Polymerization of epoxides in the presence of tertiary amino alcohols

Polymerizations of phenyl glycidyl ether (PGE) and the diglycidyl ether of Bisphenol A (DGEBA) were initiated with tertiary amino alcohols. The reaction was followed by means of HPLC and IR spectroscopy. The main products isolated from the reaction mixture were identified by using mass spectrometry. The sol fraction and the critical conversion at the gel point were determined for the crosslinking polymerization of DGEBA. Three series of oligomers arise from three initiating centers during the polymerization of PGE. In addition to the amino alcohol—a product of the secondary amine addition to the epoxy group—the phenol arising in the reaction mixture also acts as an initiator. The third oligomer series propagates by an anionic mechanism from a quaternary ammonium base originating from the reaction of PGE with the amino alcohol. Formation of the new initiating centers during the reaction results in a decrease in the molecular weight of the polymer relative to the value predicted from the amount of initiator initially added. The relative content of products of the particular oligomeric series in the reaction mixture depends on temperature and on the concentration of the initiator.