Urethane foams from animal fats: V. Flame resistant foams from hypohalogenated glycerides

Abstract

A series of urethane foams has been prepared using hypohalogenated derivatives of triolein, monoolein, lard and tallow as the polyol ingredient. Two-step hypohalogenation was achieved by epoxidation of the glyceride, followed by treatment with HX. One step hypohalogenation was effected by direct addition of hypochlorous acid (from calcium hypochlorite) or hypobromous acid (from N-bromoacetamide). The polyols, which varied from viscous liquids to semi-solids, were adjusted in equivalent weight with triisopropanolamine. Urethane foams were prepared from the adjusted polyols using polymeric polyisocyanate as the isocyanate, triethylene diamine catalyst and Freon 11 as blowing agent. Additional foams were made with 2% antimony oxide as an added fire retardant. Rigid foams were obtained from each glyceride polyol. Fire retardant properties were measured using a modification of ASTM Method D1692-59T. In each case, the foams exhibited greater flammability resistance than those obtained from polyols containing no halogen atoms. It was noted that the presence of antimony oxide was necessary in order to attain nonburning foams but was accompanied by a lowering of compressive strength.