Synthesis of phosphorylated esters and oligoesters, prepared from unsaturated acids and glycols, and their use as flame retardants for rigid polyurethane foams

Abstract

Unsaturated esters and oligoesters of itaconic and methacrylic acid have been synthesized through transesterification of dimethyl itaconate and methyl methacrylate with ethylene glycol and diethylene glycol. Dialkyl phosphites and bis(ω-hydroxyethoxyethyl)phosphite have been added to the double bonds of the products by the Pudovik reaction. Some of the phosphorylated products have been employed as viscosity reducing additives to polyesteralcohols, which were used in the synthesis of rigid polyurethane foams. The presence of phosphorus in the additives accounts for the observed increase in the fire resistance of the prepared polymers.