MISCIBILITY AND SPECIFIC INTERACTIONS IN BLENDS OF POLY(HYDROXY METHACRYLATES) WITH POLY(VINYLPYRIDINES)

Poly(4-vinylpyridine) and poly(2-vinylpyridine) were found to be miscible with poly(2-hydroxyethyl methacrylate) and poly(3-hydroxypropyl methacrylate). This miscibility is proved by calorimetric studies in conjunction with infrared analysis of the blends. All blends show a single glass transition which is of a higher value than the glass transitions of the blends calculated on the basis of additive behavior. Furthermore, the variation of the glass transitions of the blends follows the Jenckel-Heusch equation. Infrared studies show that carbonyl, hydroxyl, and pyridine ring peaks undergo important changes which were attributed to hydrogen bonding between the hydroxyl groups in both methacrylates and the basic nitrogen atom present within the pyridine ring. These interactions were observed to be of greater relevance for poly(4-vinylpyridine) than for poly(2-vinylpyridine). Finally, phase transitions were also studied. No phase separation was found for blends having poly(4-vinylpyridine), whereas blends including poly(2-vinylpyridine) show a low critical solution temperature at 140-175-degrees-C.