Flexible and compatible polymer composite blends based on polyurethane/sodium ionomer/lignin and their properties

Polyurethane, sodium ionomer (Surlyn 8150), and lignin (PSL)-based composite films were prepared by the solution casting method with different weight percentages of lignin. The relationships among the morphology, thermal resistance, mechanical, and dynamic mechanical properties for all composites were characterized. The structural interactions, microstructure, and optical properties of the composite were studied by Fourier transform infrared, scanning electron microscopy (SEM), X-ray diffraction, and ultraviolet (UV) spectroscopy. The mechanical and UV absorbance properties of the composite films improved significantly with the addition of lignin particles. The tensile strength increased from 42.5 to 57.2 MPa. Dynamic mechanical analysis results show that the storage modulus of the composites increased and exhibited a single T-g. PSL composite films show excellent water barrier properties, with improved surface hydrophobicity. SEM images revealed that a relatively uniform phase morphology and good interfacial compatibilization wereachieved. These results suggest that all of the composite films with PU, Na ionomers, and lignin materials exhibited good compatibility and miscibility. (c) 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48885.