Effect of particle sizes of zinc oxide on mechanical, thermal and morphological properties of polyoxymethylene/zinc oxide nanocomposites

The effects of particle size of zinc oxide (ZnO) on mechanical, thermal and morphological properties of pure polyoxymethylene (POM) and POM/ZnO nanocomposites were investigated. POM/ZnO nanocomposites with varying concentration of ZnO were prepared by a melt mixing technique in a twin screw extruder. The dispersion of ZnO particles in POM composites was studied by scanning electron microscopy (SEM). The agglomeration of ZnO71 (71 nm) particles in the polymer matrix increased with increasing ZnO content. The POM/ZnO71 and POM/ZnO250 (250 nm) nanocomposites showed decrease in tensile strength with increasing filler content. Young's modulus and stress at break of POM/ZnO71 and POM/ZnO250 nanocomposites increased with increasing filler contents. The impact strength of POM nanocomposites increased up to a ZnO content of 1.0 wt%. However, the POM/ZnO71 nanocomposites had higher mechanical properties than the POM/ZnO250 nanocomposites. The degradation temperature of POM/ZnO71 nanocomposites was higher than that of POM/ZnO250 nanocomposites. (C) 2008 Elsevier Ltd. All rights reserved.