writer：Liang Li, Yingfeng Yu*, Huihuang Su, Guozhu Zhan, Shanjun Li, and Peiyi Wu
keywords：Water diffusion, Epoxy resins, Attenuated total reflection infrared spectroscopy; FT-IR spectroscopy, Generalized 2D correlation spectroscopy, Positron annihilation lifetime spectroscopy.
source：期刊
specific source：Applied Spectroscopy
Issue time：2010年
In the present work, time resolved attenuated total reflection Fourier transform infrared spectroscopy (ATR-IR), near-infrared spectroscopy, and generalized 2D correlation analysis were used to investigate water diffusion processes and the state of water molecules in six different epoxy resins. Positron annihilation lifetime spectroscopy (PALS) experimental results and IR results suggested that water diffusion is controlled by local chain reorientation and bond dissociation of water molecules from epoxy networks. Dynamic mechanical analysis (DMA) results of glass transition temperatures of epoxy resins after immersed in hot water correlated well with the PALS and IR results. In addition, four types of water molecules, termed as nonbonded (S0), single bonded (S1), loosely double hydrogen bounded bonds (S2L) and tightly double bonded (S2T), were detected. It was likewise found, as verified by rough estimation, that water molecules with double hydrogen bonds mostly accomplished diffusion.