High elongation thermoplastic Polyester‐urethanes based on widely available diacid intermediates

A series of new α,ω‐dihydroxy terminated polyester oligomers are synthesized from the condensation reaction of various aliphatic diols with a mixture of diacids rich in 2‐methylglutaric acid, MGA, an abundant and well‐defined industrial product. Their adipic acid (AA)‐based counterparts are also prepared and the physico‐chemical properties of both types of polyols are thoroughly characterized. All these polyester polyols are then used to prepare segmented polyurethanes following a two‐stage process, by reacting them successively with 4,4′‐diphenylmethane diisocyanate, and 1,4‐butanediol. The resulting materials are then evaluated with respect to their thermal and dynamic or static mechanical properties. The observed characteristics and behaviors are quite similar between AA‐ or MGA‐based polyurethanes, except for the tendency of AA‐based samples to display partially crystallized soft domains. Such a phenomenon is prevented in MGA‐based samples because of the methyl side group, resulting in remarkably higher ultimate elongations for the new thermoplastic polyurethanes derived from MGA. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43410.