The Al–AlO–MgO composites with added aluminum contents of approximately 0wt%, 5wt%, and 10wt%, named as M, M, and M, respectively, were prepared at 1700°C for 5 h under a flowing Natmosphere using the reaction ...The Al–AlO–MgO composites with added aluminum contents of approximately 0wt%, 5wt%, and 10wt%, named as M, M, and M, respectively, were prepared at 1700°C for 5 h under a flowing Natmosphere using the reaction sintering method. After sintering, the Al–AlO–MgO composites were characterized and analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results show that specimen Mwas composed of MgO and MgAlO. Compared with specimen M, specimens Mand Mpossessed MgAlON, and its production increased with increasing aluminum addition. Under an Natmosphere, MgO, AlO, and Al in the matrix of specimens Mand Mreacted to form MgAlON and AlN-polytypoids, which combined the particles and the matrix together and imparted the Al–AlO–MgO composites with a dense structure. The mechanism of MgAlON synthesis is described as follows. Under an Natmosphere, the partial pressure of oxygen is quite low; thus, when the Al–AlO–MgO composites were soaked at 580°C for an extended period, aluminum metal was transformed into AlN. With increasing temperature, AlOdiffused into AlN crystal lattices and formed AlN-polytypoids; however, MgO reacted with AlOto form MgAlO. When the temperature was greater than(1640 ± 10)°C, AlN diffused into AlOand formed spinel-structured AlON. In situ MgAlON was acquired through a solid-solution reaction between AlON and Mg AlOat high temperatures because of their similar spinel structures.展开更多
Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments.Herein,polyurethane was composited with polyaniline and nanosilica based on in sit...Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments.Herein,polyurethane was composited with polyaniline and nanosilica based on in situ synthesis of polymer and physical mixing of these fillers to reach desired antistatic and mechanical properties.Chemical,morphological and thermal properties of the polyurethane/polyaniline/nanosilica composites were studied.The electrical resistivity of the composite decreased from 1.1×10^(6)MΩto 7.6×10^(4)MΩas a result of the addition of 4%polyaniline.The tensile strength and elongation at break of the polyurethane composites improved by nearly 300%and100%,respectively,when compared with those of the neat polyurethane.The electronic resistance of PU/PANI/NS ternary is low enough for its antistatic property and decreases with the increase of the added nanosilica,which is unexpectedly and rather significant.Our results would shed light on the development of antistatic PU with excellent mechanical performance.展开更多
文摘The Al–AlO–MgO composites with added aluminum contents of approximately 0wt%, 5wt%, and 10wt%, named as M, M, and M, respectively, were prepared at 1700°C for 5 h under a flowing Natmosphere using the reaction sintering method. After sintering, the Al–AlO–MgO composites were characterized and analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results show that specimen Mwas composed of MgO and MgAlO. Compared with specimen M, specimens Mand Mpossessed MgAlON, and its production increased with increasing aluminum addition. Under an Natmosphere, MgO, AlO, and Al in the matrix of specimens Mand Mreacted to form MgAlON and AlN-polytypoids, which combined the particles and the matrix together and imparted the Al–AlO–MgO composites with a dense structure. The mechanism of MgAlON synthesis is described as follows. Under an Natmosphere, the partial pressure of oxygen is quite low; thus, when the Al–AlO–MgO composites were soaked at 580°C for an extended period, aluminum metal was transformed into AlN. With increasing temperature, AlOdiffused into AlN crystal lattices and formed AlN-polytypoids; however, MgO reacted with AlOto form MgAlO. When the temperature was greater than(1640 ± 10)°C, AlN diffused into AlOand formed spinel-structured AlON. In situ MgAlON was acquired through a solid-solution reaction between AlON and Mg AlOat high temperatures because of their similar spinel structures.
基金financially supported by Natural Science Advance Research Foundation of Shaanxi University of Science and Technology(No.2020XSGG-07)the National Natural Science Foundation of China(No.31570578)Key Research and Development Program of Shaanxi(No.2022GY-278)。
文摘Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments.Herein,polyurethane was composited with polyaniline and nanosilica based on in situ synthesis of polymer and physical mixing of these fillers to reach desired antistatic and mechanical properties.Chemical,morphological and thermal properties of the polyurethane/polyaniline/nanosilica composites were studied.The electrical resistivity of the composite decreased from 1.1×10^(6)MΩto 7.6×10^(4)MΩas a result of the addition of 4%polyaniline.The tensile strength and elongation at break of the polyurethane composites improved by nearly 300%and100%,respectively,when compared with those of the neat polyurethane.The electronic resistance of PU/PANI/NS ternary is low enough for its antistatic property and decreases with the increase of the added nanosilica,which is unexpectedly and rather significant.Our results would shed light on the development of antistatic PU with excellent mechanical performance.
