Abstract: A polyurethane or polyurethane-urea elastomeric composition, characterized in that the composition is a reaction product of:(A) a soft segment macrodiol which is either:(i) a homopolymer represented by formula I,HO--[(CH.sub.2).sub.n O].sub.m --H Iwherein n represents an integer greater than 5 and less than 13, m is a number such that the number average molecular weight of the compound of formula I falls in the range from 218 to 5000 and optionally at least one hydrogen atom represented in formula I is substituted by a C.sub.1 to C.sub.3 alkyl group or a halogen atom;(ii) a copolymer containing at least 25% by mass of repeating units --(CH.sub.2).sub.n O-- wherein n is as defined in formula I above; or(iii) mixture of macrodiols comprising greater than 10% of a macrodiol as defined in formula I above;(B ) an aliphatic or aromatic diisocyanate known in the art of polyurethane manufacture; and(C) optionally a chain extender.