New insights into the cold crystallization of filled natural rubber

This article is devoted to the cold crystallization of filled natural rubber with different types of filler such as carbon black, silica, and grafted silica. A large set of differential scanning calorimetry data is presented with various scanning rates, times, and temperatures of isothermal crystallization to display the factors affecting natural rubber (NR) crystallization. The crystallization kinetic measurements suggest that fillers can create a region with perturbed mobility where the kinetics of nucleation and/or growth are slowed down, the rest of the matrix being unperturbed. And, the final crystallization level indicates the existence of an excluded region for crystallization close to the filler surface. Furthermore, the presence of fillers appears less unfavorable to NR crystallization than chemical crosslinking. (c) 2007 Wiley Periodicals, Inc.