Isothermal crystallization kinetics of AB2 hyper-branched polymer (HBP)-filled polypropylene (PP)

Abstract

In this paper, the isothermal crystallization kinetics of pure polypropylene (PP) and AB2 hyper-branched polymer (HBP)/PP blends have been investigated by differential scanning calorimetry (DSC). During isothermal crystallization, the crystallization rates of the blends are higher than those of PP. Furthermore, in the blends with different HBP contents, the value of t 1/2 became smaller with increasing HBP content; however, the crystallization rate of the blend decreased slightly when the content of HBP is 5 %. An increase in the Avrami exponent means the addition of HBP influences the mechanism of nucleation and the growth of PP crystallites. In addition, the crystallization activation energy of pure PP and HBP/PP blends were also discussed, and the result showed that the crystallization activation energy has decreased remarkably in HBP/PP blends.