镍系催化丁二烯聚合

POLYMERIZATION OF BUTADIENE WITH NICKEL CATALYST SYSTEM

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％。

Synthesis of 1,4-polybutadiene with nickel catalyst system Ni(naph)_2-Al(i-Bu)_3-BF_3OEt_2 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 E_a(Ni(0))<E_a(Ni(I)).The structural unit AlR_2F 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%.