Experimental study on thermal and mechanical behavior of polypropylene, talc/polypropylene and polypropylene/clay nanocomposites

In the present paper, thermal and mechanical behavior of neat polypropylene, 40 wt.% talc-filled polypropylene and 5 wt.% silicate-clay filled polypropylene nanocomposite were tested and evaluated. TGA and DSC results show that filling the talc particle or nano clay into polypropylene can increase the decomposition temperature, but has no effect on glass transition temperature and melt temperature. Tensile results show that 40 wt.% talc particle can increase the modulus, but decrease the yield strength, 5 wt.% nano clay can improve both modulus and yield strength by 90 and 5%, respectively. Fatigue results show that the nanophased polypropylene exhibited the highest fatigue performance, and fatigue strength coefficient, σf, of nanophased polypropylene was 13.3% higher than that of the neat propyropylene and 50% higher than that of talc-filled polypropylene. At last, a three-parameter non-linear constitutive equation was developed to describe strain rate depend strain softening behavior of three materials.