Abstract The kinetics of isothermal crystallization for isotactic polypropylene (iPP) containing different volume fraction (φCB) of carbon black (CB) was evaluated by using differential scanning calorimetry (DSC) at 137.5℃

139.5℃ and 141.5℃ with moderate rates of crystallization.Simultaneous measurements of rheological and conduction behaviors were performed to probe the process of isothermal crystallization in dynamic and static modes.It was found that when CB volume fraction φCB was 0.09

the characteristic time for sharp resistance variation was comparable to those for shape changes in storage modulus (G′) or normal force (FN).At φCB of 0.13 and 0.17 above the upper limit of percolation transition

however

the characteristic time resulted from resistance was much less than those from G′or FN

which could be explained by the formation of the percolation network during the induction period of crystallization.On the other hand

for all φCB and crystallization temperatures

the characteristic time from dynamical method was less than that from the static one

which indicated that the dynamical method was more sensitive to the structural transformation than the static one.It was suggested that rheological and electrical simultaneous measurements endowed us a novel approach to probe the formation of percolation network involving in crystallization of polymer matrix.