Skeletal Network Enabling New‐Generation Thermoplastic Vulcanizates

Abstract

Upcycling of cross‐linked rubbers is pressing. The introduction of dynamic covalent bonds into the networks is a popular tactic for recycling thermosetting polymers, but it is very challenging to integrate engineering performance and continuous yet stable reprocessability. Based on traditional rubber formulations, herein, a straightforward strategy is presented for constructing a skeletal network (SN) through interfacial crosslinking and percolation of rubbery granules in a rubber matrix. Rapid exchange reactions involving dynamic interfacial sulfides realize repeated “fragmentation and healing” in the solid‐state and consequent reconfiguration of the SN topology of the elastomer, thus endowing the resultant SN elastomer with continuous yet stable re‐extrudability. These SN elastomers with hierarchical structures exhibit high gel contents, high resilience, low creep, and reinforcibility competitive to traditional vulcanizates. Specifically, SN elastomers exhibit better overall performance than commercial thermoplastic vulcanizates (TPVs) materials. Overall, a new concept of thermoplastic vulcanizates is proposed, which will promote the sustainable development of rubbers.

In-Situ Gradient Cross-Linking in Anion Exchange Membranes for Water Electrolyzers

“…The polymer chains of AEMs will gradually disentangle over time due to the water absorption expansion, resulting in excessive deformation and a reduction in mechanical strength. , Cross-linking, as a favorable solution, can make the disentanglement of polymer chains more difficult, thus alleviating the physical failure. − Lee et al prepared AEMs with high dimensional stability by thermal cross-linking, while relatively low conductivity limited the performance of the electrochemical properties . Chen and co-workers designed the in-situ styrene cross-linking membranes to significantly improve the mechanical strength of AEMs.…”

Synthesis, Recycling and High‐Throughput Reprocessing of Phase‐Separated Vitrimer‐Thermoplastic Blends

“…More recently, the same group also extended this strategy to ethylene propylene diene monomer (EPDM) rubbers by incorporating micronized, highly cross-linked sulfur-vulcanized EPDM into uncured EPDM gum. [24] The adjunction of 1,8diazabicyclo [5.4.0]undec-7-ene (DBU) catalyst enabled disulfide exchanges and interfacial percolation across cross-linked domains to form a so-called skeletal network that combines creep resistance with excellent reprocessability.…”