Biobased Aromatic-Aliphatic Polyols by Thiol-Ene Reactions of Propoxylated Mercaptanized Cardanol

Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans; these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties. The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps. The first step is propoxylation of cardanol by reacting cardanol with propylene oxide; the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide; and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol, glycerol-1-allyl ether, and trimethylolpropane allyl ether. Thus, obtained polyols were characterized by standard analytical methods. Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties. The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers, storage tanks and pipes for food and chemical industries, wood substitutes and flotation materials.