Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Chemical and Biomedical Engineering

Committee Chair

Rakesh Gupta.


Fiber reinforced plastics (FRPs) are used to make aircraft structures, highway bridges, automobile components, storage tanks, boat hulls, truck beds, and so on. When these FRPs are exposed to the atmosphere, environmental humidity can weaken the structural integrity and cause fiber delamination. The use of glass-fiber-reinforced nanocomposites made by addition of nanoclay, reduces the fiber damage and delamination because of its ability to enhance the barrier property of the matrix material. Clay not only acts as a barrier toward moisture diffusion, it also sequesters the moisture and protects the glass surface. During the course of this study the role of nano and micro fillers such as Montmorillonite clay, carbon nanotubes and Kevlar(TM) pulp in decreasing the diffusion coefficient for steady-state moisture transport through vinyl ester-based composites was quantified. Effects of temperature, concentration gradient, filler-type, filler content, extent of filler dispersion, filler orientation, and moisture adsorption on the filler surface were studied. It was found that nano and micro fillers bring about a decrease in diffusivity of vinyl ester composites, but the decrease is not as substantial as predicted by available equations in literature. An attempt was also made to evaluate the applicability of existing models in quantifying the decrease of diffusion coefficient for nanocomposites. It was found that the models developed during the course of this work were more effective in predicting the experimental results then the existing models.