ANELASTIC DEFORMATION OF A THERMOPLASTIC-MATRIX FIBER-COMPOSITE AT ELEVATED-TEMPERATURE .3. STRUCTURE AND THERMOMECHANICAL PROPERTIES OF AS4 PACM-12 COMPOSITE/

Structural characterization of AS4-graphite fiber/PACM-12 sectional si gn matrix composites was conducted using Differential Scanning Calorim etry (DSC) and Wide-Angle X-Ray Diffraction (WAXD) analyses. The DSC r esults indicate the significant effect of processing variables on the morphology, microstructure and crystallinity of the fiber reinforced s emicrystalline thermoplastic matrix prepreg and unidirectional laminat es. From WAXD results the crystallinity was determined. Time-temperatu re dependent thermomechanical properties of the laminates were evaluat ed using dynamic mechanical spectroscopy and creep compliance measurem ents. Dynamic mechanical spectra revealed the matrix-dominated time-te mperature dependent behavior of the laminate under torsional loading. Elevated temperature creep compliance in the longitudinal direction sh owed time-temperature independent behavior whereas transverse creep de formation was found to be significantly time-temperature-stress depend ent.