Epoxidation of pillar[5]arene with three dimensional macrocyclic structure and host-guest capability for epoxy coatings

To expand the properties of epoxy coatings for emerging technologies, herein, a pillar[5]arene-based epoxy compound (PAEP) containing unique pillar-shaped three dimensional macrocyclic structure was prepared and cured with conventional 4,4′-diaminodiphenylmethane (DDM). Interestingly, the PAEP exhibited a strong host-guest complexation with 1,4-dibromobutane (DBrBu), a potential organic antibacterial agent, with a complex constant of 215.7 ± 11.02 M −1 . Furthermore, the PAEP/DDM resin possessed enhanced mechanical and thermal properties, probably due to the increase of chain-entanglement brought about by the cyclic structure. Also, the PAEP/DDM resin exhibited excellent intrinsic flame retardant properties, including significantly reduced peak heat release rate (153.5 W·g −1 ) and high limit oxygen index (LOI) (34.7%), and a V-0 rating in the UL-94 test. Moreover, the PAEP/DDM resin exhibited a remarkably low dielectric constant of 2.25 at 10 6  Hz for telecommunication applications, which is much lower than the current epoxy resins with nanoporous inorganic modifiers. Therefore, the incorporation of pillar[5]arene is a fruitful pathway to expand the properties of epoxy resins and provides a new platform for decoration for various applications.