Lysine-based curing agents: A green synthesis strategy for photoluminescent epoxy resins with novel lactam side groups

Abstract

The performance of polymer materials is largely determined by the structures of their side groups, such as alkyl, aromatic, or ester ring groups. Therefore, the development of polymers with novel side groups is of great significance in the field of new functional polymers. To date, polymers containing lactam ring side groups have not been reported. In this study, a bio-based amino-caprolactam epoxy curing agent was successfully used to prepare polyether amine epoxy resin with lactam side groups. The results showed that the addition of the amino-caprolactam curing agent increased the glass transition temperature, char residue, tensile strength, and hardness of the polyether amine epoxy resins. Additionally, this epoxy resin possessed good photoluminescence properties due to the lactam side groups, and its application in coatings and adhesives was investigated. It was found that this epoxy resin can serve as a protective barrier against harmful short-wavelength ultraviolet and high-energy blue-violet light (380–500 nm). Furthermore, due to the unique lactam bond structures, this polymer is expected to have tremendous potential for preparing new functional materials through the ring-opening reaction of lactam groups, such as polyelectrolyte materials and chain extenders for polyamides and polyesters.