Maximum water absorption and the highest diffusion coefficient were found when mAC was ai 2.0 wt% The water absorption mechanism of the foamed PVC/rice hull composite followed the kinetics of fickian diffusion theory.
A slight increase in both the flexural modulus and the strength was observed in all the PVC/rice hull foam compositions due the leaching of some PVC additives.
microscopic observation on the surface of the foamed composites revealed abundant surface openings depicting the passages of water diffused in the PVC/rice hull foamed composites.