Thermal characterization of carboxylic functionalized graphene reinforced polyurethane nanocomposite

Abstract

Nanocomposites of Polyurethane reinforced with Carboxylic functionalized Graphene are prepared from solvent mixing technique for different weight composition of 0%, 1%, 5% and 10% of the filler and thermal properties are examined in this paper. Magnetic stirring is performed to disperse the sonicated Graphene in DMF solution in the PU/DMF Solution. FESEM is performed to characterize the sample morphology. Thermogravimetric analysis is performed on the thin films to determine the degradation of nanocomposite with increasing temperatures. It is observed that the thermal stability improves with addition of nano filler to the polymer. The Thermogravimetric analysis results show that an improvement of degradation temperature at 2%, 10% and 50% mass loss are improved by 12 °C, 2 °C, 0.5 °C; 14 °C, 7 °C, 2 °C; 19 °C, 8 °C and 6 °C respectively for 1 wt%, 5 wt% and 10 wt% of Graphene in PU. Maximum weight loss for the samples occurred between 350 °C and 400 °C. Carboxylic group functionalization of Graphene lead to strong interfacial interactions between the nanofiller and Polyurethane matrix. Proper dispersion of Graphene in the nanocomposite and char formation due to delayed escape of volatile degradation products caused due to the tortuous path effect of Graphene nano sheets lead to thermal stability of the nanocomposite.