CHARACTERIZATION OF CURE PROFILE OF ANAEROBIC ADHESIVES BY REAL-TIME FT-IR SPECTROSCOPY .1. EFFECT OF TRANSITION-METAL DITHIOLATE COMPLEXES

A model acrylic adhesive formulation consisting of triethylene glycol dimethacrylate (TRIEGMA) monomer, cumene hydroperoxide (CHP), o-benzoi c sulfimide (saccharin or BS) and with or without a metal dithiolate c atalyst has been made to study kinetics and mechanism of the anaerobic polymerization. In these studies, a real-time FT-IR spectroscopic (RT /FF-IR) technique has been used to study anaerobic cure profiles at ro om temperature. The catalytic effect of several transition metal dithi o complexes for redox-initiated acrylate polymerization has been studi ed. The dithiolates used in these studies include the dithiocarbamate, xanthate dithiophosphate complexes of copper, nickel and zinc systems . Copper diacetylacetonate was also studied for comparison of its cata lytic reactivity. A synergistic effect of copper dithiolate catalyst a nd saccharin was observed. The effects of catalyst concentration, meta l and ligand type, and co-initiator on cure profiles have been monitor ed in a real-time mode.