The effects of injection temperature on the dispersion phase and mechanical properties of polyoxymethylene／thermoplastic polyurethane elaster(POM／TPU)blends were investigated．The experimental results shewed that the notched impact strength of POM／TPU blends was greatly influenced by injection temperatures

and the highest value

19．1 kJ／m2

appeared at 195℃

two times as high as the value obtained at 175℃．Because the viscosity ratio of POM to TPU changed with temperature

and reached 1 at around 195℃

and TPU formed strips—like structure in POM matrix along with the flow direction of the melt during injection

which could effectively absorb impact energy

prevent growth of crazes and formation of cracks．With increase of injection temperature

the average particle size of TPU decreased

and the particle size distribution became narrower．It is an effective way to toughen POM by adjusting the viscosity ratio of the dispersion phase and the matrix and controlling the morphology of the dispersion phase．