以亚磷酸二烷基酯为第三组分的铁系催化体系催化1,3-戊二烯聚合

摘要

以亚磷酸二烷基酯(简称P)为第三组分的铁系催化剂催化1,3-戊二烯(PD)聚合,考察了P的种类及用量、铝助催化剂(简称Al)的种类及用量对聚合的影响.结果表明,P和Al的结构对PD聚合活性影响较大,聚合活性随着P中烷基基团的增大而降低;Al对PD聚合活性的影响由强到弱为:三异丁基铝[Al(i-Bu)3]、三乙基铝、甲基铝氧烷.以2-乙基己酸铁(简称Fe)/Al(i-Bu)3/亚磷酸二乙酯(DEP)为催化剂,Al(i-Bu)3/Fe(摩尔比)为10和DEP/Fe(摩尔比)为2时,在50℃下具有高的PD聚合活性,所得聚合物数均分子量高,相对分子质量分布窄,1,2-结构含量高.%The polymerization of 1,3-pentadiene (PD) catalyzed by iron-based catalysts with dialkyl phosphite (simplified as P) as the third component,and the effects of types and amount of P and aluminium co-catalyst (simplified as Al) on the polymerization were examined.The results showed that the microstructure of P and Al had great influence on the polymerization activity of PD,and the polymerization activity decreased with the increase of the size of alkyl group in the P.The sequence of the effect of Al on polymerization activity of PD from strong to weak was triisobutylaluminium [Al (i-Bu) 3],triethylaluminum and methylaluminoxane.When 2-ethylhexanoic acid iron (simplified as Fe)/Al (i-Bu) 3/diethyl phosphite(DEP) was used as catalyst,Al(i-Bu) 3/Fe (mole ratio) was 10,DEP/Fe (mole ratio) was 2,the polymerization activity of PD was high,and acquired polymer had a higher number average molecular weight,narrower molecular weight distribution and higher 1,2-structure contents at50 ℃.