The absorption of water in PA is slow at the standard condition (23 °C and 50% RH). The time for reaching equilibrium depends on the type of polyamide and the
The maximum water uptake for VER and the composites immersed for 2500 h at room temperature was 0.76, 6.52, 9.56, 12.37, and 14.62%, respectively. All the composites that were immersed in water for a prolonged period demonstrated Fickian diffusion behavior. When first exposed to water, absorption occurred rapidly.
16TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS 1 Abstract This study investigated the combined effects of water absorption and thermal environment on compression after impact (CAI) characteristics of CFRP laminates. Specimens were immersed in 71℃ water for over 10,000 hours to quantify the ratio of water absorption in the CFRP laminates.
The composite specimens absorbed less water than the resin casting because water absorption by the matrices was the main way in the composites. The composites with a Vf of 44% absorbed more water than the composites with a Vf of 34% because there were more micropores inside the fiber bundles and capillary paths in the higher fiber volume fractions.
Preferential absorption of water at the fiber-matrix interface was noted and it was established that, this effect is significantly greater in glass fiber composites than in the carbon fiber ...
Abstract: The objective of the present work is to study the physical, mechanical and water absorption behaviour of coir fiber reinforced epoxy composites filled with Al 2 O 3 particulates. Composites with different compositions were prepared by varying the length of the fiber and content of fiber using hand lay-up technique.
The water absorption and desorption behaviour of these composites obeyed the classical diffusion theory. The diffusion coefficients of the composites during first absorption were very similar to that for the base resin, suggesting that the water uptake process occur mainly in the resin matrix.
According to Tan et al. (2014), the reduction in water uptake of kenaf fiber- PVOH composites with time is due to the leaching of both PVOH and kenaf fiber.Figure 8 shows that the water absorption ...