JAQUES, N. G.; JAQUES, NICHOLLAS GUIMARÃES; GUIMARÃES, NICHOLLAS.; http://lattes.cnpq.br/0970774901803076; JAQUES, Nichollas Guimarães.
Abstract:
Epoxy compounds based on diglycidyl ether bisphenol A/methyl tetrahydrophthalic
anhydride/2,4,6-tris (dimethylaminomethyl) phenol (DGEBA/MTHPA/DEH 35) were
produced adding different concentrations of synthetic catalyser DEH 35; structural
components of eggshell were investigated as natural catalyser. Analyzes of Fourier
transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and
thermogravimetry (TGA) were conducted in order to obtain related results to reactions
and chemical interactions; thermal stability; curing kinetics and degradation kinetics.
FTIR spectra provided evidences of curing and degradation reactions can be
monitored by changing characteristic bands, corroborated results by DSC and TG
thermograms. Using Beer-Lambert Law affords determining the degree of curing and
phase transition, i.e., active centers production, gelation and vitrification. Kissinger,
Friedman isoconversional, Autocatalytic Friedman and Málek models were used in the
curing kinetics investigation, the kinetic parameters were determined from DSC scans,
and Friedman models presented best fits. Degradation kinetics was investigated by
TG applying Kissinger, Friedman, Coats-Redfern and Servant models; best fit was
verified with Friedman model. Among used catalyzers, DEH 35 and eggshell
membrane (M) rendered improved results. Reported results in this work provide
reliable tools to control the curing and degradation processes of epoxy compounds,
enabling their use in laboratory scales, i.e., scientific research, as well as industrial
processes.
