铁系亚胺基吡啶复配催化乙烯原位共聚产物的表征

Branched polyethylene from ethylene as single monomer was prepared by the tandem catalyst system of {2-[2-Me C6 H4 N=Me)]2 C5H3N} FeCl2 (1) and {2,6-[1-(2,6-Me2-4-Br-C6H4N=(Me)]2C5H3N} FeCl2 (2) activated with methylaluminoxane (MAO) . The products of polymerization were characterized by DSC, GPC and ^13C-NMR. The results revealed that the copolymer produced by in situ copolymerization of ethylene was a mixture of branched polyethylene and α-olefin. The content of α-olefin in the mixture was increased with increasing the molar ratio of catalysts 1/2. The MWD paramelers of polyethylene and copolymer were 28.6 and 7.9, respectively. ^13C-NMR spectra showed that there were ethyl groups, butyl groups and long chain alkyl groups in the copolymer. The average degree of branching of such branched polyethylene was less than 5C/1000C.