Disclosed are new polymeric materials that respond to a mechanical force. The novel polymeric compounds contain an isomer of aziridine, a three-membered N-heterocyclic compound. Also disclosed are methods for preparing the polymeric compounds. Mechanical force-induced cycloaddition of aziridines as mechanophores yields stereospecific products without covalent bond cleavage of aziridines. That is, a mechanical force makes the mechanochemical products stereospecific. The stereospecific products prepared from the isomeric mechanophores by a mechanical force can be widely used in various industrial fields, including new materials.