Crystallization and thermal behavior of polyamide 6/ poly(ethylene-co-1-butene)-graft-maleic anhydride/organoclay nanocomposites

Nanocomposites based on polyamide 6 (PA6) and poly(ethylene-co-1-butene)-graft-maleic anhydride (EB-g-MAH) blends have been prepared via melt mixing. The effect of blend ratio and organoclay concentration on the crystallization behavior and the thermal properties of specimens were studied. Three types of organoclays (Cloisite 30B, Cloisite 15A and Cloisite 20A) were employed to assess the importance of the nanoclay surface polarity and gallery distance. The crystallization behavior was investigated using differential scanning calorimetry (DSC) and wide angle X-ray diffraction spectroscopy (WAXD). The strong interactions between amine end groups of PA6 and maleic anhydride groups of EB-g-MAH led to complete inhibition of EB-g-MAH crystallization according to the DSC results. A transformation from α form PA6 to the γ form crystals for PA6, induced by both organoclays and EB-g-MAH was confirmed by WAXD and DSC. The thermal properties of the nanocomposites were investigated by DSC and compared with that of neat blends. Moreover, transmission electron microscopy (TEM) was conducted and indicated that the organoclays mainly present in the PA6 matrix and rarely distribute in the EB-g-MAH phase in the case of low polarity organoclays. It was also observed that the organoclay with the most affinity to PA6 (Cloisite 30B) had the largest effect on the thermal and crystallization behavior of this phase

Keywords:

Polyamide 6 , Nanocomposites , Crystallization , Thermal behavior , Morphology