Mechanical performances of hygrothermally conditioned CNT/epoxy composites using seawater

Hygrothermic aging of epoxy and carbon nanotube (CNT)/epoxy composites (0.5, 0.75, and 1 wt.%) was studied for their application suitability in seawater environments. The specimens were emerged in seawater and kept at constant temperature of 30 degrees C for a maximum duration of 180 days. The specimens were periodically weighed for water absorption study and tested for mechanical as well as thermal properties. All aged samples were showing some amount of degradation owing to their moisture-absorption rates. CNT composites absorbed less moisture than pure epoxy because of the presence of nanofillers. C-0.75 was found to be hygrothermally more stable reflecting minimum reduction in flexural properties and glass transition temperature value, which was due to least moisture/water absorption. Deterioration of properties was significant in C-1, though it was better than pure epoxy. Fractographic analysis by scanning electron microscopy (SEM) revealed interfacial debonding as the dominant failure mechanism, resulting in pull out of nanotubes.