EFFECT OF TETRAPHENYL PHOSPHONIUM MODIFIED MONTMORILLONITE ON THE NON-ISOTHERMAL CRYSTALLIZATION AND THERMAL DEGRADATION BEHAVIOR OF POLY (ETHYLENE TEREPHTHALATE) NANOCOMPOSITES

Poly (ethylene terephthalate) (PET) nanocomposites with different loadings of montmorillonite and tetraphenyl phosphonium bromide (TPP-MMT) as a modifier were prepared using melt-compounding technique and characterized by using XRD patterns and TEM images. The purpose of this work is to investigate the effect of the addition of TPP-MMT on the PET non-isothermal crystallization and its thermal degradation behavior. X-Ray Diffraction (XRD) patterns and Transmission Electron Microscope (TEM) analysis suggested the formation of intercalated nanocomposite structures. On the other hand, TPP-MMT nucleating effect was studied by employing differential scanning calorimetric (DSC) analysis from where it was observed that TPP-MMT behaved as a nucleating agent and enhanced the PET crystallization rate. Nonisothermal crystallization behavior and kinetics of PET/ TPP-MMT were also investigated, by using Avrami and Liu models, based on DSC data. Here it was showed that the nanocomposites exhibited an improvement of their thermal stability. The activation energies Eα of thermal degradation for nanocomposites were found to be higher than that of virgin PET, indicating that TPP-MMT had a stabilizing effect upon the matrix’s decomposition. The TGA kinetic study revealed that the thermal degradation process of pristine PET and its two nanocomposites at 2 and 4% wt obeys the Phase boundary reaction, with n = 2 model, whereas for PET 6% TPP-MMT nanocompossite, the kinetic model is Phase boundary reaction, with n = 3. Since this characterization study supported by various models, which makes the results scientifically sound.