4-丙烯酰氧基-1，2，2，6，6-五甲基哌啶醇酯和甲基丙烯酸甲酯溶液光共聚合的竞聚率和序列分布研究

在紫外光辐照下，采用溶液聚合获得了4-丙烯酰氧基．1，2，2，6，6-五甲基哌啶醇酯（APMP）（M1）和甲基丙烯酸甲酯（MMA）（M2）的共聚物，用’H-NMR测定了单体摩尔比分别为10／90，30／70，50／50，70／30，90／10时的聚合物结构。采用Mayo—Lewis积分法获得体系的竞聚率为0．32〈^〈0．58，0．10〈r2〈0．30；采用扩展Kelen-Ttidos方法计算的竞聚为r1=0．40和r2=0．19。结果表明，APMP与MMA溶液光共聚体系为非理想共聚体系，并且在投料比^=0．62时有一恒分点。根据竞聚率结果获得了APMP与MMA的共聚物主链结构的序列长度分布：f1=0．1时，单个APMP被MMA单元体均匀地隔开;f2=0．5时，APMP和MMA单元体在共聚物主链上的序列分布交替性比较明显。f1=0．7时，MMA主要以单个单元体分布在APMP主链中。

Study on the Reactivity Ratios and Sequence-length Distribution of Photo-induced Copolymerization of APMP and MMA in Solution

The photo-induced copolymerization of 4-acryloyl-2, 2, 6, 6-pentamethyl-piperidine （APMP） （M1 ） and methyl methacrylate （MMA） （M2 ） in benzene solution has been studied. The compositions of APMP/MMA copolymers were determined by ^1H-NMR. According to the composition of poly （APMP-eo-MMA）, the reactivity ratios of APMP/MMA copolymerizatian system are calculated as 0.32 〈 r1 〈0. 58 and 0.10 〈 r2 〈0. 30 by Mayo-Lewis method,as same as rI =0. 40 and r2 = 0. 19 by extending Kelen-Tiidos method. The results have shown that the performance of APMP/ MMA copolymerization system is non-ideal azeotropic copolymerization that has a azeotropie point at f1 = 0. 62. On the basis of the reactivity ratios of two monomers, the sequence-length distribution in the APMP/MMA copolymers is obtained. Forfl = 0. 1, the monomer unit of APMP is mostly separated by the sequence of MMA;and for f1 = 0. 5, the ahernating tendency prevails and a large number of mono-sequences are formed ; and further to f1 = 0. 7, MMA is interspersed with the sequence of 1 unit in the chain of APMP.