Advanced isoconversional cure kinetic analysis of epoxy/poly(furfuryl alcohol) bio‐resin system

Abstract

Furfuryl alcohol as a biomass-derived monomer was used for synthesizing poly(furfuryl alcohol). A diglycidyl ether of bisphenol A (DGEBA) epoxy resin along with 3% and 15% by weight of the poly(furfuryl alcohol) was cured using an aliphatic amine hardener. The cure kinetics of the DGEBA/poly(furfuryl alcohol)/amine systems were investigated by nonisothermal differential scanning calorimetry. The kinetic triplets [E a , A a , and f(a)] were computed by using an integral isoconversional method. Based on the E a -dependency results a single-step autocatalytic model was suggested for the reactions mechanism, however, the A a -dependency and f(a) analysis did not confirm the suggested model. Detailed kinetics analysis revealed that the cure reaction mechanism of the DGEBA did not change due to the presence of the poly(furfuryl alcohol) in the degree of conversion range < 0.75, nevertheless, it dramatically changed in the degree of conversion range > 0.75 due to the presence of 15 wt % poly(furfuryl alcohol). V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45432.

Reliability evaluation of a new method developed for DSC curing kinetic model of epoxy resin

“…On the basis of phenomenological kinetic studies, the cure kinetic methods can be divided into model-free (isoconversional) and model fitting kinetic methods. 12,16,17,38,39 In model-free method, the kinetic parameters can be evaluated as a function of the curing degree, while in the use of model fitting method the parameters are obtained by linear or nonlinear mathematical optimization. 39…”

“…A wide range of the curing kinetic models proposed can be categorized into mechanistic and phenomenological models. Phenomenological models are more appropriate to be employed since it is difficult to access mechanistic models due to the complicated chemical reaction process 3,11,12 . Among phenomenological models, the n ‐order reaction model is the simplest to interpret the curing behavior, which is used extensively as well as the autocatalytic model.…”

“…Phenomenological models are more appropriate to be employed since it is difficult to access mechanistic models due to the complicated chemical reaction process. 3,11,12 Among phenomenological models, the n-order reaction model is the simplest to interpret the curing behavior, which is used extensively as well as the autocatalytic model. M alek and least squares regression (LSR) methods can be used in the autocatalytic reaction model.…”

“…It is well known that the evaluation of cuing kinetic parameters depends on the curing degree, the initial value of which is generally 0.1 3,[13][14][15]18,19,[29][30][31][32] or 0.2 33,34 or minimum value increment. 12,16 Due to the incapacity of Kamal-Sourour kinetic model for predicting cure behavior at the beginning stages of reaction, although the influence of different initial curing degrees on the accuracy of predicted values of the curing degree and time has been discussed, the initial curing degree is assumed as a very small nonzero initial value to be considered as the curing degree at the end of induction time, the maximum of which is 0.01. 27 The common in the investigations is that the attention is paid to providing the accurate curing kinetic behavior of resin exhibiting advantages in some respects, focusing on the curing characterizations and reaction mechanisms of materials themselves.…”

“…To investigate the curing kinetics of resin, several experimental techniques have been used such as thermogravimetry analysis (TGA), [22][23][24]32,34 rheology, 2,19,29,35 differential scanning calorimetry (DSC). 3,[11][12][13][14][15][16][17][18][19][20][21]24,25,30,31 Among the techniques for determining the degree of conversion, TGA is performed by analyzing biomass decomposition. The data obtained from registering weight loss can be used to estimate the degree of conversion of biomass from solid to volatile state.…”