Abstract
A number of poly(ethylene terephthalate) (PET) nanocomposites were prepared by in situ polymerization using different amounts (0.5, 1, 2, 3 and 4 wt%) of fumed silica (SiO 2). The polymerization of PET was carried out by the two-stage melt polycondensation method. From DSC studies it was found that the melting point of the nanocomposites was shifted slightly to higher temperatures by the addition of SiO 2 till 3 wt% while for PET–4 wt% SiO 2 nanocomposite the melting point was reduced. As the amount of SiO 2 was increased the crystallization became faster, and there was, also, a shifting of the temperature of the crystallization peak to higher values, this being evidence that SiO 2 can act as nucleating agent. At higher content (3 and 4 wt%) the temperature of the crystallization peak is lower than that of PET–2 wt% SiO 2 due to the formation of crosslinked macromolecules. The activation energy is calculated with the Friedman's method. PET/SiO 2 samples present lower activation energy compared to that of neat PET, except those of PET–4% SiO 2, in which the activation energy have a maximum value for α = 0.8 probably due to the second crystallization peak. Extensive crystallization studies by using Avrami, Ozawa and Malek methods verified that PET and its nanocomposites must be crystallized by two mechanisms with different activation energies taking place in different degrees of crystallization.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
