effect of nanosilica contents on molecular packing of epoxy resin

Epoxy resins are one of the most prominent resins in the world# many factors affect the mechanical properties of this family of polymers, but the effects of some factors including molecular packing on the mechanical properties are less investigated# the important factor affecting molecular packing and mechanical properties is the curing agent chemical structure# three different curing agents including meta-phenylene diamine (m-pda), ortho-phenylene diamine (o-pda) and 2,4-diamino toluene (2,4-dat) were used for curing the epoxy nanocomposites and the effect of nano silica contents was studied on the molecular packing# the melting method was used for curing of epoxy resin# first, the curing agent was melted and then the epoxy resin was added# to study the effect of nanosilica contents, three different nanosilica contents including 2, 4 and 6%wt were used# the molecular packing was studied by x-ray diffraction technique# also, the density measurements of cured epoxy resins was carried out using the archimedes method and finally, the effect of molecular packing on the mechanical properties was investigated by tensile test# the obtained results from xrd and tensile test measurements showed that there is a direct relationship between molecular packing and mechanical propretis# by increasing the nanosilica percentage in the nanocomposite, the molecular packing and also molecular packing distribution was increased# the highest molecular packing was 4#59å for o-pda curing agent with 6 wt% nanosilica content# the results of tensile tests of nanocomposites showed an increase in mechanical properties of nanocomposites up to 4% nanosilica content as function of molecular packing#