Moisture Distribution Profiles in RT-Cured Glass/\ud Epoxy Laminates of Different Thicknesses

Investigations were carried out on the moisture absorption behavior of RT-cured glass/epoxy composite specimens subjected to 333K/Immersion in distilled water. Different laminatethicknesses (i.e., 0.25–2.25 mm) were studied for comparative evaluation of their moisture diffusion\ud and distribution profiles across the thickness of the composite as a function of the exposure period.\ud Moisture absorption data showed that the equilibrium moisture levels (Mm) remained practically\ud the same for different laminates of the same fiber weight fraction (i.e., 0.62). Further, the times of\ud saturation (tm) increased with the laminate thickness, while the absorption rates (slopes of the\ud absorption curves) showed a reverse trend.\ud It was also found that the Diffusion Coefficient (Dc) values of different thicknesses specimens\ud ranged between 0.28 and 7.81(107) mm2 /sec, indicating a negligible thickness effect on this\ud diffusion parameter. The small variations of Dc (all of the order 107mm2/sec) are attributed mainly\ud to the variations in the edge areas for different thickness laminates