Synthesis and characterization of hydroxyethyl cellulose copolymer modified polyurethane bionanocomposites

Bio based polyurethane nanocomposites (renewable thermosets) show a diverse range in properties, processing components and production of smart materials for health, food, and energy sectors. In this work, polyurethane nanocomposites based on isophorone diisocyanate (IPDI), and hydroxyl terminated-polybutadiene (HTPB) incorporating clay were modified using hydroxyethyl cellulose (HLAC) to be further assessed for thermal and mechanical properties. Elastomers samples were prepared by blending clay suspension and PU prepolymer to attain clay contents of 0.3, 0.5, and 1% (weight on dry basis) along with butane diol and HLAC chain extenders. Effect of nanofiller aggregation and dispersion on the thermal degradation and surface morphology of the bionanocomposites were studied. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy/energy dispersive X-ray (SEM/EDX) and thermal gravimetric (TG) techniques were used to investigate the interactions among PU matrix, clay nanofillers, and HLAC. Mechanical testing indicated an increase in tensile strength and a decrease in elongation at break (%) by just adding 0.3 wt% clay. The thermal stability of the bionanocomposites was improved with the addition of clay. The results of the thermal and mechanical studies demonstrated the feasibility of the bionanocomposites as strong and thermally stable elastomers with low filler loading.