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机构地区:[1]中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室,武汉430071
出 处:《波谱学杂志》1997年第4期307-312,共6页Chinese Journal of Magnetic Resonance
基 金:国家科委国家基础性研究重大关键项目;"高分子凝聚态的基本物理问题研究"基金
摘 要:用核弛豫研究了溶液中甲基丙烯酸甲酯-萘乙烯共聚物体系中高分子链间的凝聚态结构.通过对溶液中甲基丙烯酸甲酯-萘乙烯共聚物的变温13CNMR自旋-晶格弛豫的研究,发现此体系具有类似小分子在溶液中的弛豫特性.变温1HNMR自旋-自旅弛豫呈现出双指数特性,弛豫快的部分随温度升高而减少对应于聚合物链间凝聚缠结的解缠,当温度继续升高时,主链的这种组分又开始增加,说明主链中形成新的缠结.研究结果还表明,在这种共聚物中,例基萘环的叠加较少.The cohesive interaction among polymer chains in methyl methacrylate - naphthyl ethylene copoly-mer solution was studied by NMR relaxation. 13C NMR relaxation times of methyl methacrylate -naphthyl ethylene copolynler in its good solvent deuteriochloroform were measured at different temper-atures. The T1 vaJues of individual carbon atoms of methyl methacrylate - naphthyl ethylene copolymer in solution increase as the temperature increases, which is characteristic of the NMR relaxation of small molecules in solution. 1H NMR transverse relaxation of protons attached to carbons of this copolymer shows biexponential behavior, which corresponds to two states of the copolymer. The fast relaxating conponent decreases with increasing temperature, corresponding to the disentanglement of cohesional entangled chains. When tempreature becomes even higher, this component of the main chain start to increase again, this shows that new entanglements occurs among copolymer main chains. Results also show that in this copolymer system, the interlocking interaction of the side group- naphthyl rings is scarce.
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