Hemiaminal dynamic covalent networks with rapid stress relaxation, reprocessability and degradability endowed by the synergy of disulfide and hemiaminal bonds

Siyao Zhu; Yan Wang; Jiaxin Qin; Li Chen; Liying Zhang; Yi Wei; Wanshuang Liu

doi:10.1039/d3ra05413f

Hemiaminal dynamic covalent networks with rapid stress relaxation, reprocessability and degradability endowed by the synergy of disulfide and hemiaminal bonds

RSC Adv. 2023 Oct 2;13(41):28658-28665. doi: 10.1039/d3ra05413f. eCollection 2023 Sep 26.

Authors

Siyao Zhu^{1

2}, Yan Wang³, Jiaxin Qin^{1

2}, Li Chen^{1

2}, Liying Zhang¹, Yi Wei¹, Wanshuang Liu¹

Affiliations

¹ Shanghai High Performance Fibers and Composites Center (Province-Ministry Joint), Shanghai Key Laboratory of Lightweight Composite, Center for Civil Aviation Composites, Donghua University 2999 North Renmin Road Shanghai China weiy@dhu.edu.cn wsliu@dhu.edu.cn.
² Key Laboratory of Textile Science &Technology, Ministry of Education, College of Textiles, Donghua University 2999 North Renmin Road Shanghai 201620 China.
³ College of Materials Science & Engineering, Donghua University 2999 North Renmin Road Shanghai 201620 China.

Abstract

This work proposes a strategy to address the challenge of achieving rapid reprocessability of vitrimers at mild temperatures by introducing dynamic disulfide and hemiaminal bonds into hemiaminal dynamic covalent networks (HDCNs). The resulting HDCNs, termed HDCNs-DTDA, were prepared through a facile polycondensation between formaldehyde and 4,4'-dithiodianiline. The dual dynamic bond system in the HDCNs-DTDA enables rapid stress relaxation under mild temperature (65 °C for 54 s), which is significantly faster than that observed in HDCNs containing a single dynamic bond (HDCNs-DDM). The HDCNs-DTDA also exhibit a glass transition temperature of 96 °C, excellent solvent resistance and high recovery rates (97%) of tensile strength after reprocessing. In addition, HDCNs-DTDA can be easily degraded in HCl and thiol solutions at room temperature to enable chemical recyclability. Finally, HDCNs-DTDA demonstrates fast shape memory behaviors using thermal stimulation.