Urethane foams from animal fats: VIII. Properties of foams from epoxidized tallow trimethylolpropane polyols

Abstract

Polyols made by reacting trimethylolpropane with epoxidized tallow were converted to urethane foams by reaction with a polymethylene polyphenylisocyanate in the presence of fluorotrichloromethane. Adjusted with triisopropanolamine or an oxypropylated triamine to hydroxyl equivalent of either 100 or 120, the polyols yielded rigid foams of density 1.5–2.0 lb/ft³, open cell content 15–19%, and compressive strength 34–49 psi. These values were superior to those of similar foams from hydrated epoxidized tallow. Polyols made from epoxidized tallow-trimethylolpropane-HBr and adjusted to equivalent wt of 100 and 120 by triisopropanolamine gave foams whose small-scale flammability test samples burned less than 20% of their length. At hydroxyl equivalent 100, foams had density 1.6–1.8, open cell content 20–21%, and compressive strength 34–39 psi; in flammability tests burned <20% of length. The present foams were stronger than those made earlier from solvent-purified hydroxybrominated tallow. Formulation with half the normal amount of freon gave foams of higher compressive strength but lower flame resistance.