URETHANE PLASTICS BASED ON STARCH AND STARCH-DERIVED GLYCOSIDES

Urethane plastics were prepared from a polymeric diisocyanate and a series of mixed polyols—castor oil and the products from alcoholysis of castor oil with glycol glycosides. In formulating the plastics, the equivalent ratio of isocyanate to polyol (NCO/OH) was varied from 1 to 2 and the polyol equivalent weight from 200 to 336. Starch was incorporated into these formulations to determine its effect upon the chemical cost and properties of urethane plastics. The plastics were prepared by uniformly mixing the components and subjecting the mixture to pressure molding at 140°C. As the amount of starch was increased from 0 to 60%, the NCO/OH ratio from 1 to 2, and the polyol equivalent weight was decreased from 336 to 200, there was a corresponding increase in tensile strength, hardness, and heat resistance of the plastics. The use of starch and starch-derived glycol glycosides can significantly reduce chemical costs of urethane plastics. © 1969, American Chemical Society. All rights reserved.