Effect of core–shell rubber (CSR) nano-particles on mechanical properties and fracture toughness of an epoxy polymer

摘要: Abstract A DGEBA epoxy resin cured using dicyandiamide hardener, was modified by two types of CSR nano-particles over a range volume fractions from 0 vol.% to 38 vol.%. The size and microstructure particles were studied the measured diameters are 203 nm (with 16.9 nm shell thickness) 74.1 nm respectively. Addition nano increased glass transition temperature due interaction between matrix particles. ductility Poisson's ratio epoxy, but reduced Young's modulus tensile strength. modulus, strength well predicted theoretical models an effective fraction rubber. An optimum content found exist, when fracture energy 343 J/m2 for 2671 J/m2 30 vol.% particles, then started decline. main toughening mechanisms proved be debonding matrix, followed plastic voids growth, which accompanied shear bands yielding. Large-scale void growth discovered at subcritical tip double notch four points bending test (DN-4PB), values proportional damage zone crack DN-4PB. This is major mechanism, correlated with results modelling. model used predict toughness increment band yielding growth. analytical showed good agreement experimental data, further demonstrated proposed mechanism.