Polymer solutions cover a very broad spectrum of uses, firstly because they are often a necessary step during synthesis, purification (fractionation, precipitation), characterization and even processing, but also because they possess original macroscopic properties that are exploited in many fields of application (coatings, cosmetology, agri-food, petroleum fluids, etc.).
The description of such systems is based on two essential themes: solubility and conformation, which are intimately linked to the notion of linkage. Indeed, the connection between adjacent elements making up the macromolecular chain will lead to a reduction in the degree of freedom of these elements and induce the existence of more or less long-distance interactions that will give polymer solutions very special properties, compared to those of small molecules.
The aim of this article is to take a thermodynamic and statistical conformational approach to polymer solubility and conformation in solution, in order to give the reader a global view of the effects involved and enable him to assess the potential of polymer/solvent systems in relation to the applications sought.
The thermodynamic study of solutions was developed with the aim of extending it to polymer blends and explaining the mixing-demixing phenomena leading to two-phase products or "alloys".