Abstract
Recently the term of interphase is recognized and mainly used instead of the term of interface because the interphase should be considered not only for two dimensional boundary plane between fiber and matrix but also the three dimensional volume containing the region of matrix resin modified by silane coupling agent. In this paper, the functional interphase as a new concept of composites interphase was suggested. It is expected that the functional interphase could improve the performance of composites and add the farther function such as strengthening, toughening and so on. In this study the static tensile properties and initial failure behavior of glass woven fabric/epoxy composite plate with flexible interphase were investigated. The modulus and the strength were kept the same in any thickness of flexible interphase. The thickness of flexible interphase was well controlled by changing the concentration of flexible resin to the chemical solvent of acetone. The first and second Knee Points were identified by least squires method on tensile stress-strain curves. The Knee Point stress was maximized at 1.0 wt.% and decreased with increase in concentration. Accordingly the optimum concentration, namely optimum thickness exists to improve the initial failing stress.
