Macromolecular topology. Metastable isomers from pseudo interpenetrating polymer networks

After briefly reviewing macromolecular topological isomers we point out the possibility of obtaining metastable, one phase materials from pseudo interpenetrating polymer networks containing, modest concentrations, of very high molecular weight linear chains or star polymers. We call these examples of metastable macromolecular topological isomers since they are more stable than the usual physical polymer entanglements but very considerably less stable than «permanently» bonded knots, catenanes or interpenetrating polymer networks. We list some properties of these materials which can also be considered as metastable polymeric rotaxanes