Degradable Melamine-Based Adhesives Using Dynamic Silyl Ether Bonds

Abstract

Materials made from covalently cross-linked polymer networks are ubiquitous in everyday life but are difficult to process at the end of their life cycle. Therefore, it is essential to design materials with sustainability in mind to reduce the detrimental effects of plastic waste buildup. Functionalized triazines such as 1,3,5-triazine-2,4,6-triamine (melamine), hexamethylolmelamine (HMM), and hexakis(methoxymethyl)melamine (HMMM) are key components of robust thermosets, adhesives, and coatings. We combine HMM and HMMM with an alkoxysilane to produce transparent thermosets with remarkable glass adhesion. The dynamicity of silyl ether bonds in the network makes the materials susceptible to methanolysis, enabling the recovery of HMMM and the substrate. A combination of solution- and solid-phase techniques is used to elucidate both gelation and degradation pathways.