Effect of multi-walled carbon nanotubes on thermal stability of polyurethane nanocomposites

This paper examines the thermal expansion of polyurethane (Pu)/multi-walled carbon nanotube (mwcnt) composites over a temperature range of 45 °C to 70 °C. Composites of PU, with varying MWCNT compositions, have been fabricated by solution mixing. They were moulded in the form of discs with a diameter of 10 mm and thickness of 5 mm. By using a thermal dilatometer, a reduction of 58.31% in the coefficient of thermal expansion (CTE) of the 5 wt% composite was observed, with respect to pure PU. Thermo-gravimetric analysis (TGA) studies revealed a 15% weight loss and the thermal decomposition temperature of PU/MWCNT composite with 1 wt% was improved by 12 °C, with respect to pure PU. We suggest the uniform dispersion of MWCNT as an explanation for reduced strain, which leads to reduced CTE of PU-based MWCNT composite materials.