Reversible matrix materials based on associative covalent adaptable networks

Reversible matrix materials based on associative covalent adaptable networks

In this lesson, reversible polymers based on associative covalent adaptable networks, often referred to as vitrimers, are presented and discussed. In the first part, the fundamental chemical mechanisms underlying the dynamic covalent bonds that characterize vitrimers are illustrated in detail, with particular attention to exchange reactions such as transesterification, disulfide metathesis, and transamidation. Then, their peculiar rheological behavior is analyzed, emphasizing the relationship between bond exchange dynamics and the characteristic transition temperatures of these polymers. In the second part of the document, the focus shifts toward the reprocessing and recycling strategies that can be applied to vitrimers exploiting their dynamic network. Various experimental techniques are presented, highlighting the methodology required to perform multiple processing cycles without initiating degradation. The expected results from these approaches are finally discussed, highlighting how vitrimers can contribute to circular economy models of resin and composites by enabling repairability, recyclability, and extended material life without compromising functional properties.