Desorption Behavior of Epoxy/Amine-Coated Polyester Triangular Bar Composites Pre-Exposed to Acid Environment

摘要

Epoxy/amine-coated polyester triangular bar composites were fabricated and exposed to 5 wt% hydrochloric acid (HC1) solution at 40 ℃. The weight loss characteristics of pre-exposed composites in heated air at 40 ℃ under forced convection were studied as function of size, spacing, alignment, and orientation of triangular bars. The diffusion coefficient of composites during desorption increases when the bars are oriented flat and are aligned in parallel. The same result is observed when the size of triangular bars is increased, and when spacing between bars is decreased. These results are attributed to the presence of epoxy/polyester interphase regions, which are more accessible when the triangular bars are oriented flat and aligned parallel, have larger size, and have smaller spacing. These interphase regions are preferred conduits of water during desorption of composites. The diffusion coefficients of composites being higher than the values of epoxy and polyester resins further confirm the effect of interphase regions. Among the factors, orientation of triangular bars has the highest influence on the desorption behavior of epoxy composites.