In an active hydrogen-containing B-side composition for reaction with a polyisocyanate-containing A-side composition to make a polyurethane, polyurethane/urea or polyurea elastomer by reaction injected molding, the improvement which comprises a crosslinking polyol composition which is the reaction product of a C.sub.12 -C.sub.36 fatty acid with a polyalkylene polyamine to yield an intermediate imidazoline-containing polyamine reaction product having at least one C.sub.11 -C.sub.35 alkyl substituent and further reacting the intermediate reaction product with a C.sub.2 -C.sub.21 reactive epoxide.