度有关的诱导期和速率延迟。为了控制阳离子性，聚合是在氟醇中通过常规自由基法进行的，没有cta来得到共规聚合物。聚合物的粘性取决于…
The simultaneous control of the tacticity and molecular weight of poly(N-vinylpyrrolidone) during radical polymerization is reported for the first time. For molecular weight control, xanthates of (O-ethylxanthylmethyl)benzene and [1-(O-ethylxanthyl)ethyl]benzene were used as RAFT/MADIX chain transfer agents (CTAs) for the radical polymerization of N-vinylpyrrolidone (NVP). Both led to a controlled/living radical polymerization, and the latter showed higher chain transfer ability under the optimal conditions; the molecular weight distribution was 1.36 when the molecular weight was up to 26 700. The polymerization was studied between 20 and 120 °C and at various concentrations of CTA. All the polymerizations showed an induction period and rate retardation dependent on both the concentration of CTA and temperature. For tacticity control, the polymerization was carried out in fluoroalcohols via a conventional radical process without CTAs to give syndiotactic polymers. The polymer tacticity was dependent on th...