Free radical bulk polymerization of methyl methacrylate (MMA) was carried out in the presence of a macrocyclic amine based on cyclic polystyrene. The polymer changed to an insoluble solid upon heating at 180 degrees C in a vacuum. The insolubility is attributed to the in situ formation of a polypseudorotaxane, followed by the covalent fixation of the threaded ring segment with the linear chain to form a noncovalent three-dimensional structure.