The crystallization behavior of nylon 66/ nano-SiO2 composites

The nylon 66-based composites containing modified nano-SiO₂ (HMS) were prepared in a twin-screw extruder by melt compounding. The microstructures of nylon 66/ nano-SiO₂ composites were investigated by means of TEM and XRD, and the crystallization behavior was studied through Mo method based on DSC analysis. The results showed that the dispersion of HMS was uniform in nylon 66, which could be related to surface structure of HMS. It was found from the study of the crystallization behavior that modified nano-SiO₂ possessed a heterogeneous nucleation capability in nylon 66 matrix, and its addition could hinder the motion of nylon 66 molecular chain, lower the crystallization temperature, and prolong the crystallization time of nylon 66. In addition, the activation energies of neat nylon 66 and composites were also evaluated by the Kissinger method. The result showed that the activation energies of nylon 66/ nano-SiO₂ composites were higher than that of neat nylon 66.