Shape memory polyurethanes based on polyols derived from renewable resources

Segmented polyurethanes have been synthesized employing polyols derived from renewable resources, semicrystalline or amorphous in nature, as soft segment, and an aliphatic (1,6-hexamethylene diisocyanate, HDI) or aromatic (4,40- diphenylmethane diisocyanate, MDI) diisocyanate and 1,4-butanediol (BD) as hard segment using two-step bulk polymerization procedure. The effect of soft and hard segment structure and hard segment content on thermal, mechanical and shape memory properties has been studied by means of differential scanning calorimetry, tensile tests and tensile tests performed using a thermal chamber.