Epoxy-Amine Polymerization to Access Poly(β-hydroxyl amine)s with Active Tertiary Amino Pendant Groups

Epoxy-amine polymerization was investigated as a synthetic method for developing poly(β-hydroxyl amine)s with active tertiary amino pendant groups. Primary amines bearing pyridinyl, imidazolyl, dimethylamino, diethylamino, and dibutylamino groups, along with controls bearing mild groups, were used in the polymerization with diglycidyl ether of bisphenol A. While optimized solution polymerization was established by using the primary amines substituted with mild groups, only dibutylamino groups were incorporated as active tertiary amino pendant groups into thermoplastic polymer without gelation. In bulk polymerization, the presence of all additional tertiary amino groups led to cross-linking. Model reactions showed two pathways where the tertiary amino groups involve cross-linking, which varied depending on the nucleophilicity and steric effects of the tertiary amino groups. The choice of tertiary amino group and stoichiometric imbalance between epoxy and amino monomers affected the physical properties of the resulting thermosetting polymers, which possess partially quaternized backbones with β-hydroxyl and active tertiary amino pendant groups.