Effects of environmental degradation on near-fiber nanomechanical properties of carbon fiber epoxy composites

The fiber and matrix interphase is believed to control the fundamental load-transfer process and thereby bulk mechanical properties of composites. Carbon fiber reinforced composite properties have been qualitatively shown affected by moisture based degradation, however, quantitative characterization of the nanomechanical properties as a function of exposure time is still unknown. Here, quantitative measurement of the degraded epoxy matrix properties has been performed, taking advantage of the high scanning resolution of atomic force acoustic microscopy (AFAM). Composite samples were exposed to accelerated degradation and characterized using AFAM, showing a variation in elastic modulus of the matrix as a function of exposure.