丙烯酸甲酯/4-丙烯酰胺基-2,2,6,6-四甲基哌啶光共聚合体系的竞聚率和序列分布研究  

THE REACTIVITY RATIOS AND SEQUENCE-LENGTH DISTRIBUTION OF PHOTO-INDUCED COPOLYMERIZATION OF MA AND AATP IN SOLUTION

作　　者：刘晓暄[1] 邓湘华[1] 张婷[1] 吴光国[1] 

机构地区：[1]汕头大学理学院化学系,汕头515063

出　　处：《高分子学报》2006年第1期118-123,共6页Acta Polymerica Sinica

摘　　要：以丙烯酸甲酯(MA,M1)和4-丙烯酰胺基-2,2,6,6-四甲基哌啶(AATP,M2)溶液光共聚合体系为研究对象,采用1H-NMR手段测定了MA/AATP共聚物的组成,用Mayo-Lewis积分法和扩展Kelen-Tüdos方法计算的竞聚率分别为0.88<r1<0.95与0.43<r2<0.69和r1=0.90和r2=0.50.研究结果表明,在MA/AATP光共聚体系中,两种单体的竞聚率均小于1.0,且在f1=0.73处有一恒分共聚点,属于非理想共聚体系.由所得竞聚率计算了MA/AATP共聚物主链结构的序列长度分布f2=0.7时,MA序列长度为1的含量占80.0%,MA单元基本上被AATP单元分隔开;f2=0.5时,两种单元体在共聚物主链上交替出现;f2=0.1时,AATP单元序列长度为1的含量占95.0%,AATP主要以单个单元分布在MA链中.The photo-induced copolymerization of methyl acrylate （MA, MI ） and 4-acrylamido-2, 2, 6, 6- tetramethyl-piperidine （AATP, M2 ） in pyridine solutions was studied. The composition of MA and AATP copolymers was determined with ^1H-NMR method. According to the composition of poly （MA-co-AATP）, the reactivity ratios of MA/AATP copolymerization system were calculated as 0.88 〈 r, 〈 0.95 and 0.43 〈 r2 〈 0.69 by the Mayo-Lewis method,as same as r1= 0.90 and r2= 0.50 by the extended Kelen-Ttidos method. The results showed that the reactivity ratios of both MA and AATP monomer were less than 1, as r1 〈 1 and r2 〈 1, and the performance of MA/ AATP copolymerization system is non-ideal azeotropic copolymerization having an azeotropic point at f1 = 0.73. On the basis of the reactivity ratios of two monomers, the sequence-length distribution in the MA/AATP copolymers was obtained. For f2 = 0. 7, the probability of the MA sequence of 1 unit in the copolymer chain is 80.0 %, the monomer unit of MA is mostly separated by the sequence of AATP; and for f2 = 0.5, the alternating tendency prevails and a large number of mono-sequences are formed; and in the case of f2 = 0.1, the probability of the AATP sequence of 1 unit in the copolymer chain is 95.0 %, the monomer unit of AATP is individually separated in the chain of MA.

关 键 词：AATP 光共聚合 竞聚率 序列分 

分 类 号：O631.5[理学—高分子化学]