【摘要】 采用核磁共振(1H NMR、13C NMR)技术对由双[N-(2,6-二异丙基苯基)-3-异丙基水杨醛亚胺]镍(Ⅱ)配合物/甲基铝氧烷(Methylaluminoxane,MAO)催化乙烯-甲基丙烯酸甲酯共聚得到的共聚物(EMMA-a)的微观结构和组成进行了详细的分析与表征,同时对自由基聚合制得的乙烯-甲基丙烯酸甲酯共聚物(EMMA-b)作了相应的分析与表征。通过1H NMR数据,计算得到两种共聚物样品中共聚单体甲基丙烯酸甲酯(MMA)的插入率分别为14.10%和10.26%(摩尔百分数)。基于13C NMR数据,分析比较了由配位共聚与自由基共聚所得共聚物样品在微观结构上的区别,结果发现,在共聚物的乙烯链段部分,由配位共聚得到的共聚物样品EMMA-a主要含有甲基型支链,而由自由基共聚所得共聚物样品EMMA-b具有长链型支链。另外,在共聚物的MMA链节部分,EMMA-a中的MMA单元的羰基(C‖O)碳的化学位移为177.27,而EMMA-b中的MMA单元的羰基(C‖O)碳的化学位移为175.96。更多还原

【Abstract】 The microstructure and composition of ethylene and methyl methacrylate copolymer( EMMA-a),obtained with bis [N-( 2,6-diisopropylphenyl)-3-isopropylsalicylaldiminate]-nickel( Ⅱ)/methylaluminoxane( MAO),were fully characterized by1 H NMR and13 C NMR techniques. The copolymer( EMMA-b) of ethylene and methyl methacrylate,produced by radical polymerization,also experienced the corresponding characterization. According to the1 H NMR data,the corporations of the co-unit MMA in the two copolymers were calculated to be 14. 10% and 10. 26%,respectively.Based on the13 C NMR data,the microstructures of the two copolymers were compared. The results showed that in the ethylene co-units,methyl-type branches mainly appeared in the EMMA-a,while long-chain branches were found in the EMMA-b. Besides,in the MMA co-units,the chemical shift of carbon in carbonyl( C ‖O) of EMMA-a was found as 177. 27,while the chemical shift of carbon in carbonyl( C ‖O) of EMMA-b was 175. 96.更多还原