Abstract: Polyester polyols are prepared by reacting a multifunctional adduct (e.g., maleic anhydride (MA)) and tall oil fatty acid, (TOFA), and then esterifying/transesterifying the MA/TOFA reaction product with an excess of aromatic polyester polyols (preferably such polyols are produced from dimethyl terephthalate (DMT) process residue and polyhydric alcohols). The polyester polyols may be used in the manufacture of rigid polyurethane (PUR) and rigid urethane-modified polyisocyanurate (PUR/PIR) foams.

Abstract: 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 alkylene carbonate/oxide is ethylene or propylene (or a mixture thereof) carbonate/oxide. A foamed laminate made from the polyester polyol has reduced surface friability and faster rates of cure.