Abstract: The microstructure of polyoxymethylene(POM)/polyurethane( PU)/ethylene-vinylacetate copolymer blends were analyzed by SEM, DSC and WAXD techniques,andtheir mechanical properties were measured.The results showed that the addition of PUcaused the decrease of Tm and crystallinity of blends,the increase of the crystallite size L₁₁₀ and the cell parameters of the blends,the decrease of the tensile strength and the appearanceof peak value in notched impact strength.Crystallite size L₁₁₀ between 10.86nm and 14.87nmled to modified POM with good balanced mechanical properties.

Key words: polyoxymethylene, polyurethane, blend, microstructure, mechanical property