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Two master-batches, polyamide 66 (PA66)/organo-montmorillonite (OMMT) and polyamide 6 (PA6)/OMMT, prepared by melt compounding with methyl methacrylate (MMA) as co-intercalation agent, have been used to prepare nearly exfoliated PA66/montmorillonite (MMT) nanocomposites. The resulting nanocomposites are compared in view of their morphology and properties. Nano-scale dispersion of OMMT is realized in both types of nanocomposites, as revealed by XRD, TEM and Molau tests. PA66/MMT nanocomposites having superior mechanical properties and heat distortion temperature (HDT) can be obtained from either PA66/OMMT or PA6/OMMT master-batch. Those from PA6/OMMT have lower tensile and flexural properties, and HDT than those from PA66/OMMT due to the presence of less stiff and less thermal resistant PA6. The crystallization behavior and crystal structure of the matrix in both types of PA66/MMT nanocomposites are also investigated by DSC and WAXD.

Dynamic mechanical properties and morphology of a thermotropic liquid crystalline polymer poly(HBA/PET 80/20) and polyamide 66 (PA66) blends were studied. Rectangular samples were obtained by injection molding at 280 (C, which is above the nematic transition temperature of the LCP. Two parameters were investigated: LCP content varying from 0 to 100 wt% and the mould cavity thickness ranging from 1 to 4 mm. At a given mould thickness, the storage modulus (E') increased with increasing LCP content, which is due to an enhancement in the concentration of LCP fibers. The tan(peak was broad for the blends and the peak value decreased with increasing LCP content, resulting from the inclusion of rod-like rigid molecules. For pure LCP, E' increased with decreasing mould thickness in the temperature range studied (0-200(C). It was ascertained by XRD and SEM methods that better LCP fibrillation in the skin region could be achieved by increasing the shear rate through the reduction of the mould cavity thickness.