Abstract: Polyoxymethylene/reactable nanoSiO2 (RNS) composites were prepared by melting blending. The nonisothermal crystallization behavior of POM and its composites were studied with differential scanning calorimetry (DSC) and the effect of nanoSiO2 was explored. Nonisothermal crystallization kinetics was described using Jeziorny and Mo methods. The RNS played a role of heterogeneous nucleation in the POM matrix, however, it resisted the diffusion of the segments. The net result was a lower crystallization rate  and longer crystallization halftime. The Avrami exponent n decreased, which indicated that RNS had changed the growth mechanism of POM. Dynamic mechanical analysis (DMA) indicated some improvements in the storage modulus with the addition of RNS. The tanδ peaks signifying the glasstransition temperature of POM shift to higher temperature, implying some strong interaction between nanoSiO2 and POM.

Key words: polyoxymethylene, nano silicon dioxide, non-isothermal crystallization, dynamic mechanical analysis