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Shouguang, China

Li J.,Shanghai Second Polytechnic University | Li X.Z.,English Group
Materials Technology | Year: 2010

Blending polytetrafluorothylene (PTFE) to polyamide 6 (PA6) with and without maleic anhydride grafted PTFE was produced in a corotating twin screw extruder, where PTFE acts as the polymer matrix and PA6 as the dispersed phase. The effect of maleic anhydride grafted PTFE on the tensile properties of PTFE/PA6 polymer blends is studied. Results show that the structural stability and morphology of the blends were greatly improved by PTFE-g-PA6 grafted copolymers, which were formed by the in situ reaction of anhydride groups with the amino end groups of PA6 during reactive extrusion forming an imidic linkage. The presence of PTFE-g-PA6 in the PTFE continuous phase improves the interfacial adhesion, as a result of the creation of an interphase that was formed by the interaction between the formed PTFE-g-PA6 copolymer in situ and both phases. © 2010 W. S. Maney & Son Ltd. Source


Li J.,Shanghai Institute of Technology | Li X.Z.,Shanghai Institute of Technology | Li X.Z.,English Group
Bulletin of Materials Science | Year: 2011

Thin films deposited on the phosphonate 3-aminopropyltriethoxysilane (APTES) self-assembled monolayer (SAM) were prepared on the hydroxylated silicon substrate by a self-assembling process from specially formulated solution. Chemical compositions of the films and chemical state of the elements were detected by X-ray photoelectron spectrometry (XPS). The thickness of the films was determined with an ellipsometer, while the morphologies and nanotribological properties of the samples were analyzed by means of atomic force microscopy (AFM). As the results, the target film was obtained and reaction might have taken place between the thin films and the silicon substrate. It was also found that the thin films showed the lowest friction and adhesion followed by APTESSAM and phosphorylated APTES-SAM, whereas silicon substrate showed high friction and adhesion. Microscale scratch/wear studies clearly showed that thin films were much more scratch/wear-resistant than the other samples. The superior friction reduction and scratch/wear resistance of thin films may be attributed to low work of adhesion of nonpolar terminal groups and the strong bonding strength between the films and the substrate. © Indian Academy of Sciences. Source


Nie W.Z.,Shanghai Institute of Technology | Li J.,Shanghai Second Polytechnic University | Zhang Y.F.,English Group
Plastics, Rubber and Composites | Year: 2010

In this study, acrylonitrile butadiene styrene (ABS) terpolymer was reinforced with HNO3 treated short carbon fibres (CFs). The effects of fibre weight fraction on the tensile properties of the composites were examined. Increasing the fibre weight fraction in the ABS matrix from 10 to 30 wt-% resulted in improved tensile strength and tensile modulus. To obtain a strong interaction at the interface, polyamide 6 (PA6) at varying concentrations was introduced into the ABS/ 10 wt-% CF composite. The incorporation and increasing amount of PA6 in the composites increased tensile properties of the ABS/PA6/CF systems due to the improved adhesion at the interface, which was confirmed by the ratio of tensile strength as an adhesion parameter. These results were also supported by scanning electron micrographs of the ABS/PA6/CF composites, which exhibited an improved adhesion between the CFs and the ABS/PA6 matrix. © Institute of Materials, Minerals and Mining 2010. Source


Li J.,Shanghai Second Polytechnic University | Zhang Y.F.,English Group
Journal of Reinforced Plastics and Composites | Year: 2010

In this study acrylonitrile-butadiene-styrene (ABS) terpolymer was reinforced with HNO3-treated short carbon fibers (HCFs). The effects of HCF concentration on the tensile properties of the composites were examined. Increasing the HCF concentration in the ABS matrix from 10 to 30 wt% resulted in improved tensile strength and tensile modulus. To obtain a strong interaction at the interface, polyamide-6 (PA6) at varying concentrations was introduced into the ABS/10 wt% SCF composite. The incorporation and increasing amount of PA6 in the composites increased tensile properties of the ABS/PA6/HCF systems due to the improved adhesion at the interface, which was confirmed by the ratio of tensile strength as an adhesion parameter. These results were also supported by scanning electron micrographs of the ABS/PA6/HCF composites, which exhibited an improved adhesion between the SCFs and the ABS/PA6 matrix. © 2010 The Author(s). Source


Nie W.Z.,Shanghai Institute of Technology | Li X.Z.,English Group | Sun F.F.,English Group
Journal of Materials Engineering and Performance | Year: 2010

The quality of interfacial interaction is dictated by the surface chemistry of the carbon fibers and the composition of the matrix. The composition of polystyrene was modified by the addition of maleic anhydride-grafted polystyrene (MAH-g-polystyrene). The surface properties of various matrix formulations were characterized by contact angle measurements. Carbon fibers were modified by nitric acid oxidation. The surface composition of the carbon fibers was characterized. The interaction between modified polystyrene and the carbon fibers was studied by single-fiber pull-out tests. The best adhesion behavior was achieved between polystyrene-containing grafted MAH and nitric acid-oxidized carbon fibers. The addition of MAH-g-polystyrene to the unmodified polystyrene caused the interfacial shear strength to increase. The apparent interfacial shear strength of this fiber-matrix combination allowed for the utilization of 100% of the yield tensile strength of polystyrene. © 2010 ASM International. Source

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