A note on semirigid polyurethane forms based on castor oil

Abstract

Many of the modern commercial rigid and semirigid foams in the markets are more than a mere modification of the conventional polyester as originally used by Bayer. The modification in raw materials range from the introduction of blowing agentsto the use of fatty acidmodified polyols and to agreater extant even the wide use of polyethers as raw mateirals.