Ultrahigh molecular mass polyethylene (UHMWPE) and statistical copolymer of ethylene and 1-hexene (PEH) were used to prepare UHMWPE/PEH blends with relatively low UHMWPE concentrations. UHMWPE forms network structure in the blends with UHMWPE concentrations above a critical value of c=1wt%. The influence of the formed UHMWPE network on the interfacial diffusion behaviors of multilayer UHMWPE/PEH blends was investigated by applying small oscillatory shear rheology. The interfacial diffusion coefficients of multilayer UHMWPE/PEH blends were obtained from the rheological data. It is found that the diffusion coefficients are time-dependent and two diffusion regions are distinct before the diffusion reaches the plateaus according to the changes of diffusion exponent n in the relation of D-t n

which implies an approximate Fickian diffusion behavior in region Ⅰ (c 1.0wt%) and an obvious deviation from the Fickian diffusion behavior in region Ⅱ (c1.0wt%). With the formation of UHMWPE network in the UHMWPE/PEH blends

deviation from the Fickian behavior for diffusion of multilayer UHMWPE/PEH blends becomes significant. The above results help facilitate the industrial processing of multilayer polyolefins

which is related to the interfacial diffusion.