Urethane foams from animal fats. III. Oxypropylated dihydroxystearic acids in rigid foams

Abstract

Liquid polyols consisting ofthreo-orerythro-9,10-dihydroxystearic acid previously reacted with 1, 2, 4, 6 and 8 moles of propylene oxide were adjusted with triisopropanolamine to equivalent weight 100. Using trichlorofluoromethane as blowing agent and triethylenediamine as catalyst, the adjusted polyols were foamed by reaction with a prepolymer made from oxypropylated sorbitol and tolylene diisocyanate.

The resulting rigid foams had densities between 1.6 and 2.0 lb/ft³, the densities for thethreo series being parallel to but higher at each stage of oxypropylation than those of theerythro series. Compressive strengths in theerythro series ranged from 19 psi for the monooxypropylated compound to 38 psi for the octaoxypropylated member; in thethreo series from 27 to 39 psi. Properties improved in both series as the degree of polyol oxypropylation increased. This contrasted with foams prepared earlier from oxyethylated polyols, whose properties generally reached maxima at intermediate degrees of oxyethylation. Using the tetra-and hexaoxypropylatedthreo polyols, the proportion of blowing agent was varied to relate compressive strength to density of foams between 1.4 and 4 lb/ft³.