a Fourier Transform Infrared Study of Competing Equilibrium in P-Vinyl Phenol) Blends.

In this thesis a Fourier transform infrared (FTIR) spectroscopic study of polymer blends containing poly(p -vinyl phenol) (PVPh) is presented. The characteristics of the intermolecular hydrogen bonding arising from the interaction between the phenolic hydroxyl and carbonyl groups of the different polyacrylates are discussed. The experimental work is focussed primarily on the PVPh with polyacrylate blend systems which include poly(methyl acrylate), poly(ethyl acrylate), poly(n-butyl acrylate), poly(n-pentyl acrylate) and poly(2-ethyl-hexyl acrylate). The infrared bands associated with the intermolecular hydrogen bonding between the phenolic hydroxyl and acrylate carbonyl group are identified. The proportion of hydrogen bonded carbonyl groups in these blends is quantified both as a function of composition and temperature. The effect of the pendant group on the extent of the intermolecular interaction is discussed. The experimental results from this study, including those obtained by other workers, are recast into theoretical phase diagrams via the application of an association model describing binary blends involving hydrogen bonds. The phase diagrams are compared with experimental observations and found to be in broad general agreement. The theoretical predictions of the model with respect to the effect of molecular weight and polymer repeat unit size on the predicted phase behavior is discussed. This study confirms that the phase behavior of polymer blends exhibiting hydrogen bonding can be adequately described by a model employing a competing equilibrium scheme which includes an excess free energy function to account for the specific interactions.