Comparative curing kinetics study of high char yield formaldehyde- and terephthalaldehyde-phenolic thermosets
Résumé
Phenol-Formaldehyde (PF) resoles exhibit excellent thermal properties, high temperature degradation and high char yield. The formaldehyde can be replaced by terephthalaldehyde (TPA), a non-toxic aromatic dialdehyde. The thermal performances of phenol-TPA (PTPA) resole are very interesting for further development and industrialization. The present investigation presents for the first time a thermo-kinetics study of curing of PTPA, in comparison with a commercial PF resole. Non-isothermal, at constant heating rates DSC experiments are performed on both resoles. PF shows one single exothermic peak, whereas PTPA exhibits two DSC peaks, suggesting a two-step curing mechanism which appears to be conversion-dependent. In addition, isoconversional analysis is used to elucidate the activation energies as a function of the degree of curing. Differential Friedman and integral Vyazovkin methods are considered for computations, giving equivalent results. Furthermore, the whole kinetic triplets (E, A, f) is elucidated for both resoles with Sestak-Berggren model fitting. Finally, isothermal isoconversional predictions are compared to experimental data.
Domaines
Polymères
Origine : Fichiers produits par l'(les) auteur(s)
Loading...