Improvement in the Flame-Retardant and Mechanical Properties of Thermoplastic Polyurethane Nanocomposites

Abstract

Recently, nanocomposites of polymers gained much attention in materials as they frequently show advanced features as compared to their complement polymer micro-composites. In this study, Thermoplastic polyurethane (TPU) is used as matrix and Antimony trioxide (primary flame retardant) and Montmorillonite organo-clay (secondary flame retardant) along with Benzoflex (plasticizer) are used as fillers. Nanocomposites of varying composition (TPU-1 to TPU-6) are prepared via melt-mixing method. Samples are compressed to form sheets of desired dimensions through compression molding hydraulic press machine. Fourier transform infrared (FTIR) was applied for functional groups analysis. Scanning electron microscopy (SEM) was performed to examine the dispersion of fillers in the Nanocomposites. Differential scanning calorimetry (DCS) was also performed for evaluation of properties such as melting temperature and glass transition temperature. Tensile test was performed through Universal testing machine (UTM) which showed that Young’s Modulus mproved from 147.348 MPa for neat sample (TPU-1) to 244.568 MPa for TPU-6. UL-94 test was executed to observe flame retardance. Sample of interest (TPU-6) achieved V-0 classification in UL-94. All these results confirmed the synergistic effect of primary and secondary flame retardants. Optimum increase in flame performance and mechanical strength was observed for TPU-6.