Development and Characterization of En-7: a Ferric Acetylacetonate Catalyzed Polybutadiene-Based Elastomer

Abstract

Improved cure efficiency of polybutadiene based-polyol cured elastomers was achieved by replacing the organomercury catalyst of the commercial formulation (EN-4) with small concentrations of ferric acetylacetonate [Fe(AcAc) 3 ]. Although the pot life of the Fe(AcAC) 3 catalyzed formulation, designated EN-7, was 20% shorter than that of EN-4, the pot life could be doubled by addition of minute quantities of acetylacetone without adversely affecting the improved cure efficiency. Spectroscopic analyses were carried out which corroborate that the Fe(AcAc) 3 catalysis of the isocyanate-alcohol reaction involves alcoholysis of the metal acetylacetonate. Characterization studies indicate that, if me chanical strength at elevated temperatures is not a requirement, EN-7 appears to be a viable replacement for Adiprene elastomers which are under suspension because of the alleged carcinogenic nature of the curing agent, MOCA.