采用市售的BF3醚类和BF3醇类液体络合物直接进行异丁烯聚合的小试研究.以这两类BF3络合物为催化剂,研究了络合物加入量、聚合温度、聚合时间及溶剂极性等对异丁烯聚合的影响.结果表明:当以正己烷为溶剂时,两种络合物均能有效合成相对分子质量在500-5000,α-双键含量在80%以上的高活性低相对分子质量聚异丁烯,但BF3醇络合物比BF3醚络合物具有更高的催化活性.其中,BF3乙醇络合物的活性最高,而采用BF3醚络合物为催化剂得到的聚异丁烯则具有更窄的相对分子质量分布.此外,降低聚合温度或BF3浓度可提高聚异丁烯的相对分子质量.
The synthesis of highly reactive low molecular weight poly-isobutylene(HR-PIB)is catalyzed in laboratory by BF3-alcohol/ether liquid complexes, which can be easily purchased from the market. The impacts of polymerization conditions on the reaction such as complex concentration, temperature, polymerization time, and solvent polarity are investigated with these BF3 catalysts respectively. The results show that both catalysts are able to initiate isobutylene polymerization in hexane solvent to prepare HR-PIB in a low molecular mass of 500-5 000 and the α-double bond content above 80%. The BF3-alcohol complexes, however, show much higher catalytic activity than BF3-ether complexes, among which, the BF3-ethanol complex represents the highest activity. The polymer synthesized by BF3-ether complexes, on the other hand, has much narrower relative molecular mass distribution than that obtained from BF3-alcohol complexes. Moreover, the relative molecular mass of the HR-PIB could be increased by lowering the polymerization temperature or concentration of the BF3 complexes.