RECENT UNDERSTANDING ON THEORIES OF MOISTURE INGRESSION AND ITS EFFECT ON FRP COMPOSITES

Nowadays fiber reinforced polymer (FRP) composites are in massive demand for applications in diversified fields owing to their unique combination of properties. Despite numerous advantages over conventional metallic materials, polymeric composites suffer from the limitation of being susceptible to degradation when exposed to harsh environmental attacks. During their fabrication, storage and service period, components made up of these polymeric materials are subjected to heat and moisture, when operating under changing environments. Such environmental exposures affect the reliability and predictability of the short-term as well as the long-term properties and also the in-service performance of these components. The fiber/matrix interphase plays a key role in deciding the moisture diffusion kinetics as well as response of the FRP composites to different environments. Although moisture uptake theory and mechanism in polymeric composites has been an active area of research for the last few decades, but still accurate predictability of moisture-absorption kinetics is under question due to complex sorption kinetics and scattered experimental data.