AbstractThis article reports some morphological, tribological, and mechanical data on polyamide-11(PA11)/halloysite nanotube (HNT) nanocomposites prepared by melt-compounding. HNTs extracted from the Djebel Debbagh deposit in Algeria were incorporated into the polymer at 1, 3, and 5 wt%. For comparison, commercial HNTs were also used under the same processing conditions. Scanning electron microscopy showed that both HNTs were homogeneously dispersed in the PA11 matrix, despite the presence of few aggregates, in particular at higher filler contents. The tribological properties were significantly improved, resulting in a decrease in the friction coefficient and the wear rate characteristics due to the lubricating effect of HNTs. This is consistent with optical profilometry data, which evidenced the impact of both types of HNTs on the surface topography of the nanocomposite samples, in which the main wear process was plastic deformation. Furthermore, Young’s modulus and tensile strength were observed to increase with the filler content, but to the detriment of elongation at break and impact strength. Regarding the whole data, the raw Algerian halloysite led to interesting results in PA11 nanocomposites, thus revealing its potential in polymer engineering nanotechnology.

The degradation of uncompatibilized and compatibilized PP/PA‐6 (70/30 wt %) with PP‐g‐MA under accelerated UV light was investigated using Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, melt flow index (MFI) tester, tensile test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). FTIR analysis of the structure of the compatibilized and uncompatibilized blends after exposure to UV light showed the formation of photoproducts corresponding to both components. The MFI and mechanical results obtained revealed that photooxidation started primarily in PA‐6 rather than PP. In addition, the uncompatibilized blends exhibited a higher degradation rate compared to neat polymers for long exposure time, and the addition of PP‐g‐MA increased slightly their ageing rate in accordance with TGA data. Further, DSC analysis showed an increase in the crystallinity index and a decrease in the melting temperature of PP and PA‐6 after UV exposure either as neat polymers or as blend components. SEM micrographs of the cryo‐fractured surfaces of the samples illustrated the formation of cracks and fractures after UV irradiation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41722.

Summary: The present paper deals with the effects of natural weathering on the properties of poly(propylene)/polyamide‐6 blends (70/30 wt %) without and with PP‐g‐MA used as the compatibilizer at various content ratios (2, 4 and 6 wt%). The resulted changes in the chemical structure, morphology and mechanical properties of the different blends were analyzed by Fourier transform infrared (FT‐IR) spectroscopy, scanning electron microscopy (SEM), and tensile tests. After one year of outdoor exposure, no important changes in the chemical structure are observed by FT‐IR spectroscopy for both virgin and compatibilized blends. SEM analysis revealed the effectiveness of PP‐g‐MA to improve the compatibility of PP/PA‐6 blends. However, the weathering effect on the morphology of both virgin and compatibilized blends resulted in the formation of voids and cracks on the fracture surfaces, while the ultimate tensile properties decreased considerably. The overall results indicated clearly that the presence of PP‐g‐MA compatibilizer in PP/PA‐6 blends had no influence on the photo‐oxidation process.