Non-isothermal crystallization kinetics of kaolin modified polyester

Abstract

Fiber-class modified kaolin and PET have been blended in the twin-screw and granulated to chips containing 4 wt% of kaolin. Non-isothermal crystallization process of kaolin modified polyester was investigated using a differential scanning calorimetry (DSC), and the addition of kaolin enhances either the melting temperature (T _m) or the crystallization temperature (T _c). The morphology of kaolin modified polyester, the melt of which is cooled at different cooling rate, was observed by scanning electron microscope (SEM). The relationship between T _c and cooling rate F was studied. Semi-crystalline phase t _1/2 makes an exponential decline with increasing F, and the higher the cooling rate, the shorter the time of crystallization completion. Non-isothermal crystallization kinetics parameters and the activation energy were calculated, indicating that the higher rate of cooling needs the higher relative crystallinity in the unit crystallization time, the crystallization rate increased while speeding up the temperature reduction, and the activation energy ΔE was calculated to be −204.1566 kJ/mol for the non-isothermal crystallization processes by the Kissinger’s methods.

Keywords

kaolin / polyester / crystallization kinetics / non-isothermal

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