Effect of Surface Modification on the Dispersion, Thermal Stability and Crystallization Properties of PET/CaCO3 Nanocomposites

Abstract

In order to improve the dispersion and increase the compatibility between CaCO₃ nanoparticles and a polyethylene terephthalate (PET) matrix, hydrophobic calcium carbonate (CaCO₃) nanoparticles were successfully prepared via a carbonization reaction with stearic acid (SA) as the modifying agent. PET/CaCO₃ nanocomposites were prepared by further in situ polymerization of purified terephthalic acid (PTA), ethylene glycol (EG) and CaCO₃ nanoparticles. The surface modification of CaCO₃, the microstructure and the properties of nanocomposites were investigated by water contact angles measurements TEM, FTIR, XRD, SEM, TGA and DSC. SEM examination of the fractured surfaces of nanocomposites showed that CaCO₃ modified by SA achieved well dispersed in the PET matrix. Moreover, compared to the nanocomposite filled with the blank CaCO₃, the resulting nanocomposite filled with the modified CaCO₃ exhibit a better thermal stability and a superior crystallization property.