Fourier transform polymer-solvent molecules

Chain polymers are usually plasticized for use as binders. The introduction of a plasticizer promotes good adhesion by increasing the flexibility of the film and allows more poinls of conlacl with the substrate as the solvent evaporates. The configuration of polymer molecules at the surface of a substrate will determine the number of points of contact that can be achieved. Polymer configuration is an aspect of the mechanism of coating adhesion that can be studied by Fourier transform infrared spectroscopy (see Infrared spectroscopy). 

Differential scanning calorimetry and Fourier transform infrared spectroscopy techniques were used to study the structure of water molecules in polyvinyl alcohol and polyethylene grafted acrylate hydrophilic polymers. Varying amounts of water were added to test samples and the samples conditioned to the sorption equilibrium state in sealed containers for 24 hours prior to evaluation. It was concluded that below a threshold water content, depending on the polymers physical and chemical stmcture, water molecules absorbed in hydrophilic polymer cannot form ice crystals in the polymer matrix. Above this threshold content, the water crystallises but below zero. It was also demonstrated that the absorbed water in hydrophilic polymers develops differing hydrogen bonds in the first and second hydration layers. It was concluded that the potential influence of these intermolecular interactions should therefore be taken into account whenever a polymer is used with a solvent. 25 refs. 

---