Poly(alkylene oxide) ionomers. VII. Use of triethylaluminum/water/acetylacetone (1.0:0.5:1.0) for the polymerization of oxiranes

Abstract

AbstractPolymerization studies of oxiranes were conducted using a modified aluminumalkyl initiator, derived from the low‐temperature reaction by chelating agents (5°C) and hydrolysis products of triethylaluminum. The stoichiometric reaction product of acetylacetone and triethylaluminum, after partial hydrolysis with water, gave a homogeneous initiator that polymerized the oxides of ethylene, propylene, 1‐butene, 1‐hexene, 3‐chloro‐1‐propene, and 4,4,4‐trichloro‐1‐butene to the corresponding high molecular weight poly(alkylene oxides). The initiator, similar in nominal composition to the classical trialkylaluminum/water/acetylacetone (1.0/0.5/1.0) initiator developed by Vandenberg, retained a high level of activity, when properly stored, for nearly 4 weeks. The composition was inactive when the sequence of chelation and hydrolysis was reversed. Inclusion of a proton‐trapping agent in polymerization experiments of propylene oxide provided evidence that protons do not play a role in the initiation of oxirane polymerizations with modified organoaluminum oxides. Characterization of the various alkylene oxide polymers was carried out by spectroscopic, solution, and thermal techniques.