Morphologies and viscoelastic behavior of high density polyethylene/nylon 6 (HDPE/PA6) blends compatibilized by maleic anhydride grafted high density polyethylene(HDPE-g-MAH) were studied through observation of scanning electron microscope(SEM) and dynamic rheological testing.It is found that HDPE-g-MAH can efficiently enhance the compatibility between PA6 and HDPE and improve the dispersion of PA6 and the interfacial state of phases due to in situ forming of graft copolymer (HDPE-g-PA6).Such improvement appears more obviously with the increasing of HDPE-g-MAH content when the concentration of HDPE-g-MAH is below 20 wt%.Hence
change of HDPE-g-PA6 amount also results in corresponding variations of linear viscoelastic behavior for the blends.The zero shear viscosity of blends increases with the addition of HDPE-g-MAH and approaches invariablenes with 20 wt% HDPE-g-MAH.At low frequency region the dependence of storage modulus on frequency for the blends tends to be weakened with the increase of HDPE-g-MAH concentration and begins to show “second plateau" with 10 wt% HDPE-g-MAH.These phenomena reflect macromolecularchains entanglement enhancement due to HDPE-g-PA6 forming.Both changes in morphologies and viscoelastic behavior for blends are ascribed to formation of HDPE-g-PA6.Compared with SEM observation
dynamic rheological testing gives much information about interface and interaction between macromolecular-chains.It is suggested that structure evolution with increase of HDPE-g-MAH content for HDPE/PA6 blends can be characterized preferably by using dynamic rheological measurements.