Thermodynamics Properties and Isothermal Crystallization Kinetics of Carbon Black/Poly(ethylene terephthalate) Composites

Abstract

Thermal properties, crystallization behavior and isothermal crystallization kinetics of poly(ethylene terephthalate) (PET) composites filled with nanophase carbon black (CB) have been investigated by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and wide angle X-ray diffractometer (WAXD). Compared with neat PET, thermal properties of the composites are changed significantly. The crystallization temperature decreases from 393 to 373 K when CB content in the composites increases from 0 to 12.5 wt%, while thermal stability of the CB/PET systems is enhanced as increasing initial decomposing temperature (Td) by 9—11 K. Avrami exponents n are evaluated to be 2.1—2.6 for neat PET and the composites. Carbon black nanoparticles acting as nucleating agent in the composites accelerates the crystallization rate as the decreasing half-time of crystallization (t 1/2), and the crystallinity of the composites is improved largely by addition of CB. The present study reveals several aspects of CB/PET composites crystallization behavior which should be considered when designing future applications of developed CB-filled electrical conductive polymer.