摘要
本文用NMR方法研究了聚甲基丙烯酸锡酯样品(PTMTM、PTETM、PTBTM)中锡原子的配位形式,结果表明:处于不同状态的样品,其锡原子的配位形式不尽相同,样品溶解于CDCl_3时,锡原子仅以四配位形式存在,固态时则存在两种不同的配位形式:即四配位形式和五配位形式,然而随着酯基基团的增大,逐渐以四配位形式为主,该结论与国产红外光谱法所得结论一致。本文还用NMR方法对各基团运动情况进行了初探。发现锡的取代及其配位形式和酯基基团的大小皆不影响高分子主链的α-CH_3的运动,但酯基基团的内旋转运动因单元内Sn与C=0的顺式配位而减弱,同时.NMR参数还揭示了较长酯烷基侧链链段运动情况。
The coordination forms of tin atoms on poly (tri-alkyltin methacsylate) s are analysed with NMR method. Analysis results reveal that the coordination forms of tin atoms appear different in various states. As samples are dissolved in COCl_3, only one type of coordination form exists that is reffered to four-coordinated form, while in solid state, there're two different types of coordination forms reffered to four-& five-coordinated forms reapectinvely, neverthless, with the increases of the size of the carboxylates, tin atoms tend to exist mainly in the shape of four-coordinated structure. Results from NMR are in good conformity with those from IR.Wity NMR method, we also make a preliminary exploration on the motions of different groups in samples. It indicates that the motions of the main chain & α-CH_3 are not influenced by the tin substitute, the coordination forms of tin atoms & size of the tin ester groups, but the intraunit cis-coordination between tin atom & carboxyl weaken the internal rotation of ester alkyl groups. In this investigetion, NMR data also reveals the segmental motions along ester alkyl side-chain in samples.
出处
《功能高分子学报》
CAS
CSCD
1991年第4期259-264,共6页
Journal of Functional Polymers
关键词
聚甲基
丙烯酸锡酯
配位形式
poly(tri-alkyltin methacrylate)s, ^(13)C, ^(119)Sn-NMR, coordination form, molecular motion.
