Effect of organically modified montmorillonite filler on the dynamic cure kinetics, thermal stability, and mechanical properties of brominated epoxy/aniline formaldehyde condensates system

Abstract

Nanocomposites, based on tetrabromo-bisphenol-A epoxy and aniline formaldehyde condensates, containing 5 and 10 % organically modified montmorillonite (O-MMT), were prepared. The morphologies of these nanocomposites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The influences of O-MMT on the dynamic cure kinetics, thermal stability, and mechanical properties were investigated by differential scanning calorimetry, thermogravimetric analysis, and non-destructive ultrasonic testing techniques. The XRD and SEM results indicated a good dispersion of O-MMT within the epoxy matrix. The relation between the activation energy, E a, and the degree of cure, α, for the examined systems was obtained by applying model-free isoconversional Kissinger–Akahira–Sunose method. As α increases, E a increases gradually, almost independent of the amount of O-MMT. The dynamic cure kinetics of the neat epoxy system as well as its nanocomposites were described by Sestak–Berggren, [SB (m, n)], autocatalytic model. The O-MMT enhances the thermal stability of the examined epoxy system. The results of the mechanical properties indicated that the addition of O-MMT enhances the Young’s and shear elastic modulus and microhardness. The values of these parameters increase with increasing O-MMT loading.