This invention employs a polyol derivative of a fatty acid that is reacted into a polyurethane formed also with a urethane prepolymer, a polydiene, and optionally, a curative for cross-linking. The fatty acid moiety becomes a relatively short side chain of the polyurethane formed. In embodiments, the polyol is an ester of the fatty acid. This achieves reduction in hardness of the polyurethane with a homogeneity that provides consistent surface characteristics over an extended period desirable for use for electrophotographic development and the like when the material is used as a developer roller.