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Coloquio ICF_ 10agosto

*** 
Se les invita al COLOQUIO del ICF

Miércoles : 10 de agosto
5:30 pm
Lugar: AUDITORIO DEL ICF

"Comparative kinetic study and microwaves non thermal effects on the 
formation of poly(amic acid) 4,4′-(Hexafluoroisopropylidene)diphthalic 
anhydride (6FDA) and 4,4′-(Hexafluoroisopropylidene)bis(p-phenyleneoxy)
dianiline (BAPHF). Reaction activated by Microwave, Ultrasound and 
Conventional heating."

Abstract 
Kinetic behavior and non thermal effect of poly(amic acid) synthesized from 
4,4′-(Hexafluoroisopropylidene) diphthalic anhydride (6FDA) dianhydride and 
4,4′-(Hexafluoroisopropylidene) bis (p-phenyleneoxy) dianiline (BAPHF) 
diamine in microwave transparent p-dioxane solvent at low temperature of 30, 
50, 70 ºC were studied, under conventional heating (CH), microwave (MW) and 
ultrasound irradiation (US). Results shows that the polycondensation rate 
decreases in the next order MW> US >CH and that the increased rates observed 
with US and MW are due to decreased activation energies of the Arrhenius 
equation. Rate constant for a chemical process activated by conventional 
heating declines proportionally as the induction time increases, however, 
this behavior is not observed under microwave and ultrasound activation. We 
can say that in addition to the thermal microwave effect, a non thermal 
microwave effect is present in the system. 


 Dr. Joaquín Palacios Alquisira
 Fac. de Química ? Universidad Nacional Autónoma de México