关键词: 聚甲醛, 纳米二氧化硅, 力学性能, 热性能, 结晶行为

Abstract: Polyoxymethylene (POM)-based nanocomposites with amino-group-modified nano-silica (RNS) and methyl-group-modified nanosilica (DNS) particles were prepared through melt compounding by a twin-screw extruder, and their mechanical and thermal properties, crystallization behaviors of the resulted nanocomposites were investigated. The results indicated that the tensile strength and notched impact strength of the two nanocomposites could be enhanced at low contents of RNS and DNS, and they could be further improved with increasing contents of the two nanofillers until the maximum values were achieved. Nevertheless, the Young’s modulus presented a continual increase with increasing the nanofillers content. The incorporation of RNS improved the thermal decomposition temperature of POM significantly, whereas the introduction of DNS showed little influence on the maximum decomposition temperature of POM. Both RNS and DNS demonstrated a strong heterogeneous nucleation capability. The presence of these two nanofillers increased the crystallization temperature but reduced the crystal size of POM.

Key words: polyoxymethylene, nano-silica, mechanical property, themal property, crystallization behavior