Introduction

Water-soluble polymers are widely used in a variety of roles, they are valuable for their ‘thickening’ capabilities in, for example, emulsion paint formulation, and for their adsorption capability in such industrial contexts as emulsion polymerisation. Certain water-soluble polymers, because of their exceptional biocompatibility are used increasingly in the food and drug industries as extenders and prolonged release agents. The increasing concern expressed with regard to contamination of the environment by organic solvent based processes, means that in the future increasing reliance will be placed upon materials which are soluble in water.

Water-soluble polymers in aqueous solution in many ways do not behave in a manner comparable with polymers dissolved in organic solvents, due to the uniqueness of the solvent – water. The high capability of water for hydrogen bonding, its high dielectric constant and the capacity for hydrophobic hydration of non-polar groups, mean that solution behaviour of water-soluble polymers can be quite startlingly different to that of polymers dissolved in organic solvents, one illustrative example being a tendency to precipitate out of solution upon warming!

It is not possible, within the compass of this review, to examine exhaustively the solution behaviour of every kind of water-soluble polymer, it is rather, the intention to highlight the areas in which uniqueness is exhibited, and those where contention as to the explanation for the behaviour exists.