(P^N^P)钴配合物/倍半氯化乙基铝催化苯乙烯聚合的研究

Polymerization of Styrene Catalyzed by(P^N^P) Cobalt(Ⅱ) Complexes /Ethylaluminum Sesquichloride

采用含氮双膦配体与无水氯化钴反应可制得一系列相应的（P^N^P）钴配合物,并研究了该系列钴配合物对苯乙烯聚合的催化性能.在助催化剂倍半氯化乙基铝（EASC）的活化下,该系列钴配合物对甲苯中的苯乙烯溶液聚合表现出高的催化活性（可达5.44×105g（PS）·mol-1（Co）·h-1）.通过对不同苯乙烯单体用量、助催化剂用量（Al/Co摩尔比）、聚合温度以及催化剂的配体环境等的研究,详细考察了这些因素对聚合反应和聚合产物性能的影响.通过凝胶渗透色谱法（GPC）和核磁共振碳谱（13C-NMR）表征了所得聚合产物的分子量及分子量分布和微观结构,分析结果表明,所得聚苯乙烯具有较低的分子量（Mn=2000~5900）和较窄的分子量分布（1.75~2.05）,其微观结构是无规的.

A series of（ P ^ N ^ P） cobalt（ Ⅱ） complexes were prepared by the reaction of N-containing diphosphine ligands and anhydrous cobalt dichloride and their catalytic performance in the polymerization of styrene were also investigated. Upon activation with ethylaluminum sesquichloride（ EASC）,all these cobalt complexes showed high catalytic activities up to 5. 44 × 105g（ PS）·mol- 1（Co）·h- 1for the solution polymerization of styrene in toluene. The reaction parameters,such as styrene concentration（2 ~ 4 mL）,Al /Co molar ratio（20 ~ 160）,reaction temperature（0 ~ 70 ℃） and ligand structure of cobalt complexes were employed in order to study their influences on the polymerization of styrene and the properties of the resulting polymers. The molecular weight,molecular weight distribution and microstructure of the resulting polymers were characterized by GPC and13C-NMR spectra. The GPC results indicated that all the polystyrenes obtained had low molecular weight（Mn= 2000 ~ 5900） and narrow molecular weight distribution（1. 75 ~ 2. 05）. The13 CNMR spectra demonstrated that the microstructure of polystyrenes obtained was atactic.