Enhanced polyurethanes based on different polycarbonatediols

Abstract

Segmented thermoplastic polyurethanes (PUs) were prepared from 4,4′-diphenylmethane diisocyanate (MDI), 1,4-butanediol (BD) and different macrodiols with a molar mass of 1000. Properties of those PUs based on polycarbonatediol (PCD) were compared with their homologous based on polyesterdiol and polyetherdiol as macrodiols. The proportion used in this study was macrodiol:BD:MDI = 1:2:3, in mole ratio. The hard segment weight percentage is 48 wt% for different PUs. Thermogravimetric analysis, differential scanning calorimetry, differential mechanical analysis, Fourier transform infrared-attenuated total reflection spectroscopy, as well as mechanical properties and retention on flexural properties tests were employed to characterize the physicochemical, thermal and mechanical properties of different PUs. Comparison of PUs based on PCD, ester and ether macrodiols indicates a better miscibility, higher hard segment–soft segment interactions and durability for the ones based on PCD. It is especially noticeable that the transparency of the films obtained with PCD as macrodiols as well as their good tensile strength and performance to standard durability tests, in comparison with those based on polyester and polyether. This trend could be related with a better miscibility caused by the highest hard segment–soft segment interactions favored by the presence of the carbonate groups.