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作 者:李静[1] 许风玲[2] 谢美然[2] 张惠平[1] 余亦华[1]
机构地区:[1]上海市功能磁共振成像重点实验室 华东师范大学物理系,上海200062 [2]华东师范大学化学系,上海200062
出 处:《波谱学杂志》2008年第1期11-17,共7页Chinese Journal of Magnetic Resonance
基 金:国家自然科学基金资助项目(20474018)
摘 要:对由原子转移自由基聚合(ATRP)方法得到的具有"活性"聚合特征的对-氯苯乙烯(S)和丙烯酸甲酯(M)梯度共聚物结构进行了表征.通过1H、13C核磁共振(NMR)方法和对羰基13C峰峰面积的拟合积分研究了该共聚物的单体以及以M为中心的三元组序列结构的组成含量随转化率的变化.研究结果表明:共聚物链中S和M单体含量随着转化率的增加分别表现出减小和增大的变化趋势;三元组序列结构的含量变化中,SMS和MMM分别呈现出单调下降和上升的变化,而SMM/MMS则随着转化率的增加达到一个最大值,然后呈现下降趋势.本文还尝试运用了以M为中心的五元组序列结构对羰基13C峰峰面积进行更精确的拟合积分,其拟合峰面积的计算结果显示了与上述三元组序列结果相同的变化规律.Gadient copolymers of p-chlorostyrene (S) and methyl acrylate (M) were polymerized via atom transfer radical polymerization (ATRP). The microstructures of the copolymers were characterized by a combination of NMR spectroscopy and peak modeling of carbonyl laC peaks corresponding to different M-centered triads in sequence of molecular chain. The results showed that, with increasing conversion rates, the monomer contents of S and M in the copolymers decreased and increased gradually, respectively. The contents of M-centered triads showed different trends of changes with conversion rate. M-centered triads SMS and MMM decreased or increased monotonously, respectively, with increasing conversion rate, but the SMM/MMS ratio increased to a maximal value when the conversion rate reached around 80 % and decreased afterwards. The M-centered pentad sequences showed similar changes in contents with conversion rate as the M-centered triads sequence.
关 键 词:核磁共振 结构表征 三元组序列结构 对-氯苯乙烯和丙烯酸甲酯梯度共聚物
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