Isothermal crystallization kinetics of fly ash filled iso-polypropylene composite- and a new physical approach

Composites of pre-mixed fly ash (FA) andisotactic-polypropylene (PP) with varying degree of FA, 0, 20, 45 and 60 wt% were prepared by injection moulding at 483 K. The isothermal crystallization kinetics of the neat PP and composites are calculated using exotherms obtained from differential scanning calorimetry (DSC) at different isothermal crystallization temperatures (T_c) 403, 405 and 407 K. The lowest points of the exotherm peaks were shifted to higher crystallization times in the ranges of 0.75-1.50 min with the increasing of T_c in neat PP and composites regardless of FA percentage addition. The values of Avrami exponent n are found as non-integral number ranges 2<n<4, and the calculated initial crystal thickness values of PP change slightly with increasing super cooling temperature as well as FA content.