Electron spin resonance studies of reversible addition-fragmentation transfer polymerisation
Electron spin resonance studies of reversible addition-fragmentation transfer polymerisation
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DOI：
10.1002/masy.200390059
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发表时间：
2003-03
影响因子：
--
通讯作者：
F. Calitz;M. Tonge;R. Sanderson
中科院分区：
文献类型：
--
作者：
F. Calitz;M. Tonge;R. Sanderson
研究了异丙基二硫代苯甲酸异丙酯(RAFT)存在下的苯乙烯聚合反应。用电子自旋共振谱测定了中间自由基物种浓度随温度和反应物相对初始量的变化规律。发现中间自由基浓度远低于Barner-Kosollik等人的研究预测[Barner-Kosollik，C.；Quinn，J.F.；Morsley，D.R.；Davis，T.P.J.Polym。SCI。A部分：多项式。化学。2001，39,1353]，但与Hawthorne等人[Hawthorne，D.G.；Moad，G.；Rizzardo，E.；Tang，S.H.Macromoleculs1999，32,5457]和Kwak等人[Kwak，Y.；Goto，A.；Tsujii，Y.；Murata，Y.；Komatsu，K.；Fukuda，T.Macromoles 2002，35,3026]的观察结果一致。在大量引发剂存在后很长时间内观察到中间自由基信号，在较长反应时间的ESR谱中出现额外的信号。
The polymerisation of styrene in the presence of cumyl dithiobenzoate (RAFT agent) was studied. Electron spin resonance spectroscopy was used to determine the time-dependence of the concentrations of the intermediate radical species, as a function of temperature and relative initial amounts of reactants. The intermediate radical concentration was found to be much lower than predicted by the studies of Barner-Kowollik et al.[Barner-Kowollik, C.; Quinn, J. F.; Morsley, D. R.; Davis, T. P. J. Polym. Sci. Part A: Polym. Chem. 2001, 39, 1353], but consistent with that observed by Hawthorne et al.[Hawthorne, D. G.; Moad, G.; Rizzardo, E.; Thang, S. H. Macromolecules 1999, 32, 5457] and Kwak et al.[Kwak, Y.; Goto, A.; Tsujii, Y.; Murata, Y.; Komatsu, K.; Fukuda, T. Macromolecules 2002, 35, 3026] Several observations that are not consistent with the current RAFT model were made. Intermediate radical signals were observed long after a significant amount of initiator remained and an extra signal appeared in the ESR spectrum at longer reaction times.