Engineer a controllable hierarchical dynamic cross-linked network

作者：Liu, Wei; Xu, Chuanhui^*; Chen, Yukun^*

来源：Composites Science and Technology, 2023, 234: 109937.

DOI：10.1016/j.compscitech.2023.109937

• HDCs
• Rubber composites
• Stiffness
• Toughness
• Dynamic properties

The overall performance of rubber is largely governed by its internal cross-linked network structure. However, it remains a major challenge to probe into cross-linked networks associated with their fascinating hierarchy and dynamic characteristics. Herein, we propose a strategy for developing "hierarchical dynamic cross-linked net-works (HDCs)" in rubber composites to circumvent the inherent trade-off between stiffness and toughness while accelerating the dynamic properties of the networks. The robust HDCs enabled by networks union enhances the stiffness, and at the same time improves the toughness by dissipating energy in motion and dissociation of multiple interactions. Moreover, the strong diffusivity of the polymer chains and the dynamic reversibility of the cross-linking sites ensure that the rubber composites can be readily healed and recycled, restoring the original mechanical properties under heating. By means of a model system of carboxylate nitrile rubber (XNBR) material, a healable, recyclable and intelligent responsive rubber composite with simultaneously enhanced stiffness (modulus = 3.20 +/- 0.12 MPa) and toughness (40.9 MJ m-3) is fabricated. The clever design of the HDCs in rubber composites conciliates the stubborn contradiction between reinforcement, self-healing/recycling and functional application, which is expected to impact many fields in elastomer science and engineering.

• 单位
  广西大学