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对Nd(P_(204))_3-Al(i-Bu)_3-CCl_4催化体系在60℃加氢汽油中聚合甲基丙烯酸甲酯进行了详细研究。结果表明,催化剂的制备方法对其催化活性影响很大。与Nd(P_(204))_3-Al(i-Bu)_3二元催化体系相比,催化剂的聚合活性大为加强。Al/Nd=7,CCl_4/Nd=4时,催化体系的活性最大。聚合所得的PMMA间同结构含量在75％左右,烷基铝与钕化物摩尔比、CCl_4/Nd摩尔比对聚合物的立构规整性无明显影响。聚合速度对单体浓度呈零级关系,对催化剂浓度呈一级关系,聚合反应活化能为45·69kJ/mol,聚合机理是配位自由基型聚合机理。
The polymerization of Nd (P_ (204)) _3-Al (i-Bu) _3-CCl_4 catalytic system in 60 ℃ hydrogenated gasoline was studied in detail. The results show that the preparation of catalyst has a great influence on its catalytic activity. Compared with Nd (P_ (204)) _3-Al (i-Bu) _3 binary catalytic system, the polymerization activity of the catalyst is greatly enhanced. Al / Nd = 7, CCl_4 / Nd = 4, the catalytic activity of the largest system. The syndiotactic structure of PMMA obtained by polymerization was about 75%. The mole ratio of aluminum alkyl to neodymium and the molar ratio of CCl 4 / Nd had no significant effect on the tacticity of the polymer. The polymerization rate showed a zero-order relationship with the monomer concentration and a first-order relationship with the catalyst concentration. The activation energy of the polymerization reaction was 45.69 kJ / mol and the polymerization mechanism was coordination radical polymerization.