Department of Polymeric Materials and Engineering, Faculty of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, China.
Magn Reson Chem. 2012 May;50(5):372-8. doi: 10.1002/mrc.3811. Epub 2012 Apr 12.
4-Methacryloyl-2,2,6,6-tetramethyl-piperidine (MTMP) was applied as reactive hindered amine piperidine. Photo-induced copolymerization of methyl methacrylate (MMA, M(1)) with MTMP (M(2)) was carried out in benzene solution at ambient temperature. The reactivity ratios for these monomers were measured by running a series of reactions at various feed ratios of initial monomers, and the monomer incorporation into copolymer was determined using (1)H NMR. Reactivity ratios of the MMA/MTMP system were measured to be r(1)= 0.37 and r(2)= 1.14 from extended Kelen-Tüdos method. The results show that monomer MTMP prefers homopolymerization to copolymerization in the system, whereas monomer MMA prefers copolymerization to homopolymerization. Sequence structures of the MMA/MTMP copolymers were characterized using (1)H NMR. The results show that the sequence structure for the main chain of the MMA/MTMP copolymers is mainly composed of a syndiotactic configuration, only with a little heterotactic configuration. Three kinds of the sequences of rr, rr', and lr' in the syndiotactic configuration are found. The sequence-length distribution in the MMA/MTMP copolymers is also obtained. For f(1)= 0.2, the monomer unit of MMA is mostly separated by MTMP units, and for f(1)= 0.6, the alternating tendency prevails and a large number of mono-sequences are formed; further up to f(1)= 0.8, the monomer unit of MTMP with the sequence of one unit is interspersed among the chain of MMA.
4-甲丙烯酰基-2,2,6,6-四甲基哌啶（MTMP）用作反应性受阻胺哌啶。在环境温度下，将甲基丙烯酸甲酯（MMA，M（1））与 MTMP（M（2））在苯溶液中进行光诱导共聚。通过在各种初始单体进料比下进行一系列反应来测量这些单体的竞聚率，并使用（1）H NMR 确定单体在共聚物中的掺入量。通过扩展的 Kelen-Tüdos 方法，测量 MMA/MTMP 体系的竞聚率为 r（1）=0.37 和 r（2）=1.14。结果表明，在该体系中，单体 MTMP 更倾向于均聚而不是共聚，而单体 MMA 更倾向于共聚而不是均聚。使用（1）H NMR 对 MMA/MTMP 共聚物的序列结构进行了表征。结果表明，MMA/MTMP 共聚物主链的序列结构主要由间同立构组成，只有少量的间规立构。发现了间同立构中 rr、rr'和 lr'三种序列。还获得了 MMA/MTMP 共聚物中的序列长度分布。对于 f（1）=0.2，MMA 的单体单元主要由 MTMP 单元隔开，对于 f（1）=0.6，交替趋势占主导地位并形成大量的单序列；进一步增加到 f（1）=0.8，具有一个单元序列的 MTMP 单体单元穿插在 MMA 的链中。
