Dynamic cross-linked topological network reconciles the longstanding contradictory properties of polymers
Zekai Wu, Chengzhen Chu, Yuhui Jin, Lei Yang, Bo Qian, Yuepeng Wang, Yihan Wang, Jiani Wu, Yujie Jia, Wenwen Zhang, Zhengwei You
Abstract
There is usually a trade-off between high-tensile properties and processability in polymers because the mechanisms of these properties are mutually exclusive. Here, we design a chemically coupled four-arm dynamic polymer cross-link site to overcome this challenge. By concurrently increasing cross-link sites and dynamic bond contents, this approach fabricates polymer networks with high cross-link density yet low processing temperature, challenging the conventional structure-property relationship where cross-linking inherently limits plasticity. Notably, the material demonstrates remarkable processability, evidenced by the ratio of G ′ max to G ′ min with a temperature differential (Δ T ) of 120°C (which signifies the soft-to-hard transition capability). This ratio reaches 153.3, higher than all reported cross-linked polyurethanes. This work represents a molecular strategy that combines electronic effect and topology network design to modulate materials’ properties, and it will be useful for developing next-generation materials.