Thermal stability, crystallization and mechanical properties of nylon11/montmorillonite nanocomposites

摘要

Nylon 11 nanocomposites with different montmorillonite loadings were successfully prepared by melt compounding. XRD and TEM show the exfoliated nanocomposites are formed at low montmorillonite concentration (less than 2 wt%) and the intercalated nanocomposites are obtained at higher montmorillonite contents. TGA shows that the thermal stability of the nanocomposites is improved by 27 °C when the montmorillonite content is only 2wt%. At the same time, The crystallization behavior of nylon11/montmorillonite nanocomposites has been studied by means of XRD, DSC.The Avrami equation described well the isothermal crystallization behavior of nylon11 and nylon11/montmorillonite nanocomposites. The results showed that the montmorillonite acted as the nucleating agent and facilitated the crystal growth rate of nylon 11 matrix. The incorporation of montmorillonite did not change the crystal morphology of nylon 11 but increased the crystallization temperature and decreased the crystallization activation energy, which lead to a easy crystallization of nylon11. Mechanical testing shows that the Izod impact strength of all nanocomposites are higher than that of the neat nylon 11, but the tensile strength of the nanocomposites decrease at low nanofiller concentrations (less than 8wt%) and then increased, when the montmorillonite content is 10wt% ,the tensile strength of the nanocomposite is 5% improved than neat nylon 11. This is may be due to the strong interaction between the nylon 11 matrix and the montmorillonite interface.