The following is an abstract for the selected article. A PDF download of the full text of this article is available here. Members may download full texts at no charge. Non-members may be charged a small fee for certain articles.

Water Diffusion Behavior in Epoxy Resins with Various Fluorine Contents

Volume 60, Number 4 (April 2006) Page 392-397

Li, Liang; Chen, Yin; Li, Shanjun

In this work, novolac resin with perfluorinated side chains was synthesized and cured with o-Cresol novolac epoxy resin to obtain epoxy resins with various fluorine contents. Attenuated total reflection Fourier transform infrared spectroscopy (ATR/FT-IR) was used to monitor the in situ water diffusion process in these systems. The diffusion coefficient of water first increased and then slightly decreased with increasing fluorine content, which could be attributed to two opposite effects induced by perfluorinated side chains: enhanced hydrophobicity and increased free volume. In addition, generalized two-dimensional (2D) correlation analysis was employed to investigate both the sorption and the desorption process of water diffusion, and two kinds of water molecules, named bound and free water, were found. It was interesting to find that in the sorption process, the change in the population of bound water molecules occurs earlier than the change in the population of free water molecules, while in the desorption process, the sequence was reversed.