论文部分内容阅读
1.比较了几种希土元素和不同配位体对丁戊共聚的催化活性,以及所得共聚物的组成和结构。从催化活性与工业化角度来看,认为采用镨钕富集物的去铈混合希土环烷酸盐比较合适。2.测定了丁二烯与异戊二烯在四种希土催化体系中共聚的表观活化能和竟聚率。r_1与 r_2均大于1,表明是嵌段共聚物,并对共聚物的序列分布作了讨论。3.共聚物的组成与微观结构不受聚合温度(20—50℃),聚合时间(5—60分)和溶剂性质(芳烃或脂肪烃)的影响。4.在共聚物中丁二烯链节的顺-1,4含量和异戊二烯链节的1,4总含量都在96%(克分子)以上。并且不论共聚物的组成怎样变化,1,4链节的含量变化很小。 5.考察了影响共聚物[η]的一些因素,其中烷基铝的纯度、溶剂的性质以及添加剂的影响较大。
1. The catalytic activities of several rare earth elements and different ligands on the copolymerization of butylene oxide were compared, and the composition and structure of the copolymer obtained were compared. From the perspective of catalytic activity and industrialization, it is believed that the cerium mixed naphthenic naphthenate using praseodymium neodymium enrichment is more suitable. The apparent activation energy and aggregation rate of butadiene copolymerization with isoprene in four kinds of rare-earth catalysis were determined. Both r_1 and r_2 are greater than 1, indicating a block copolymer, and the sequence distribution of the copolymer is discussed. 3. The composition and microstructure of the copolymer are not affected by the polymerization temperature (20-50 ° C), the polymerization time (5-60 minutes) and the nature of the solvent (aromatic or aliphatic). 4. The cis-1,4 content of butadiene linkages and the 1,4-content of isoprene linkages in the copolymer are both above 96% (moles). And no matter how the composition of the copolymer changes, 1,4 chain changes little. 5. Some factors affecting the [η] of the copolymer were investigated, in which the purity of the aluminum alkyl, the nature of the solvent and the influence of the additives were great.