Controlled Polymerization in Polar Solvents to Ultrahigh Molecular Weight Polyethylene

摘要

Novel complexes based on 2,4,8-triarylnaphthylamine [[(2,4-{3,5-(CF_(3))_(2)C_(6)H_(3)}_(2)-8-(3,5-R_(2)C_(6)H_(3))-C_(10)H_(4))—N═C(H)—{3-(9-anthryl)-2-O-C_(6)H_(3)}-κ~(2)-N,O]Ni(CH_(3))(pyridine)] (4-Py , R = Me; 5-Py , R = CF_(3)) were synthesized from 8-arylnaphthylamines which can be generated via selective lithiation, borylation, and coupling in a one-pot procedure. Due to their living characteristics in ethylene polymerization and the particularly low propensity of 5-Py for β-H elimination as reflected by a high linearity even at elevated polymerization temperatures of 60 °C, ultrahigh molecular weight polyethylene (UHMWPE) is formed in polar organic solvents (THF, diethyl ether) as a reaction medium in a controlled polymerization (M _(w)/M _(n) = 1.2 at M _(n) = 1.1 × 10~(6) g mol~(–1)).