Curing effects of single-wall carbon nanotube reinforcement on mechanical properties of filled epoxy adhesives

Enhancing epoxy adhesives using nanoscale fillers requires understanding processing-structure-property relationships as a function of nanoscale filler loading. In particular, the effects of adding nanoscale reinforcement to filled epoxies, such as those qualified for space applications, have yet to be characterized. In this effort, the addition of single-walled carbon nanotubes (SWNTs) to Hysol 9309.2 epoxy was investigated using a multi-scale mechanical characterization approach. Effects of SWNTs on the kinetics of epoxy curing were characterized and modeled using macromechanical dynamic mechanical analysis (DMA). Adhesion between SWNTs and microfiber reinforcement was identified with scanning electron microscope (SEM), and effects of SWNTs on mechanical properties of the filled epoxy were quantified using micromechanical tensile testing. Effects of SWNT reinforcement on mechanical behavior of the epoxy matrix were also characterized using nanomechanical characterization. This multi-scale mechanical characterization enabled the effects of SWNTs to be isolated from the epoxy and filler phases inherent in the adhesive.