Get access

Application of nonisothermal cure kinetics to the interaction of poly(ethylene terephthalate) with alkyd resin varnish



Samples of varnish (V), poly(ethylene terephthalate) from recycled soft drink bottles (PET-R), and varnish/poly(ethylene terephthalate) from recycled soft drink bottles mixtures (VPET-Rs) were evaluated with differential scanning calorimetry (DSC) to verify their physicochemical properties and thermal behavior. Films from V and VPET-R were visually similar. The maximum amount of PET-R that we could add to V without significantly altering its filming properties, such adherence and color in glass sheets, was 2%. The cure process (80–203°C) was identified through the DSC curves. The kinetic parameters, activation energy (E), and Arrhenius parameter (A) for the samples containing 0.5–2% PET-R were calculated with the Flynn–Wall–Ozawa isoconversional method. With greater amounts of PET-R added, there was a small change in E for the curing process. A kinetic compensation effect, represented by the equation ln A = −10.5 + 0.29E, was observed for all of the samples. The most suitable kinetic model to describe this curing process was the autocatalytic Sestak–Berggren model, which is applied to heterogeneous systems governed by nucleation and growth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Get access to the full text of this article