Electroactive shape memory performance of polyurethane/graphene nanocomposites

A series of electroactive shape memory polyurethane (SMPU) nanocomposites were synthesized from poly(tetramethylene ether) glycol (PTMG), 4,4-methylenebis(phenyl isocyanate) (MDI) and 1,3-butandiol (1,3-BD) with the addition of various amounts of thermally reduced graphenes (TRG) which were chemically modified with allyl isocyanate (iTRG). The effects of iTRG on electroactive shape recovery behaviors as well as the conventional direct heat actuated SMPU material have been studied in terms of morphological, thermal, mechanical, electrical properties and thermomechanical cyclic behavior. It was found that significant increases in electrical conductivity and temperature were obtained high iTRG contents (>2%) to electrically actuate the nanocomposite, along with large increases in glass transition temperature (Tg) and initial modulus with a dramatic drop in elongation at break.