Adaptable Interlocking Macromolecular Networks with Homogeneous Architecture Made from Immiscible Single Networks

Abstract

Traditional interpenetrating polymer networks (IPNs) are not adaptable materials because the topological structure of the macromolecules cannot be changed, which limits their structural rearrangement, reprocessing, and recycling. Here in this work we present a strategy for preparing reversibly interlocking networks (RILNs) from two preformed immiscible polymer networks based on dynamic covalent chemistry. The frequently opening and closing of the single networks enabled by the exchange reactions of the embedded orthogonal dynamic covalent bonds and stronger intercomponent interaction mainly account for the formation of the interlocking topology architecture of the RILNs. The resultant RILNs are rather homogeneous, which not only possess stimulus-responsive adaptive performance like self-healing but also exhibit nonlinear improvement in static and dynamic mechanical properties. By taking advantage of the reversible bonding, more importantly, the RILNs can be unlocked reproducing the pristine single networks, and the relocking/unlocking cycling is allowed to proceed for multiple times, which are not available for IPNs as defined by their chemical nature. It is anticipated that the proposed methodology provides a new idea for producing multifunctional cross-linked polymers capable of repeated controlled degradation and regeneration.

Vitrimers: directing chemical reactivity to control material properties

“…Indeed, this concept was exclusively reported by Rong, Zhang and co-workers who combined boronic esters and disulde exchanges in two different yet interpenetrated networks. 75 Thanks to this network interlocking, the phase separation of the two incompatible networks was stabilized generating a single intermediate glass transition. Furthermore, this interlocking also resulted in a nonlinear improvement in static and dynamic mechanical properties.…”

Dually Crosslinked Polymer Networks Incorporating Dynamic Covalent Bonds

“…Another approach for combining two DCBs in an IPN was reported by Rong, Zhang, and co-workers [ 45 ]. A bulk IPN was prepared from two single PUR elastomer networks, with one comprising boronic esters and the other comprising disulfides ( Figure 14 ).…”

“… Dual dynamic bulk IPN comprising disulfide and boronic ester DCBs [ 45 ]. ( a ) Structure of the disulfide (SN-SS) and the boronic ester (SN-PB) single networks.…”

Implementation of the Pulley Effect of Polyrotaxane in Transparent Bulk Polymer for Simultaneous Strengthening and Toughening

“…It is anticipated that the molecular design proposed in this work can be easily applied to other polymers in the form of auxiliaries crosslinkers, [40,41] and a series of new functional materials would be made when the concept is coupled with reversibly interlocked polymer networks (RILNs). [42][43][44]…”