Aromatic polyester polyols from dimethyl terephthalate process residue and tall oil fatty acids

Abstract From the Canadian patent

A polyester polyol composition is prepared by (1) reacting 5 to 40 percent tall oil fatty acids, (b) 20 to 80 percent dimethyl terephthalate process residue and (c) 20 to 60 percent polyhydric alcohol, based on the weight of the reaction mixture in the presence, of an esterification/transesterification catalyst while continuously removing water and methanol that are formed during the reaction to, form a first reaction product containing residual carboxylic acid functionality and (2) reacting 1 to 25 percent of at least one alkylene carbonate, or an equimolar amount of at least one alkylene oxide, with the residual carboxylic acid functionality in the presence of a catalyst. The preferred …