负载苊二亚胺镍/烷基铝催化单一乙烯制备高支化聚乙烯

Single Ethylene Polymerization Catalyzed by Supported Acenaphthenequinonediimine Nickel(Ⅱ) Complexes/AlEt_2 Cl

1995年,Brookhart 等人以大体积α-二亚胺为配体制备了Ni（Ⅱ）和Pd（Ⅱ）的配合物,作为乙烯聚合催化剂,能有效的抑制反应过程中的β-H消除反应,从而实现了促进链增长的目的,得到了高分子量的聚合物.这类催化体系一般是以二亚胺镍的溴化物为主催化剂,MAO作助催化剂,均相催化乙烯聚合.

[ （N-1 -naphthylimino-N＇ -2, 6-isopropylphenylimino） acenaphthene] dichloronickel （ Ⅱ ） was prepared and supported on SiO2/MgCl2 to afford a supported catalyst. With general alkylaluminium as cocatalyst, this supported catalyst was used for ethylene polymerization to produce branched polyethylene. The results show that the polymerization conditions have pronounced influence on catalytic activity and properties of polymerization. When AlEt2 C; was used as cocatalyst, the catalyst is high active for ethylene polymerization, producing branching polyethylenes with 31.2 -62.5 branehers per 1000 carbon atoms. Branching degree of polyethylene increase correspondingly. When the polymerization temperature was 25 ℃ and AI/Ni molar ratio 80 , the supported catalyst achieved highest activity of 5.2 × 10^5 g PE（ molNi · h）^ -1.