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研究了烧氧基钼-乙基苯氧基辛氧基铝(Mo-Al)催化合成 1,2-聚丁二烯橡胶的聚合规律和聚合物的微观结构。当Al/Mo=17—40(mol比)时,转化率均能保持在80％以上。可用 Al/Mo值作为调节分子量的手段:Al/Mo 值小于17,[η]随Al/Mo值的增加而升高;Al/Mo=17,则出现峰值;Al/Mo>17,则随Al/Mo值的增加而缓慢下降。聚合温度低于50℃,转化率随聚合温度的升高而增加,50℃时可达90％以上;高于50℃,转化率反而下降。与一般钼体系相比,所得聚合物中1,2-链节的全同立体异构体的序列长度有所增加,约为4.2。
The polymerization rules and the microstructure of 1,2-polybutadiene rubber catalyzed by molybdenum-ethylphenoxyloctyloxy aluminum (Mo-Al) were studied. When Al / Mo = 17-40 (molar ratio), the conversion rate can be maintained at 80% or more. Al / Mo can be used as a means to adjust the molecular weight: Al / Mo value is less than 17, [η] increases with increasing Al / Mo value; Al / Mo = 17, the peak appears; Al / Mo> 17, The Al / Mo value increased slowly and decreased slowly. The polymerization temperature is lower than 50 ℃, the conversion rate increases with the increase of polymerization temperature, up to 90% at 50 ℃; above 50 ℃, the conversion rate decreases. Compared to the general molybdenum system, the sequence length of the 1,2-linked isomeric stereoisomers in the resulting polymer has increased to about 4.2.