Zhang Ruize, Zhong Jiaqi, Wu Gaosheng, Xu Kaidi, Xu Xiaoli, Cui Xuliang, Xu Baoyun, Li Xiaolei
Shanghai Research Institute of Chemical Industry, Shanghai, People's Republic of China.
R Soc Open Sci. 2025 Jul 9;12(7):250109. doi: 10.1098/rsos.250109. eCollection 2025 Jul.
The development of recyclable bio-based epoxy resins has been the focus of research nowadays, particularly in light of increasing environmental concerns and the drive for resource recycling. Herein, two fully bio-based epoxy curing agents, VLYS (fully bio-based Schiff basic epoxy curing agent based on vanillin and lysine) and VLEV (fully bio-based Schiff basic epoxy curing agent based on vanillin and levodopa), were synthesized by reacting amino acids-lysine and levodopa, respectively-with vanillin. Both epoxy resins cured by these two hardeners, VLYS-E and VLEV-E, show high glass transition temperatures ( > 141°C) and superior mechanical properties (Young's modulus >1000 MPa and flexural modulus >2900 MPa), which are far better than the resin system based on a petroleum-based curing agent. The incorporation of the Schiff base endows these resins with degradability and reprocessability, while exhibiting high-percentage retention of thermal and mechanical properties after two cycles. Taken together, these findings suggest that these fully bio-based curing agents hold significant potential to supplant conventional hardeners.
如今，可回收生物基环氧树脂的开发一直是研究的重点，尤其是考虑到日益增长的环境问题以及资源回收利用的需求。在此，通过分别使氨基酸（赖氨酸和左旋多巴）与香草醛反应，合成了两种完全生物基的环氧固化剂，即VLYS（基于香草醛和赖氨酸的完全生物基席夫碱环氧固化剂）和VLEV（基于香草醛和左旋多巴的完全生物基席夫碱环氧固化剂）。由这两种固化剂固化的环氧树脂VLYS-E和VLEV-E均显示出高玻璃化转变温度（>141°C）和优异的机械性能（杨氏模量>1000 MPa，弯曲模量>2900 MPa），这远比基于石油基固化剂的树脂体系要好。席夫碱的引入赋予了这些树脂可降解性和可再加工性，同时在两个循环后仍表现出高比例的热性能和机械性能保留率。综上所述，这些发现表明这些完全生物基固化剂具有取代传统固化剂的巨大潜力。
