The effect of ambient moisture and temperature conditions on the mechanical properties of glass fiber/carbon fiber/nylon 6 sandwich hybrid composites consisting of skin‐core morphologies

Abstract

AbstractThe concept of skin‐core (SC) morphology was used to make sandwich hybrid composites in which the skin and core were composed of different fibers in the same matrix. The sandwich blends comprising glass skin with carbon core and vice versa were compared with those of the hybrid composite, while the respective carbon (CF) and glass fiber (GF) composites served as points of reference. The composites were compounded and fabricated into injection molded tensile specimens and 3‐mm thick plaques. The effect of ambient temperature and moisture was studied. The fracture mechanical characterization of the various materials was done by using notched compact tension (CT) specimens. Tensile properties were also used to characterize the composites. Morphogical studies based on scanning electron microscopy and light microscopy were used to elucidate fracture characteristics. Deterioration of properties was noticed under hot and humid conditions. Synergism in flexural properties was observed in the CF/GF/PA hybrid composite. The mechanical properties of the CF/GF/PA hybrid are closer to those of CF/PA, suggesting a cost advantage by substituting half of the carbon fibers with glass fibers. Dynamic mechanical analysis results revealed that synergism in Tg is attained by blending or sandwiching glass and carbon fibers. Morphological studies reaffirmed the skin‐core morphology of the composites. POLYM. COMPOS., 26:52–59, 2005. © 2004 Society of Plastics Engineers.