ORGS5-0145
The tunable reactivity of carbamate and urea groups in waste polyurethanes based on Zn catalysis
Topic
GS5. Graduate Student Oral Session V: Sustainable Polymers and Circular Materials
When and Where
Sep 28, 2026
15:48 - 16:00
Room 105
Session Chairs
Taehoo CHANG
Taejun EOM
Chae Bin KIM
Presenter(s)
Lei Yan (College of Chemistry, Sichuan University)
Co-Author(s)
Abstract
Polyurethane (PU) is the world’s sixth largest plastic, but improper disposal of waste PU causes environmental pollution and resource waste. Chemical recycling can efficiently convert waste PUs into chemicals or new materials through selective group cleavage. Selective group cleavage in PUs typically follows the nucleophilic reactivity order: ester > carbamate > urea >> ether1,2. Special nucleophiles can cleave both carbamate and urea groups3,4, or noble metal catalysts can cleave urea groups5, while ester and ether groups remain unreactive. However, the diverse recycling goals demand a wider variety of selective group cleavage methods. This work demonstrates the effect of intenal-/extenal microenvironment of chemical groups on hydrolysis selectivity of PUs at the Zn catalysis. The ether groups in the carbamate groups significantly enhanced its hydrolysis reactivity. By controlling the solubility of the ZnCl₂ catalyst in the solvent, as well as the solvent characteristics (i.e., polarity, intermolecular hydrogen bonding), hydrolysis reactivity of ester, carbamate, and urea groups can be adjusted. We proposed the different hydrolysis mechanisms of these groups in PUs and their mutual influences. Thus, the selective group cleavage in waste PUs can be regulated according to different recycling requirements. It demonstrates the Zn-catalyzed hydrolysis mechanisms and regulation strategies providing a reference for diverse selective group cleavage in recycling of waste PUs.
References:
(1) Zhang, S.; Xu, W.; Du, R.et al. Chem. Eng. J. 2023, 470, 144032.
(2) He, H.-W.; Hu, H.; Du, K.-M. et al. Green Chem 2025, 27 (28), 8467–8491.
(3) Johansen, M. B.; Donslund, B. S.; Henriksen, M. L. et al. Green Chem 2023, 25 (24), 10622–10629.
(4) Zhang, H.; Cui, X.; Wang, H. et al. Polym. Degrad. Stab. 2020, 181, 109342.
(5) Iwasaki, T.; Tsuge, K.; Naito, N. et al. Nat. Commun. 2023, 14 (1), 3279.
References:
(1) Zhang, S.; Xu, W.; Du, R.et al. Chem. Eng. J. 2023, 470, 144032.
(2) He, H.-W.; Hu, H.; Du, K.-M. et al. Green Chem 2025, 27 (28), 8467–8491.
(3) Johansen, M. B.; Donslund, B. S.; Henriksen, M. L. et al. Green Chem 2023, 25 (24), 10622–10629.
(4) Zhang, H.; Cui, X.; Wang, H. et al. Polym. Degrad. Stab. 2020, 181, 109342.
(5) Iwasaki, T.; Tsuge, K.; Naito, N. et al. Nat. Commun. 2023, 14 (1), 3279.
