Synthesis and shape memory performance of polyurethane/graphene nanocomposites

Small amounts of allyl isocyanate modified graphene (iG, 0-2.5 phr) were incorporated into acrylate terminated polyurethane (PU) by UV curing. The effects of this incorporation on the morphological, mechanical, thermal and shape memory properties of the nanocomposites were examined. The iG nanoparticles incorporated into the PU chains acted as both multifunctional crosslinkers and reinforcing fillers, and the effects were most pronounced at 1.5 phr iG. Consequently, the glassy and rubbery state moduli, yield strength, glass transition temperature (Tg), shape fixity and shape recovery ratios were increased by adding up to 1.5 phr iG. Above the loadings, most of the above properties decreased due to aggregation and the auto-inhibition reaction of allyl compounds.