SBS Thermoplastic Elastomer Based on Dynamic Metal‐Ligand Bond: Structure, Mechanical Properties, and Shape Memory Behavior
Qiang Wang, Yu He, Qiuying Li, Chifei Wu
Abstract
Abstract A Cooper(II) (Cu 2+ )‐nitrogen coordination‐crosslinked network is designed in poly(styrene‐co‐butadiene‐co‐styrene) (SBS) to change commercial elastomers into advanced soft materials. Herein, ligand groups into SBS molecular chains by the 3,6‐di(2‐pyridyl)‐1,2,4,5‐tetrazine (DPT) click reaction are first introduced. The results from fourier transform infrared (FT‐IR), 1H‐nuclear magnetic resonance, and X‐ray photoelectron spectroscopy (XPS) are verified the successful modification of SBS. The DPT‐grafted SBS could then coordinate with copper sulfate (CuSO 4 ) to form a Cu 2+ ‐nitrogen bond, which is further characterized using FT‐IR, XPS, atomic force microscope, scanning electron microscope, and geometric structure calculations. After modifying SBS to form an SBS‐DPT/CuSO 4 composite (SBS‐DPT2‐Cu10), the tensile stress is improved from 11.43 to 23.25 MPa, while the elongation at break is remained almost unchanged, and the corresponding toughness is increased from 33.21 to 63.26 MJ m –3 . Moreover, the dynamic nature of the Cu 2+ ‐nitrogen coordination bonds enables the SBS‐DPT/CuSO 4 composite to exhibit sustained thermoplastic performance and excellent shape memory behavior under an external thermal stimulus.