Gelation of polymer solutions as a rheological phenomenon (mechanisms and kinetics)

Abstract

The phase equilibrium shift caused by changes in polymer-liquid compatibility under the influence of external or internal factors is discussed as the main mechanism of gel formation. Wherein, it is assumed that the gel is a solid, non-flowing soft substance formed due to incomplete phase decomposition of a solution. The sol-gel transition occurs through the intermediate stage of the formation of a viscoelastic yielding medium. The liquid-yielding medium-gel transition results in fundamental changes in the rheological properties of the substance. Therefore, the study of the kinetics of the evolution of rheological properties at various stages of gelation is an important tool for understanding this phenomenon. The review contains a discussion of recent publications and the formulation of some challenging problems.