Mechanical Characterization of Woven Carbon Fiber Composites with Poly(methyl methacrylate)-modified expoxy Matices

摘要

The influence of hte modification of epoxy matrices with poly(methyl methacrylate)(PMMA)on the fracture behavior of composite laminates based on woven carbon fibers has ben investigated.Three-point flexural,short beam shear (SBS)and end-not ched flexural tests (ENF)have been carried out.Microstructural features have been investigated by atomic force microscopy (AFM)and scanning electron misroscopy (SEM).Dynamic mechanical thermal analyiss of the different epoxy matrices and their correspondign composites shows the power of this technique for microstructural studies.Fracture behavior is compared with that shown by similar bifunctional (DGEBA)exoxy matrix composites.In spite of hte tow-phase structure obtained in tetrafunctinal (TGDDM)epoxy matix-based systems for all PMMA contents,only a small improvement in fracture toghness and interlaminar shear strength properties was obtained.In contrast,for DGEBA bulk matrices and composites,a higher enhancement of fracture toughness was botained,as a consequence of the lower crosslink densities of bifunctional matrices.