Self-healing epoxy networks based on cyclodextrin-adamantane host-guest interactions

An aminated beta-cyclodextrin (NCD) with an amine substitution degree of 16.4 was prepared through the thiol-ene reaction of allylated beta-cyclodextrin and cysteamine hydrochloride. The thermal curing reactions of sorbitol polyglycidyl ether (SPE) with NCD, Jeffamine (R) ED-600 (JA, an aliphatic polyether amine), and adamantylamine (NAD) with a feed epoxy/NH2 ratio of 1:1 and feed NH2 molar ratios of NCD/JA/NAD = 1/1/1 and 1/2/1 produced epoxy-amine networks. The FT-IR and gel fraction measurements for the cured products revealed that polymer networks were formed by the reaction of epoxy and amino groups. The cured product with a higher JA content showed lower glass transition temperature (T-g), tensile strength, and tensile modulus results than those of the cured product with a lower JA content. Compared with the product with lower JA, the product with higher JA exhibited self-healing properties upon treatment at 60 degrees C. The self-healing driven by the NCD/NAD host-guest interaction was demonstrated as the self-healed sample returned to its original state after immersion in an ethanol solution of NAD. Moreover, the corresponding SPE/NCD/JA and SPE/JA/NAD cured products did not exhibit self-healing capacity.