Topological rearrangement-derived homogeneous polymer networks capable of reversibly interlocking: From phantom to reality and beyond

Abstract: The combination of polymers can produce a multicomponent polymeric system, with advanced performance that cannot be achieved by the individual components. An ideal case lies in the creation of all interface materials to maximize the synergistic hybrid effects. Thus far, however, even for the elaborate interpenetrating polymer networks, microheterogeneity is inevitably observed. Herein, we show a conceptual innovative approach to prepare molecular-level interlocking polymer networks by topological reorganization of two immiscible single polymer networks with orthogonal reversible covalent crosslinkages. The conventional phase separation is suppressed as gelation proceeds, and the interlocked networks are further unlocked to a homogenous structure, recovering the original single polymer networks. The resultant interlocking polymer networks show nonlinear improvement in mechanical performance in addition to smart adaptivity like self-healability. An extensible platform technology for bringing in new materials may thus be developed, which is breakthrough in the scope of classic polymer engineering dominated by irreversible covalent chemistry. Furthermore, the long-range interlocked networks themselves are a promising model system for studying soft condensed matter physics.