Epoxy−Amine Reticulates Observed by Infrared Spectrometry. I:  Hydration Process and Interaction Configurations of Embedded H₂O Molecules

Abstract

This article is the first one of a series devoted to the study of hydration processes in epoxy resins using infrared (FTIR) spectrometry, with a view to eventually determining the role of ambient H 2 O molecules in the degradation of these resins, particularly when they are exposed to irradiation. The starting experiment consists of recording spectra of thin films of these resins which allows us to propose a preliminary assignment of the bands of interest. The second experiment consists of heating these resins. As the main effect of a temperature elevation is to break hydrogen bonds, the analysis of the corresponding spectra enables us to more precisely assign bands which will be of importance in the hydration process. The third experiment consists of hydrating these resins in a humid atmosphere. The pressure of the water vapor of this atmosphere is directly measured in the IR spectra where the corresponding, extremely narrow bands are easily isolated. The analysis of the spectra obtained, after subtraction of these bands due to water vapor, allows us to determine the interaction configurations of H 2 O molecules which are embedded in the resins, that is, the various ways they establish or accept hydrogen bonds to or from hydrophilic groups.

Water transport in an epoxy–phenolic coating

“…However, equilibrium water uptake is primarily determined by the hydrogen bonding capability of the network (polarity) [34][35][36][37][38]. Meanwhile, water in epoxy resins has long been established by FTIR techniques to exist in both a free form (not interacting with the resin), and also in a bound state, hydrogen bonded to polymeric sites [39][40][41][42][43]. This dual nature for sorbed water is supported by an abundance of evidence from simulation [44], dielectric measurements [45][46][47], and fluorescence [48].…”

Influence of alkali-freezing treatment on the solid state structure of chitin

“…13 The bands at around 3440 cm À1 for the OH and NH stretching vibrations became wider and moved towards lower wavenumbers because of the change in intermolecular and intramolecular hydrogen bonds during the alkali freezing process. 18,19 This implies that the association through hydrogen bonding and the crystal structure of chitin was modified after alkali-freezing treatment.…”

Iodine–paint interactions during nuclear reactor severe accidents

“…Liu et al (2002) used attenuated total reflectance and Fourier transform infrared spectroscopy to deduce that for Novolac-cured epoxy polymers, water first hydrogen bonds to hydrophilic functional groups in the polymer and then occupies voids as free water. Ngono et al (1999) used infrared spectrometry to deduce that hydrogen bonding is with the ether oxygen on the phenol group. Mijovic and Zhang (2003) applied molecular simulation and spectroscopic techniques to the issue of hydrogen bonding in the resin.…”