Etude des solutions de polymères dans un mélange de solvants au voisonage de leur point critique de démixtion, 1. Système méthanol/cyclohexane/polyvinyl‐2 pyridine

It is shown that small quantities of poly(2‐vinylpyridine) extensively change the coexistence curves of the two liquids methanol/cyclohexane, especially in the vicinity of the critical point of the two liquids. It is possible to observe as a function of temperature two domains of solubility separated by three domains of precipitation when the polymer has a molecular weight 200 000. Moreover the dimensions of the dissolved poly(2‐vinylpyridine) are abnormally high in the region of the critical point of the two liquids.