A combined experimental and computational study on the material properties of shape memory polyurethane
A type of shape memory polyurethane with 60 wt% hard segments (SMPU60) was prepared. Its material properties were tested by dynamic mechanical analysis (DMA) and Instron, and simulated using fully atomistic molecular dynamics (MD). The glass transition temperature (T-g) of SMPU60 determined by DMA is 316 K, which is slightly lower than that estimated through MD simulations (T-g = 328 K), showing the calculated Tg is in good agreement with experimental data. A complex hydrogen bonding network was revealed with the calculation of radial distribution functions (RDFs). The C=O center dot center dot center dot H bond is the predominant hydrogen-bonding interaction. With increasing temperature, both the hydrogen bonding and the moduli decreased, and the dissociation of intermolecular hydrogen bonding induced the decrease of the moduli.
material property polyurethane dynamic mechanical analysis fully atomistic molecular dynamics