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21.
Synthesis and characterization of waterborne and phosphorus-containing flame retardant polyurethane coatings 总被引:2,自引:0,他引:2
Funda ?elebi Leyla Aras Güng?r Gündüz Idris M. Akhmedov 《Journal of Coatings Technology》2003,75(944):65-71
Phosphorus-containing flame retardant water-dispersed polyurethane coatings were produced by incorporating different amounts
of a phosphorus compound onto the polyurethane main chain. The novel phosphorus containing compound (phosphorus phenyl dihydroxy)
was synthesized in three steps using benzaldehyde, pentaerythritol, phenyl phosphonic dichloride, and acetic acid.
The addition of phosphorus phenyl dihydroxy to the main chain of polyurethane, in which NCO/OH ratio was kept constant at
1.5 and the amount of dimethylolpropionic acid (DMPA) at 3.5 wt%, increased the hardness and abrasion resistance, but only
slightly decreased the gloss values of the polyurethane paints. All the samples showed superior impact resistance and flexibility.
Moreover, increasing the phosphorus content increased the char yield, and the maximum fire retardancy was reached at 1.5%
P content with a limiting oxygen index (LOI) value of 29.
Kimya B?lümü, 06531 Ankara, Turkey. 相似文献
22.
Lalchand A Patil Dinesh N Suryawanshi Idris G Pathan Dhanashri G Patil 《Bulletin of Materials Science》2014,37(3):425-432
Nanostructured pure and Pt-doped TiO2 thin films were prepared by chemical spray pyrolysis technique. Aqueous solution of TiCl3·6H2O (0·01 M) was chosen as the starting solution for the preparation of pure TiO2 thin film. Aqueous solutions of PtCl6·6H2O (0·01 M) and TiCl3·6H2O (0·01 M) were mixed in volume % of 1 : 99, 2·5 : 97·5 and 5 : 95 respectively to obtain Pt-doped TiO2 thin films. The solutions were sprayed onto quartz substrate heated at 350 °C temperature to obtain the films. These thin films were fired for one hour at 550 °C. The sensing performance of these films was tested for various gases such as LPG, H2, CO2, ethanol, NH3 and Cl2 (1000 ppm). The Pt-doped TiO2 (1 : 99) was observed to be most sensitive (572) to H2 at 400 °C with high selectivity against other gases. Its response time was short (10 s) and recovery was also fast (14 s). To understand the reasons behind the gas-sensing performance of the films, their structural and microstructral properties were studied using X-ray diffraction and electron microscopy (FE–SEM and TEM), respectively. Thicknesses of all these samples were determined using Surface Profiler. The results are interpreted. 相似文献
23.
Hamidreza Ghandvar Saeed Farahany Jamaliah Idris 《Materials and Manufacturing Processes》2015,30(12):1442-1449
The effects of SiCp treatment and magnesium addition on microstructural and mechanical properties of Al356/20 wt% SiCp semisolid composites were investigated. The results showed that cleaning and oxidizing of SiCp and addition of 1 wt% Mg resulted in improving wettability, incorporation, and uniform distribution of SiCp in A356 matrix. Consequently, the ultimate tensile strength (UTS) value increased by 19% and 32% when the SiC was treated and also when Mg was added, respectively, compared to as-received SiCp. In addition, hardness value increased from 69.7 HV in as-received SiCp to 94.8 HV after SiCp treatment and addition of Mg. 相似文献
24.
Takayasu's arteritis is a chronic inflammatory arteriopathy. It mainly affects the aortic arch and its main branches. The aortic valve annulus and coronary and pulmonary arteries are rarely affected. Mitral and tricuspid annular calcification were not reported previously. We identified mitral annular calcification by using transthoracic echocardiography in 3 patients with Takayasu's arteritis, in whom none had any of the reported causes of mitral annular calcification. Two of them had concomitant tricuspid and aortic annular calcification. 相似文献
25.
In view of the unique properties of poly (p-benzamide), particularly as a fibre, the synthesis of the structurally related poly (p-benzenesulphonamide) has been investigated. This first paper describes the preparation of two groups of possible precursors of the polymer starting with sulphanilic acid. The first group includes N-sulphinylaniline-4-sulphochloride, aniline-4-sulphochloride hydrochloride and aniline-4-sulphochloride. The key to the synthesis of these intermediates is the conversion of sulphanilic acid to N-sulphinylaniline-4-sulphochloride by reaction with thionyl chloride in the presence of a catalytic amount of dimethyl formamide. For the synthesis of poly (N-methyl-benzenesulphonamide), N-methylsulphanilic acid has been converted into N-methylaniline-4-sulphochloride hydrochloride by treatment with thionyl chloride. Some N-acetylated sulphanilic acid derivatives, CH3CONH-C6H4-SO2X, where X?OH, OEt, OC6H5 and Cl, and N-acetyl-1-naphthylamine-4-sulphochloride have also been prepared for evaluation as monomers in the synthesis of polysulphonamides by melt polymerisation. 相似文献
26.
Hariyadi Soetedjo S. Ezrol Esham Idris Sabtu Y. Mohd Razman A.M. Abdul Fatah 《Microelectronics Journal》2006,37(10):1115-1118
Characterizations on the pseudomorphic High Electron Mobility Transistor structure under High-Resolution X-ray Diffraction (HRXRD) have been carried out at room temperature. Variation of Al contents in AlxGa1−xAs alloys has been found to show a shift of diffraction peaks. This variation is also found to show the change of lattice constant of crystal and also sheet carrier concentration as obtained from a Hall effect measurement. The latter phenomenon is considerably interesting to study in the early stage of the electrical properties of device based on the crystal structure. 相似文献
27.
Hariyadi Soetedjo O. Mohd Nizam Idris Sabtu J. Mohd Sazli Ashaari Yusof Y. Mohd Razman A.F. Awang Mat 《Microelectronics Journal》2006,37(6):480-482
Various pseudomorphic High Electron Mobility Transistor (pHEMT) structures of AlGaAs/InGaAs alloys have been observed their current-voltage behavior. The tungsten probes were used for a measurement the structures by ramping the voltage from −5 to 5 V and measure the electrical current. Measurement was carried out at room temperature and also under optical illumination. From the measurement, the electrical current was found to increase as the increase of Al content in the AlGaAs alloys layer in the pHEMT structure. This phenomenon was supported by the decrease of sheet resistance as obtained from Hall effect measurement. Under visible light illumination, the current-voltage behavior of pHEMT structure was observed to vary as the light power density was varied for 0, 25 and 55 μW/cm. 相似文献
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