Tailoring the crystallization, viscoelastic, and thermal degradation properties of polypropylene by nano-tungsten carbide and multiwalled carbon nanotubes

The study investigates the individual and collaborative effect of tungsten carbide (WC) and multi-walled carbon nanotubes (MWCNTs) on the surface characteristics, viscoelastic, and thermal properties of polypropylene (PP). The uniform dispersion of dual nanofillers was observed from TEM analysis, and the surface topography was revealed using atomic force microscopy (AFM). From the dynamic mechanical analysis (DMA), the hybrid sample (1 wt% WC and 2 wt% MWCNT) exhibited the highest storage modulus (75% increase at 20 degrees C compared with PP) and was further verified by several theoretical models. The Cole-Cole plot of the hybrid composite sample exhibited deviation from the semi-circle geometry due to the effective mixing of nanofillers in the matrix. The sample also manifested the highest creep resistance and 67% reduction in critical creep rate compared to neat PP. XRD and DSC analysis revealed that P/1W/2C sample has more thermodynamically stable alpha crystals. The thermal analysis showed that rapid cooling resulted in the formation of imperfect and non-uniform crystals. The hybrid sample showed impeccable thermal degradation resistance with the lowest weight loss rate and the highest activation energy (say at 10 degrees C/min, Tmax: 472 degrees C, Ea: 269 kJ/mol).Highlights Investigated the combined effect of WC and MWCNT bi-nanofillers in the PP matrix. Explored the surface roughness of the composite by AFM. Evaluated the mechanical, and viscoelastic behavior of PP nanocomposite. Estimated Ea for thermal degradation of PP nanocomposites using different models. Demonstrated the effect of cooling rate on crystallization by DSC analysis.