Influence of Degassing and Nanoclay Loading on Physical and Flexural Properties of Epoxy

Abstract

The mechanical and physical properties of epoxy-clay nanocomposites are known to be significantly affected by the dispersion and distribution of the clay particles in the epoxy matrix. The degree of dispersion of the clay particles in the epoxy matrix depends mainly on the processing parameters used to synthesize the nanocomposite.In this paper, the optimized high shear mixing parameters determined in an earlier work were used to disperse five different loadings of Nanomer I.30E nanoclay (1, 1.5, 2, 3 and 5 wt%) into DGEBA epoxy matrix. A systematic approach was adopted to optimize the degassing process of the mixture. X-Ray Diffraction (XRD) analyses showed that the optimum nanoclay dispersion was achieved for a degassing temperature of 120 °C. The flexural strength of the developed nanoclay/epoxy composite is found to increase by 15% for 1.5 wt% and due to the high stiffness of the clay, as compared with epoxy resin, the flexural modulus improved continuously with clay loading. The observed reduction in strength and fracture strain at high clay loadings is mainly attributable to the presence of clay agglomerations and voids formation. The diffusion of water molecules and maximum moisture uptake of epoxy are reduced considerably by the presence of nanoclay.

The effect of nanomodified epoxy on the tensile and flexural properties of Napier fiber reinforced composites

“…Cracks usually initiate in these preferred zones, which results in early or premature failure of the nanocomposites during the mechanical tests, thus suggesting the lower mechanical properties of the developed composites at 10 wt% clay loading. Ali et al also made a similar inference in their study.…”

Mechanical and Moisture Barrier Properties of Epoxy–Nanoclay and Hybrid Epoxy–Nanoclay Glass Fibre Composites: A Review

“…The selection of the right curing agent and the right quantity is a critical task as it determines the structure and properties of epoxy-clay nanocomposite [16]. Along with the curing agent, several other factors are to be considered during curing such as degassing time and temperature, as well as curing time and temperature [47,57,58]. Pre-curing time and temperature have a significant effect on crosslinking of samples [57].…”

“…However, the effect of pre-curing temperature is found to vanish when post-curing at high temperature is used [57]. With regards to degassing, some efforts [58] have shown that increasing degassing temperature and time can enhance the diffusion of epoxy into intergallery of nanoclay platelets.…”

A two-parameter approach to assessing notch fracture behaviour in clay/epoxy nanocomposites

“…Furthermore, the behaviour of the produced nanocomposites is known to be that of brittle materials [1,5,35].…”

“…type samples of neat epoxy and epoxy-clay nanocomposites containing clay loadings of 3 (NC 3%) and 5 wt% (NC 5%) were fabricated. The nanocomposites were prepared according to the optimised curing and degassing conditions and high shear mixing technique developed in an earlier work[1,5,[33][34][35]. XRD, SEM and TEM analyses have revealed that these optimised conditions result in an epoxy/clay nanocomposite with a combination of disordered intercalated and exfoliated morphology.…”