氢气对钼系催化剂合成1,2-聚丁二烯的影响

Effect of hydrogen gas on synthesis of 1,2-polybutadiene with molybdenum catalyst system

在氢气存在下,以辛醇取代的五氯化钼及间甲酚取代的三异丁基铝为催化剂引发丁二烯配位聚合,研究了氢气加入量及加入方式对1,2-聚丁二烯相对分子质量及其分布、微观结构、剪切黏度、门尼黏度以及硫化胶物理机械性能的影响。结果表明,随着氢气加入量的增加,聚合物相对分子质量降低,分布变宽。当氢气压力大于0.40 MPa时,随着氢气加入量的增加,聚合物相对分子质量及其分布的变化趋缓,其中连续加入氢气的方式对聚合物相对分子质量及其分布的调节作用较一次性加入方式要好。加入氢气后所得聚合物的1,2-结构含量有所降低,聚合物溶液的剪切黏度下降明显,生胶门尼黏度略有增加。当氢气压力小于0.80 MPa时,聚合物硫化胶的扯断伸长率和永久变形降低,其他物理机械性能基本不受影响。

The butadiene was coordinatively polymerized with octanol replaced molybdenum pentachloride and mesormethyl phenol replaced triisobutyl aluminium as catalyst and hydrogen gas as relative molecular mass modifier, and the effects of amount and addition methods of hydrogen gas on relative molecular mass and its distribution , microstructure, shear viscosity, Mooney viscosity and mechanical properies of 1,2-polybutadiene（ 1,2-PB ） were studied. The results showed that the relative molecular mass of the 1,2-PB decreased and its distribution became wider with the increase of hydrogen gas amount. When pressure of the hydrogen gas was more tnan 0.40 MPa, the changes of the relative molecular mass and its distribution of the 1,2-PB were not obvious with the increase of hydrogen gas amount. However, the adjusting function of hydrogen gas by stepwise addition for the relative molecular mass and its distribution of the 1,2-PB was better than that by one-off addition. The 1,2-unit content of 1,2-PB decreased slightly, the shear viscosity declined obviously and the Mooney viscosity increased slightly after hydrogen gas was added. The elongation at break and permanent set of the 1,2-PB vulcanizates decreased when the hydrogen gas pressure was less than 0. 80 MPa, and other mechanical properties had not be affected obviously.