writer：Sheng Wang, Songqi Ma, Qiong Li, Xiwei Xu, Binbo Wang, Wangchao Yuan, Shenghua Zhou, Shusen You, and
keywords：vitrimers, epoxy resins, thermosets, bio-resources
source：期刊
specific source：Green chemistry
Issue time：2019年

Epoxy resins have been widely used in a multitude of areas including carbon fiber composites, while they are arduous to be recycled. In this paper, for the first time, a Schiff base epoxy thermoset combining excellent recyclability and high performance was facilely prepared from a synthesized formyl group-containing vanillin-based monoepoxide and a diamine via in-situ formation of Schiff base structure and epoxy network. The chemical structure of the monoepoxide and its cross-linked network were characterized in detail. The thermal and mechanical properties, recyclability of the thermoset as well as its application in carbon fiber composite were systematically investigated. Results showed that the thermoset possessed similar glass transition temperature of 172 oC, tensile strength of 81 MPa and modulus of 2112 MPa, and higher thermal stability with the degradation temperature for 5% weight loss of 323 oC and elongation at break of 15% in comparison with bisphenol A epoxy resin. Meanwhile, it exhibited superior reprocessing recyclability due to the vitrimers’ or CANs’ nature of Schiff base network. Furthermore, it could also be completely degraded under mild acidic conditions leading to the ready and nondestructive recycle of its carbon fiber composite.