HEALING BEHAVIOR OF A DGEBA EPOXY CURED WITH A CYCLOALIPHATIC DIAMINE

2, catalyst/monomer inclusions that cause autonomous healing 3 or thermoset-thermoplast polymer composites 4 . The incorporation of healing agents in these materials has to satisfy two criteria for strength recovery at a crack interface; viz. molecular mobility of the healing agent towards a damage zone followed by a bonding mechanism that lends substantial adhesive strength at this interface. The research carried out has looked into how these requirements can be met by incorporating functionality into commercial thermosetting polymers and very little work has focused on understanding the possibility of strength recovery in a thermoset as a baseline system 5 . The focus of this report is to explain the significant crack-healing characteristics exhibited by commercial epoxy-amine thermosets prior to modification. This study is particularly relevant since the observed healing efficiencies are comparable to currently used healable thermosets and might shed insight into novel strategies to incorporate healing in multifunctional composite structures. Experimental Materials. Diglycidyl ether of bisphenol A epoxy resin (EPON 828, Miller Stephenson), 4,4’ methylene biscyclohexanamine (PACM, Air Products) and Tetrahydrofuran (THF, 99.9%, Sigma Aldrich) were used as obtained without further purification. The chemical structures of the monomers used are shown in Figure 1.