Impact Of Architecture On The Durability Of Polymer Composite Materials In Hygrothermal Environments

The central objective of my doctoral research is to shed light on the impact of internal structure on moisture-triggered degradation mechanisms across various scales. In particular, my investigation centers on the kinetics of moisture-induced degradation in two distinct polymer composites: Fiber reinforced polymer composites and Flexible syntactic foam. The initial study involved the creation of computational models using a finite element framework to assess the kinetics of moisture diffusion in impermeable fiber-reinforced polymer composites (FRPCs). The introduction of the tortuosity factor served as a means of quantifying the degree of deviation in the pathway of moisture diffusion resulting from the presence of impermeable reinforcement. Subsequently, a correlation between tortuosity and moisture diffusivity was established, paving the way for future applications of composite design and optimization. The information acquired from the preliminary investigations is leveraged to gain insights into the thermal transport characteristics driven by the moisture diffusion pathway in traditional circular fibers, as well as other fiber cross-sectional shapes such as those of the bean, bi-lobular, and triangular varieties. Finally, The impact of extended moisture exposure on the viscoelastic, thermal transport, and dielectric properties of Flexible syntactic foam has been comprehensively elucidated. This study provides valuable insights into optimizing this material at multiple scales, facilitating the attainment of desired properties.