Role of intrinsic flaws upon flexural behaviour of a thermoplastic modified epoxy resin

摘要: Abstract A bisphenol A-based epoxy resin (DGEBA) was modified with 15 weight percent polysulphone (PSU) and thermally cured using 4-4′diaminodiphenylsulphone (DDS). Starting from a homogeneous DGEBA/DDS/PSU mixture, the system developed two-phase morphology upon network formation. Dynamic mechanical analysis (DMA), transmission optical microscopy (TOM) scanning electron (SEM) studies showed that co-continuous consisting of two distinct domains. One domains an rich matrix containing PSU particles while other consisted dispersion within phase. Flexural strength distributions unmodified thermoplastic were obtained by testing materials in three-point bending according to ASTM D790 protocol. The flexural behaviour not improved presence thermoplastic. In addition, displayed higher data scatter compared neat resin. fracture mechanism resins demonstrated be sensitive intrinsic flaw distribution. two-parameter Weibull model, which used analyse experimental data, gave good representation loads distribution regression coefficients 0.99.