Effects of CaCO₃ and AI(OH)₃ on Properties of Inverted Emulsions and Polymers from Vinyl Monomers with Acid Anhydride-Adducted Polypropylene Glycol

Abstract

Adduct polymer (PPGMA) prepared from polypropylene glycol and maleic anhydride was found to give stable inverted emulsions when a slurry of CaCO₃-water was added with stirring into vinyl monomers in the presence of PPGMA. At least part of the carboxyl groups of PPGMA are considered to be neutralized with Ca²⁺ generated from CaCO₃ into partially neutralized PPGMA which acts as an effective W/O-type emulsifier. The inverted emulsions containing CaCO₃ as filler showed very low viscosities and, on polymerization, gave water-containing polymers which are characterized by a high rate of water loss. The water-free polymers obtained by removing water showed physical properties which generally decrease with an increase in the PPGMA amount, due to a change in cell structure and also to an increase in the plasticizing effect of PPGMA. The use of mixed fillers of CaCO₃ and A1(OH)₃ was found to impart flame-retardant properties to the polymers without significant changes in the physical properties.