SYNTHESIS CHARACTERIZATION AND MISCIBILITY OF POLYVINYL BUTYRALS OF VARYING VINYL ALCOHOL CONTENTS

Polyvinyl butyrals (PVB) of systematically varying vinyl alcohol conte nt have been synthesized and characterized using wet chemistry, IR, DS C; and TGA. The miscibility of PVB-PVB blends was studied by DSC as a function of vinyl alcohol content and vinyl alcohol content difference s between the respective blend components. These data were use to cons truct an isothermal miscibility map of PVB and to calculate the intram olecular interaction parameter chi(VA,VB) The chi(VA,VB) was a functio n of the absolute level of the vinyl alcohol (VA) and vinyl butyral (V B) contents of the polymers. In addition, the thermal stability of pol yvinyl butyral was found to be inversely related to the residual vinyl alcohol content of the polymer.