Development of multifunctional polyurethane elastomer composites containing fullerene: Mechanical, damping, thermal, and flammability behaviors

Thermoplastic polyurethane (TPU) composites filled with fullerene in the range from 0.5 wt% to 2 wt% were fabricated using melt-compounding. Fullerene addition levels up to nearly twofold increase in tensile strength, percent elongation, and modulus of TPU. The mechanical properties are improved as modified C60 content decreases. Fullerene loadings also enhance thermal stability of TPU. Glass transition temperature decreases by the inclusion of C60 into TPU matrix. Composites exhibited the improvement for storage modulus and vibration-damping behavior. The UL-94 rating and limiting oxygen index value of TPU are also extended to higher values after C60 loadings. Adjuvant effect is observed on fire performance in which pristine C60 inclusions and higher concentrations of C60 exhibit better fire performance. Additions of C60 give identical melt flow index values with that of TPU. Modified C60 particles disperse more homogeneously than pristine ones into TPU matrix because of the improvement in interfacial interactions between fullerene and polyurethane elastomer