Patent ID: 8664352

Claim:
A method of making a polyester polyol from a natural oil-based starting composition, the method comprising the steps of: (a) providing a starting composition comprising up to about 95% weight monounsaturated fatty acids/alkyl esters derived from natural oils; (b) epoxidizing at least a portion of carbon-carbon double bonds in the starting composition to form an epoxidized fatty acid/alkyl ester composition; (c) drying the epoxidized fatty acid/alkyl ester composition to provide a dried epoxidized fatty acid/alkyl ester composition; (d) reacting the dried epoxidized fatty acid/alkyl ester composition with an alcohol or hydrogen to ring-open at least a portion of the epoxide groups to form a composition comprising hydroxylated fatty acids/alkyl esters, wherein the hydroxylated fatty acids/alkyl esters comprise a secondary alcohol; and (e) reacting the hydroxylated fatty acid/alkyl ester composition with a multifunctional ester-reactive initiator compound according to the formula A Q-H] p+q where: A is an organic group; with the proviso that A does not contain an ester of a monofunctional alcohol; (p+q) is an integer greater than or equal to 2; and -Q-H are independently ester-reactive functional groups, such as alcohols (i.e., -Q- is —O—) and amines (i.e., -Q- is to form the polyester polyol.