Diffusion behavior of water and sulfuric acid in epoxy/organoclay nanocomposites

Abstract

ABSTRACT:The research on polymer-layered silicate nanocomposites is currently an expanding field of study because they often exhibit a wide range of improved properties over their unmodified starting polymers. Epoxy/ organoclay nanocomposites have been prepared by intercalating epoxy into the organoclay montmorillonite. The intercalation and/or exfoliation of the clay within the nanocomposite were monitored using X-ray diffraction and transmission electron microscopy. Diffusion was studied through epoxy samples containing up to 10 phr of organically treated montmorillonite following the gravity method. The water and sulfuric acid diffusion within the epoxy-based nanocomposites were evaluated in terms of diffusivity, weight change and penetration depth of the sulfuric acid element S as function of immersion time and immersion temperature. An investigation of the resistance of epoxy nanocomposite to a corrosive environment by immersion into sulfuric acid at elevated temperature was performed. The effect of the degree of exfoliation of the clay on moisture barrier effect and corrosion resistance is specifically studied. The data has been compared to those obtained from the neat epoxy resin to evaluate the diffusion properties of the nanocomposites. It was found that the diffusion of water and that of acid do not obey Fick's law, and that the higher the organoclay content the higher weight change was obtained. The presence of the organoclay enhanced the diffusivity and delayed the penetration of the sulfuric acid.

Diffusion behavior of water in polyamide 6 organoclay nanocomposites

“…In the initial stage of the absorption, up to approximately M t /M ∞ = 0.5 the increase in mass shows a linear relationship with the square root of time [26][27][28]. As observed, the plot of M t /M ∞ vs. t 1/2 /2l is linear at the initial stage and the diffusivity can be calculated from its slope, hence, the diffusion behavior of water may be considered to follow the Fickian type diffusion.…”

Electron beam modified nylon 6-clay nanocomposites: morphology and water absorption behavior

“…In some reports, it is shown that due to clay incorporation water absorption is decreased, due to increased barrier effects [10,11]. In other literatures, water absorption is shown to increase due to hydrophilicity of clays [12,13]. Crystallinity of polymers is another important participating factor in controlling water absorption properties of polymeric materials.…”

“…There are some literatures on water absorption of polymer/clay nanocomposites, but they are not crosslinked [9][10][11][12][13].…”

Experimental and theoretical investigation of non-Fickian moisture absorption of quartz/BMI laminates fabricated by preconditioned prepregs

“…Moisture absorption behavior and laminate degradation of BMI resin has been addressed occasionally in varying detail [2,[6][7] but not as extensively investigated as fiber-reinforced epoxy laminates [1,[3][4][5][8][9][10][11]. In this paper, the effect of process induced voids on moisture absorption kinetics of HexPly® F650, a bismaleimide (BMI) resin reinforced with 581 style, eight-harness satin weave quartz fabric is investigated.…”