镍顺丁橡胶分子量控制

Molecular weight regulation of cis 1,4 polybutadiene with nickel catalytic system

本文分别就Ｎｉ（ｎａｐｈ）２ —Ａｌ（ｉ － Ｂｕ）３ —（ＢＦ３·ＯＥｔ２ ＋ ＲＯＲ） 、Ｎｉ（ｎａｐｈ）２ —Ａｌ（ｉ－ Ｂｕ）３ —（ＢＦ３·ＯＥｔ２ ＋ ＲＯＨ） 体系中聚合条件对催化活性及聚合物分子量的影响关系进行了对比，同时还比较了加醚体系、加醇体系的聚合动力学参数。实验结果表明，同稀硼单加的传统体系相比较而言，醚体系具有稳定的分子量控制能力。醚在体系中起着稳定活性中心的作用。该体系适于质量稳定的中门尼顺丁胶的生产。辛醇体系能够很灵敏地从低到高调节聚合物的分子量。高分子量可控制在门尼粘度为８５ ±５ 之间，有利于高门尼充油顺丁胶的合成；低分子量最小可调至［η］ ＝ ０ ．５ｄｌ／ｇ 。这是稀硼单加体系、醚体系不及之处。由于辛醇的作用，通过Ａｌ／Ｂ 比的改变，顺丁胶特性粘数可在０ ．５ ～５ ．０ｄｌ／ｇ 之间很宽范围内调变。醇或醚类的加入均对聚合物分子量分布、微观结构影响不大。

The behavior of butadiene polymerization with Ni(naph) 2(Ni)—Al(i-Bu) 3(Al)—BF 3·OEt 2(B)—ROR、Ni(naph) 2(Ni)—Al(i-Bu) 3(Al)—BF 3·OEt 2(B)—ROH catalytic system were investigated in the present work.The effects of polymerization conditions on the catalytic activity、the molecular weight as well as the kinetics parameter of two catalytic system were examined. In ROR cataltic system,the results revealed that the molecular weight of polymer could be controlled steadily in comparison with the traditional catalytic system.The funcition of ROR was to increase the stability of acive centers.The system was suitable for preapring the middle-mooney BR. The results revealed that the molecular weight of polymer could be sensitively adjusted from low to high by the addtion of ROH.While the maxinum value of Mooney was 85±5,prepared for high-Money OEBR,the lowest value of the intrinsic viscosity reached 0.5dl/g.This was better than both the traditional cataytic system and the catalytic system containing ROR component.As the result of the effect of ROH,the intrinsic viscosity were effectively changed from 0.5～5dl/g via the variation of Al/B mole ration. The moleccular weight distribution and the microstructurd wiere little influenced by the addition of ROR or ROH.