Reprocessable, Reworkable, and Mechanochromic Polyhexahydrotriazine Thermoset with Multiple Stimulus Responsiveness
Li Chen,
Siyao Zhu,
Innocent Toendepi,
Qiuran Jiang,
Yi Wei,
Yiping Qiu,
Wanshuang Liu
Affiliations
Li Chen
Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Center for Civil Aviation Composites, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Siyao Zhu
Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Center for Civil Aviation Composites, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Innocent Toendepi
Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Center for Civil Aviation Composites, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Qiuran Jiang
Key Laboratory of Textile Science &Technology, Ministry of Education, College of Textiles, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Yi Wei
Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Center for Civil Aviation Composites, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Yiping Qiu
Key Laboratory of Textile Science &Technology, Ministry of Education, College of Textiles, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Wanshuang Liu
Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Center for Civil Aviation Composites, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
Developing recyclable, reworkable, and intelligent thermosetting polymers, as a long-standing challenge, is highly desirable for modern manufacturing industries. Herein, we report a polyhexahydrotriazine thermoset (PHT) prepared by a one-pot polycondensation between 4-aminophenyl disulfide and paraformaldehyde. The PHT has a glass transition temperature of 135 °C and good solvent resistance. The incorporation of dual stimuli-responsive groups (disulfide bond and hexahydrotriazine ring) endows the PHT with re-processability, re-workability, and damage monitoring function. The PHT can be repeatedly reprocessed by hot pressing, and a near 100% recovery of flexural strength is achieved. The PHT can also degrade in inorganic acid or organic thiol solutions at room temperature. The thermally reworkable test demonstrates that, after heating the PHT at 200 °C for 1 h, the residuals can be easily wiped off. Finally, the PHT exhibits a reversible mechanochromic behavior when damaged.