| abstract |
Polycarboxy-oxyalkylene polyester-ether polyol intermediates useful in the production of polyurethane products and methods of making the intermediates and polyurethane products are described. The polyol intermediates are made from lignin by reacting lignin with maleic anhydride, substituted maleic anhydride, or mixtures thereof to form carboxylated lignin maleic anhydride copolymers. These copolymers are then reacted with an oxyalkylating medium with or without prior hydrolysis to form the polyol intermediates. These polyester-ether polyol intermediates are then reacted with an isocyanate medium having an isocyanate with at least 2 NC0 groups per molecule to produce polyurethane products with or without simultaneous foaming. |