Preparation And Characterization Of Nylon-6/Montmorillonite Nanocomposites

In this paper, the processing conditions of preparing Nylon-6 / clay nanocomposites by Water-Assisted Melt Compounding method were studied, and the structure and properties of the nanocomposites were characterized in detail by means of XRD, TEM, and DSC etc.DSC and XRD experimental results indicated that the crystal form of polyamide-6 in nanocomposites was mainlyγcrystal form. It has been found that the presence of montmorillonite influences the crystal form of polyamide-6 in nanocomposites with increasing of montmorillonite content in nanocomposites, the content ofγcrystal form increased. The XRD patterns and the TEM images of the nanocomposites showed that the montmorillonite layers were exfoliated into nanometer size and dispersed uniformly in the polyamide-6 matrix.The results of XRD and DSC show that the nanocomposites have a crystal structure and crystallization behavior different from that of pure PA6. DSC rising scanning curves show that the nanocomposites have melt double-peak, it was explained that the addition of montmorillonite promoteγcrystal form of PA6 formed. While cooling scanning curves show, with the increment of the montmorillonite content in the nanocomposites, that lost the supercooling degrees, narrowed the width of the crystalline peak, increased the crystalline degrees, decreased crystallization rate parameter K, reduced the crystallization activation energy and half crystallization time of nanocomposites than that of pure PA6. According to the experimental results we conclude that montmorillonite play the role of iso-phase nucleation in the PA6 matrix, thus enhanced the crystallization rate of PA6 obviously.The results indicated, when compared to the pure PA, that mechanical property testing results indicated that the properties of nanocomposites are superior to those of PA6. This is due to nanoscale effect and the strong interaction between PA6 matrix and montmorillonite interface as revealing in XRD and TEM. The rheological behaviors of nanocomposites and pure PA6 were studied. The results showed that the nanocomposites exhibits similar shear thinning behavior as pure PA6,belonged to pseudoplastic and non-Newtonian fluid, the non-Newtonian index was less than the pure PA6. The apparent viscosity of nanocomposites was lower than PA6, and gradually decreases with increase of clay content, temperature and shear rate.