Li Liang, Chen Yin, Li Shanjun
The Key Laboratory of Molecular Engineering of Polymers, Ministry of Education, and Department of Macromolecular Science, Fudan University, Shanghai, 200433, China.
Appl Spectrosc. 2006 Apr;60(4):392-7. doi: 10.1366/000370206776593717.
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.
在本工作中，合成了具有全氟侧链的线型酚醛树脂，并与邻甲酚醛环氧树脂固化，以获得具有不同氟含量的环氧树脂。采用衰减全反射傅里叶变换红外光谱（ATR/FT-IR）监测这些体系中的原位水扩散过程。水的扩散系数随着氟含量的增加先增大后略有减小，这可归因于全氟侧链引起的两种相反效应：增强的疏水性和增加的自由体积。此外，采用广义二维（2D）相关分析来研究水扩散的吸附和解吸过程，发现了两种水分子，即结合水和自由水。有趣的是，发现在吸附过程中，结合水分子数量的变化比自由水分子数量的变化更早发生，而在解吸过程中，顺序相反。
