双核苯氧亚胺类催化剂的制备及烯烃聚合

Synthesis of Binuclear Complexes Containing Phenoxyimine Ligands and Application for Ethylene Polymerization and Copolymerization

合成了5个不同结构的苯氧亚胺配体L1～L5,用Et_3N,Me_3SiCl或HNa处理后与TiCl_4·2THF或CpZrCl_3·DME进行配位反应得到不同取代基结构的化合物C1～C6,经过~1H NMR,^(13)C NMR,IR和元素分析等表征,确认了化学结构.以甲基铝氧烷(MAO)为助催化剂,化合物C1～C6为催化剂催化乙烯聚合,考察了聚合温度、乙烯压力、铝钛或铝锆比对催化剂活性及聚合物分子量的影响.聚合实验结果表明,刚性桥基结构提高了双核化合物(LMCl_3)_2的稳定性,催化剂的活性基本都能达到10~5～10~~6g/(mol M·h),其中C5的催化活性最高,达到1. 23×10~6g/(mol Zr·h); C4在Al/Ti摩尔比为50∶1时也具有较好的催化活性[5. 89×10~5g/(mol Ti·h)],聚合物分子量1. 11×10~6.该类催化剂还可以有效催化乙烯与1-辛烯共聚,1-辛烯插入率达到10. 65%(摩尔分数).

Binuclear complexes with phenoxyimine ligand were designed and synthesized,in which the ligands were synthesized by a condensation reaction of p?phenylenediamine and substituted salicylaldehyde.Binuclear complexes C1-C6 were synthesized by the TiCl4·2THF or CpZrCl3·DME reacted with the ligands treated with triethylamine,trimethylchlorosilane or sodium hydride.Both the ligands and the compounds were well characterized by 1H NMR,13C NMR,IR,element analysis and MS.When combined with methylaluminoxane(MAO),the binuclear complexes show higher activity for ethylene polymerization.The effects of polymerization factors such as temperature,pressure of ethylene,ratio of aluminum to titanium or zirconium on the catalytic activity and polymer molecular weight were also investigated.The experimental results show that the activity of the catalysts reached 105-106 g/(mol M·h);and the catalyst C5 has the highest catalytic activity of 1.23×10^6 g/(mol Zr·h).However,the C4 could keep higher catalytic activity when the molar ratio of Al/Ti was lower to 50∶1,and the molecular weight of the polymer was higher to 1.11×10^6.It is also found that the catalyst could effectively catalyze the copolymerization of ethylene with 1-octene and the insertion rate of 1-octene could reach to 10.65%(molar fraction).