Thermosetting resins from vegetable oils

A range of polyols and thermosetting polyurethanes was prepared from soybean, corn, sunflower, safflower, canola, peanut, olive and castor oils. The products were rigid plastics if the polyol hydroxyl number was 160 mgKOH/g or above, or rubbers when the OH number was below that value. T-g of the resins showed linear dependence with the hydroxyl number. The exception was castor oil, which was rubbery, although the OH number was 164 mgKOH/g, which was attributed to the presence of double bonds.