Cure kinetic study of carbon nanofibers/epoxy composites by isothermal DSC

Abstract

An investigation was carried out into the cure kinetics of carbon nanofibers (CNF)/epoxy composites, composed of tetraglycidyl-4,4Ј-diaminodiphenylmethane (TGDDM) resin and 4,4Ј-diaminodiphenylsulfone (DDS) as a curing agent. The experimental data for both neat system and CNF/epoxy composites revealed an autocatalytic behavior. Analysis of DSC data indicated that the presence of carbon nanofibers had only a negligible effect on the cure kinetics of the epoxy. Kinetic analysis was performed using the phenomenological model of Kamal and two diffusion factors were introduced to describe the cure reaction in the latter stage. Activation energies and kinetic parameters were determined by fitting experimental data. Comparison between the two diffusion factors was performed, showing that the modified factor was successfully applied to the experimental data over the whole curing temperature range.

Effects of graphene oxides on the cure behaviors of a tetrafunctional epoxy resin

“…Figure 4 shows the conversions of reaction (") as a function of temperature for neat epoxy and GO/epoxy nanocomposites at a heating rate of 20°C/min. It can be observed that all curves show a sigmoidal form, which indicates that the cure reaction of TGDDM/DDS system is autocatalytic in agreement with our previous studies [17,18]. Consequently, the incorporation of GOs has no influence on the cure reaction mechanism of the TGDDM/DDS system.…”

“…Differential scanning calorimetry (DSC) may be considered as one of the most interesting techniques for kinetic analysis of cure reactions of thermosetting systems [13][14][15]. Numerous studies on cure kinetics of epoxy in presence of carbon-based nanofillers have been investigated [16][17][18][19][20][21][22][23][24][25]. Recently, Allaoui and El Bounia [16] had reviewed the influence of CNTs on the cure kinetics of epoxy resin.…”

“…Recently, Allaoui and El Bounia [16] had reviewed the influence of CNTs on the cure kinetics of epoxy resin. Our previous studies showed that the addition of CNTs could accelerate the cure reaction of epoxy resin, while CNFs had only a negligible effect on the cure kinetics of the epoxy [17,18]. Abdalla et al [19] investigated the effect of carboxyl and fluorine surface modification of multiwalled carbon nanotubes (MWCNTs) on the cure behavior of epoxy resins with the modified CNTs, and reported that the activation energy and rate constant were not affected by the fluorine modification whereas the resins with carboxylated MWCNTs exhibited an increase in the activation energy and a lower rate constant for the cure reaction.…”

Cure kinetics of vapor grown carbon nanofiber (VGCNF) modified epoxy resin suspensions and fracture toughness of their resulting nanocomposites

“…Of all, the most valuable one is carboxylic acid groups. This is because a number of coupling reactions can take place in the presence of carboxylic acid groups, which enables introduction of different types of chemical molecules onto the surfaces of nanofillers [9,10]. However, chemical functional groups grafted onto the surfaces of nanofillers may have some considerable influences on the features of composite processing.…”

“…However, chemical functional groups grafted onto the surfaces of nanofillers may have some considerable influences on the features of composite processing. In particular, they may alter cure kinetics, viscosity and flow behavior of the injected matrix resin in a simultaneous manner [2,[6][7][8][9][10][11][12][13][14][15][16][17][18].…”