γ-Radiation derived from clean energy has emerged as a promising technology for disposal of waste plastics. However, due to radical-mediated uncontrolled recombination, a foremost challenge remains in radiation-triggered complete degradation for thermoset plastics. Herein, the radiation-sensitive epoxy thermoset (EP-DESN) containing phenyl imine-conjugated N–N bonds (PINN bonds) and S–S bonds was designed to initiate rapid degradation at a dose of 10 kGy. The phenyl imine-conjugated linkages can stabilize the radiation-induced broken N–N bonds, overcoming radical-mediated uncontrolled recombination and cross-linking. Moreover, the phenyl-iminyl-conjugated radicals generated by PINN bond scission can cleave the active S–S bonds to promote subsequent spontaneous degradation for maximum degradation efficiency. Meanwhile, EP-DESN exhibited superior thermal robustness and chemical resistance comparable to some conventional high-performance epoxy thermosets. Using EP-DESN as a binder, we prepared recyclable carbon fiber-reinforced composites, and nondestructive recycling of value-added carbon fiber (CF) is achieved, thus facilitating the concept of a circular CF economy.
源自清洁能源的γ-辐射已成为一种前景广阔的废塑料处理技术。然而,由于自由基介导的不可控
重组,辐射引发的热固性塑料完全降解仍是一项重大挑战。在此,我们设计了一种对辐射敏感的环氧热固性塑料(EP-DESN),它含有苯基
亚胺共轭的 N-N 键(
PINN 键)和 S-S 键,能在 10 kGy 的剂量下快速降解。苯基
亚胺共轭连接可稳定辐射引起的 N-N 键断裂,克服自由基介导的不可控
重组和交联。此外,
PINN 键断裂产生的苯基
亚胺共轭自由基可以裂解活性 S-S 键,促进后续的自发降解,从而实现最高的降解效率。同时,EP-DESN 还表现出优越的热稳定性和耐
化学性,可与一些传统的高性能环氧热固性材料相媲美。利用 EP-DESN 作为粘合剂,我们制备出了可回收的碳纤维增强复合材料,并实现了碳纤维(CF)的无损回收增值,从而促进了碳纤维循环经济概念的实现。