Preparation and Characterization of Poly(ethylene terephthalate)/Calcium Carbonate Nanocomposites

In order to improve the dispersion and increase the compatibility between nanoparticles and poly(ethylene terephthalate)(PET) matrix,calcium carbonate(CaCO3) nanoparticles were successfully prepared via a carbonization route with polyethylene glycol phosphate 1000(PGP) as the modifying agent.PET/CaCO3 nanocomposites were prepared by further in situ polymerization.The products were characterized by transmission electron microscope(TEM),X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM) and thermo gravimetric analysis(TGA).It was found that PGP was successfully modified on the surface of CaCO3.Compared to the nanocomposite filled with the blank CaCO3,a significant improvement in thermal stability and dispersion was observed with the addition of 0.2%(mass fraction) PGP of the modified CaCO3.Friedman method was used to investigate activation energies of nanocomposites during thermal decomposition.The average of activation energies for PET,PET/blank CaCO3 and PET/modified CaCO3 were 200.58,214.86 and 219.50 kJ/mol,respectively,indicating the modified CaCO3 incurred better thermal stability of PET.