Readily Recyclable Thermosets Based on Dynamic Covalent Bonds

Thermosetting polymers have played an important and irreplaceable role, such as adhesives, coatings, composites, etc., while they are difficult to be recycled due to their permanent crosslinked networks. The last few years have witnessed the rapid development of thermosetting polymers based on dynamic covalent bonds, also known as covalent adaptable networks (CANs), which could be easily recycled (reprocessable, weldable or even degradable). The need to develop easily recyclable thermosetting polymers based on dynamic covalent bonds, as well as a summary of the research progress is highlighted in this chapter. The easily recyclable thermosets are divided into three categories based on: (1) the dynamic associative exchange reaction, (2) the dynamic dissociative exchange reaction or (3) two mechanisms together exchange reaction. The recycling methods and mechanisms, and research progress of each category of recyclable thermosets are described in this chapter, as well as the applications of the recyclable thermosets are also summarized. Finally, the conclusions and perspectives are highlighted.