亚磷酸酯化合物对镍系催化剂催化丁二烯聚合活性及产物支化结构的影响

Effect of phosphite compound on polymerization activity of butadiene catalyzed with nickel-based catalyst and branching structure of products

在丁二烯聚合的Ni（naph）2-Al（i-Bu）3-BF3·OEt2（简称Ni-Al-B）催化体系中引入第4组分三壬基苯基亚磷酸酯（简称P）,考察了P/B（摩尔比）、Al/B（摩尔比,含P体系）对丁二烯聚合活性和聚合产物结构的影响,并用傅里叶变换红外光谱、凝胶渗透色谱（GPC）和GPC-激光光散射仪-黏度计在线联用系统对聚合物的相对分子质量、微观结构及支化结构等进行了表征。结果表明,当P/B不大于0.03、Al/B为0.5~1.0时,单体转化率均达到85%以上;聚合物的相对分子质量可通过改变P/B或Al/B进行调节;P的引入对聚合产物的高顺式1,4-结构含量没有明显的影响,聚合产物中高相对分子质量级分支化程度较不加入P时明显提高,聚合物溶液的剪切黏度呈升高趋势。

The forth component trisnonylphenyl phosphite（ simplified as P） was introduced into Ni（ naph）2-Al（ i-Bu）3-BF3·OEt2（ simplified as NiAl-B） catalyst system,and the effect of P / B（ mole ratio）,Al / B（ mole ratio,containing P system） on polymerization activity of butadiene and products structure were investigated. The relative molecular mass,microstructure and branching structure of the polymer were characterized by Fourier transform infrared spectroscopy,gel permeation chromatography（ GPC） and GPC-laser light scattering apparatus-viscometer on-line coupled system. The results showed that the butadiene monomer conversion could reach more than 85% when P / B（ mole ratio） was lower than 0. 03 and Al / B（ mole ratio） was in the range of0. 5- 1. 0. The relative molecular mass of the polybutadiene could be adjusted by change of P / B（ mole ratio） or Al / B（ mole ratio）. The introduction of P had no obvious effect on the content of high cis-1,4-unit. Compared with the system without P,when P was introduced into Ni-Al-B catalyst system, the branching degree of polybutadiene in the fraction of higher relative molecular mass improved significantly,and the shear viscosity of the polymer solution showed an increasing trend.