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镍系催化丁二烯聚合
POLYMERIZATION OF BUTADIENE WITH NICKEL CATALYST SYSTEM
【摘要】 我国镍系顺丁橡胶(BR)生产采用以加氢汽油为溶剂的Ni(naph)_2-Al(i-Bu)_3-BF_3·OEt_2(简称Ni-Al-B)催化体系。聚合活性与Al/B(摩尔比)密切相关,Al/B值又是调节BR分子量的关键参数。催化活性中心上镍的价态分别为N1(0)和Ni(I),聚合反应的表观活化能为E_a[Ni(0)]<E_a[Ni(I)]。AlR_2F也是组成活性中心配合物的结构单元。催化活性表现有低温聚合依时性的稳定性和高温聚合依时性的不稳定性的规律。体系中添加醇、酯类可拓宽Al/B值的调节范围,制得5的BR,其1,4含量高于96%。
【Abstract】 Synthesis of 1,4-polybutadiene with nickel catalyst system Ni(naph)2-Al(i-Bu)3-BF3OEt2 in hydrogenated gasoline as solvent has been carried out domesticallv for manv vears.The catalvtic activity depends closely upon the molar ratio of Al/B which is also a key parameter adjusting the molecular weight of polybutadiene. The active valency state of nickel is Ni(I) or Ni(0) in the active center complexes.The overall activation energy of polymerization showS Ea(Ni(0))<Ea(Ni(I)).The structural unit AlR2F is also a constituent part of the active center complexes. It has shown that the time dependenec of catalytic activity is stable at lower temperatures and u nstable at higher tem peratures. The effective range of Al/B value could be broadened if several sorts of alcohol and ester are added into the system. The 1,4-polybutadiene obtained has ML 85)±5 and it’s content of 1,4-chain unit is as high as 96%.
【Key words】 Polymerization of butadiene; Nickel catalyst system; Active center;
- 【文献出处】 化学反应工程与工艺 ,CHEMICAL REACTION ENGINEERING AND TECHNOLOGY , 编辑部邮箱 ,1994年01期
- 【分类号】TQ325.1
- 【被引频次】4
- 【下载频次】112