Rheology, morphology and mechanical properties of immiscible PA6/LDPE blends filled with silica nanoparticles

A series of Nylon 6/ Low-density polyethylene (PA6/LDPE) (90/10 w/w) and (10/90 w/w) containing 0.25,0.5, 0.75 and 1% phr modified Silica nanoparticles were melt processed and the effect of nanoparticles on morphological properties was investigated. SEM images revealed a decrease in the average number of domain diameter (Dn) of LDPE phase for Silica nanoparticles amount up to 0.5% phr in the PA6-rich blend, whereas, an increase in Dn of PA6 was observed up to 0.75 phr silica nanoparticles which led us to conclude the preferential location of nanoparticles in PA6. Rheological relaxation time of the blends also suggests that the morphology transition can be related to the changes in dynamic asymmetry between PA6-rich and LDPErich phase. Improvement in storage modulus measured by DMTA was relatively more in PA6-rich blend than LDPE-rich blend which is attributed to the reinforcing effect of nanoparticles arising from the interaction with the PA6 chains.