| 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 by 1H NMR and 13C NMR techniques.The copolymer（EMMA-b） of ethylene and methyl methacrylate,produced by radical polymerization,also experienced the corresponding characterization.According to the 1H 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 the 13C 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. |