The fluoroalkyl‐modified polyester (PE‐Fn) was synthesized by the reaction of polyester resin (PE) and fluorinated isocyanate, and the structure of the synthesized product was characterized by proton nuclear magnetic resonance (1H‐NMR) and fluorine nuclear magnetic resonance (19F‐NMR). The water and oil wettability of the cured PE coatings with PE‐Fn as additives was investigated by contact angle meter. The results showed that the introduction of an extremely low concentration of PE‐Fn into PE led to the increase in contact angle of water and diiodomethane on cured PE coatings, and the decrease in the surface free energy. The X‐ray photoelectron spectroscopic (XPS) analysis showed that the F/C molar ratio in the outer few nanometers was significantly higher than that in the bulk, indicating that the fluoroalkyl groups in PE‐Fn had enriched on the coating surface. It was also found that longer fluoroalkyl groups and fluoroalkyl groups with CF3 at its end had the higher tendency to aggregate on the coating surface. The topological structures of the cured coatings were recorded by an atomic force microscope under tapping mode and the results revealed that there was a strong surface segregation of fluorinated species. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39812.

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Polyamide 6 (PA6) nanocomposites based on epoxy resin-modified montmorillonite (EP-MMT) were prepared by melt processing using a typical twin-screw extruder. X-ray diffraction combined with transmission electron microscopy was applied to elucidate the structure and morphology of PA6/EP-MMT nanocomposites, suggesting a nearly exfoliated structure in the nanocomposite with 2 wt % EP-MMT (PA6/2EP-MMT) and a partial exfoliated-partial intercalated structure in PA6/4 wt %EP-MMT nanocomposite (PA6/4EP-MMT). The thermogravimetric analysis under air atmosphere was conducted to characterize the thermal-oxidative degradation behavior of the material, and the result indicated that the presence of EP-MMT could inhibit the thermal-oxidative degradation of PA6 effectively. Accelerated heat aging in an air circulating oven at 150 C was applied to assess the thermal-oxidative stability of PA6 nanocomposites through investigation of reduced viscosity, tensile properties, and chemical structure at various time intervals.The results indicated that the incorporation of EP-MMT effectively enhanced the thermal-oxidative stability of PA6, resulting in the high retention of reduced viscosity and tensile strength, and the low ratio of terminal carboxyl group to amino group.