Addition of poly (ethylene-co-methacrylic acid) (EMAA) as self-healing agent to carbon-epoxy composites

Among several self-healing approaches to improve the durability of polymer-based materials during service, the addition of thermoplastics to a thermoset matrix has emerged as a promising self-healing alternative. In this study, poly (ethylene-co-methacrylic acid) (EMAA) was added to the mid-plane of carbon fiber-epoxy composite laminates to produce a self-healing system. Composite plates were manufactured with the addition of 5 wt%, 10 wt% and 15 wt% of EMAA as related to the matrix weight in the prepreg laminate. Interlaminar shear strength (ILSS) tests, dynamic mechanical analysis (DMA), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and field-emission gun scanning electron microscopy (FEG-SEM) were employed to evaluate the self-healing effect and composite properties before and after a healing cycle. Storage modulus was found to decrease with increasing content of EMAA in the laminate. Samples with EMAA showed complete recovery of interlaminar shear strength after healing.