Transition in swollen polymer networks induced by intramolecular condensation

Abstract

Abstract It is predicted that the net repulsion between the segments of a polymer network and a poor solvent can cause a phase transition marked by a sudden change in the degree of swelling. This is analogous to the “coil–globule” transition recently predicted by Ptitsyn to occur for a macromolecule in solution. The critical conditions for the transition. as well as phase diagrams, are calculated for the gel in free swelling and under uniaxial tension, which facilitates the transition. The transition depends on the gel being formed of chains crosslinked while greatly swollen by a diluent and also having a high degree of crosslinking. It is concluded that it would be difficult to attain the conditions necessary for the transition in the free‐swelling case, but that it should be possible for gel under tension.