Theoretical Study of Network Formation and Mechanical Properties of Physical Gels with a Well-Defined Junction Structure

Theory of transient networks with a well-defined junction structure

The present study constructs a theory of physical gels consisting of bifunctional molecules, f-functional molecules, and solvent. This theory considered the formation of loops (i.e., the smallest cycles). First, the association state in the equilibrium state was investigated. Unlike the previous theory proposed by the authors, the present theory was able to describe the effect of functionality on the association state. Second, the dynamics of gelation was studied. As a result, the authors found two regimes: one where the characteristic time of gelation is governed by the association of associative groups and another where it is governed by the dissociation of them. Finally, theoretical results and the existing experimental results were compared in terms of gelation time and the time development of elasticity. With parameters set reasonably, the theory succeeded in the quantitative description of the experimental results.