摘要
研究了在不用甲基铝氧烷.只以通用烷基铝为助催化剂的条件下,以SiO2和MgCl2的复合载体负载3种镍二亚胺配合物催化乙烯进行聚合,庚烷为溶剂制备支化聚乙烯(PE)。结果发现,聚合条件(如配体、载体改性方式、助催化剂、铝/镍、聚合温度和金属镍浓度等)对催化活性有很大的影响。没有经三乙基铝改性的复合载体负载空间位阻最小的镍二亚胺配合物在以-氯二乙基铝为助催化剂、聚合温度14℃、金属镍浓度0.12 mmol/L、铝/镍为80的条件下催化活性达290 kg/mol·h),生成的支化PE的支化度随着聚合温度的升高而迅速增加。
Ethylene polymerization catalyzed by three nickel diimine complexes supported on Si02/MgCl2 composite with trialkylaluminium (AlR3) as co-catalyst was performed in the absence of methylaluminoxane (MAO), and branched polyethylene (PE) was prepared with n-heptane as solvent. Reaction conditions had significant effects on catalytic activity, such as ligand, modification method of support, co-catalyst, molar ratio of Al : Ni, polymerization temperature and concentration of nickel metal. Under the conditions of using aluminium diethyl monochloride as co-catalyst, polymerization temperature 14 ℃, metal nickel concentration 0.12 mmol/ L, molar ratios of Al : Ni 80, the catalytic activity of nickel diimine complex reached as 290 kg/(mol · h). The catalyst had minimum steric hindrance and was supported on the composite carrier that was not subject to the treatment of AlR3. The branching degree of the resultant branched PE increased rapidly as the polymerization temperature went up, however, it was influenced a little by molar ratio of Al : Ni.
出处
《合成树脂及塑料》
CAS
2004年第1期6-9,共4页
China Synthetic Resin and Plastics
基金
广东省自然科学基金(031598)
