Thermal degradation kinetics of insulating/conducting epoxy/Zn composites under nonisothermal conditions

Abstract

This article deals with the nonisothermal degradation kinetics of insulating and conducting epoxy/Zn composites. A comparison of thermal degradation data obtained from epoxy/Zn composites revealed that the addition of zinc content in epoxy significantly increases its degradation rate. However, the zinc content activates the degradation until its melting point (419.5°C) and then it starts stabilizing the matrix due to its higher specific heat in molten state. Kinetics of the phenomena fairly explains this behavior in terms of the comparison of general kinetic equations for epoxy/Zn composites. It is to notice that both the values of effective activation energy and reaction model (Šestâk Berggren/SB‐m, n) for insulator/conductor composite pair have been found almost the same emphasizing upon negligible polymer–metal interactions in both cases. These mechanistic clues derived from comparative kinetic study have been found in good agreement with the results obtained through morphological analysis of samples by scanning electron microscopy and X‐ray diffraction techniques. POLYM. COMPOS., 34:2049–2060, 2013. © 2013 Society of Plastics Engineers

Thermal degradation mechanisms of epoxy composites filled with tin particles

“…The reason might be a very slight increase in the heat capacity of tin with the increase in temperature contrary to zinc [9]. The heat capacity of tin at room temperature is 0.228 J g 21 K…”

“…The evaluation of nonisothermal degradation mechanisms of electrically insulating/conducting epoxy/Sn composites by using solid-state kinetic approaches is a continuation of our previous studies about epoxy/Zn and epoxy/Al composites [9,10]. In our previous research works, interesting mechanistic information and new insights into the mentioned composites have been obtained [9,10].…”

“…The filler is a commercial powder of b-tin (Sn), delivered by Panreac (Castellar del Vallès, Spain) with about 97% purity, 7.29 g cm 23 density, 15 6 10 lm average particle size, and electrical conductivity of the order of 10 4 S cm 21 . All the composites have been prepared by following the same procedure, as described in the previous studies [9,10]. Metallic powders were introduced in the fluid resin in calculated quantities and dispersed manually in order to obtain the homogeneity.…”

“…In our previous research works, interesting mechanistic information and new insights into the mentioned composites have been obtained [9,10]. In this study, the nonisothermal degradation kinetics of conducting and nonconducting epoxy/Sn composites will be carried out and the degradation mechanisms will be predicted by advanced reaction model determination methodology.…”

Recent Progress in Kinetics of Thermal Degradation Mechanisms in Polymer Composites

“…They may either be insulating or conducting, though both of them are equally useful. Insulating composites are applicable as thermal greases, thermal interface materials, and electric cable insulations, while conductive composites are exploited in thermo electrical and thermo mechanical applications, and organic electronics [1,[2][3][4][5][6]. However, in order to continue satisfying the global demands (particularly of energy), there are certain issues which need to be addressed regarding the polymer composites [7].…”