Advanced Materials Research Vols. 535-537

Abstract: The changes, on stress-strain curve of coarse yak hair piece with different pretreating condition, have been analyzed during stretching slenderization in this paper. The result shows that the reagent of pretreatment could break the S-S bond effectively to prepare for stretching, and the pretreatment reagent will damage the structure of yak hair fiber if the pretreating time is more than 10min. From curve analysis, it shows that the stretching speed raising will cause the strengthening point brought forward and the yak hair fiber will bear more action force when stretching, and slow stretching could reduce the damage effectively to the structure of yak hair fiber. In addition, part of fibers would have some slippage or breakage on yak hair pieces when stretching slenderization happen.

Abstract: In view of the discrimination difficulty of bast fiber in the market, the optical microscope and SEM were used to distinguish the breed of bast fiber. The results showed that bast fiber can be distinguished from diverse fibers by optical microscope, and then the specific breed of bast fiber can be distinguished by SEM.

Abstract: Self-assembly of surfactants at air-water interfaces are widely used in the process of forming thin films for various applications. However, methods of determining fundamental properties of molecular scale interactions of these floating monolayers involve complicated processes. In this study, Langmuir-Blodgett method was used to generate surface pressure-area isotherms, which were manipulated to determine various mechanical and thermodynamic properties of Chlorophyll-a surfactants crucial in understanding molecular level interactions crucial in bottom-up design architectures. Results demonstrated optimum Chlorophyll-a concentration at 2.0 mg/ml of giving proper molecular area at zero surface pressure at 86.7 Å2/molecule. Using the elastic modulus profile, deposition pressure for close-packed phase is calculated as 26 mN/m. Young’s modulus meanwhile was measured as 0.04 GPa corresponding to about 6000 psi of pressure, which is between the values exhibited by rubber (0.01 to 0.1 GPa). Close-packed Chl-a monolayer was observed to have properties similar to rubber, with its Poisson’s ratio calculated at about 0.55. The results measured illustrates that the method could be employed to scrutinize deposition conditions and film characteristics for Chl-a molecules and other amphiphilic materials in the fabrication of bio-devices.

Abstract: Abstract: Determination of multi-elements were studied in the food cooked with medicinal herbs Ophiopogon japonicus（OJ） and Lotus seeds by ICP-AES after HNO3-H2O2 digestion with microwave. The average recoveries are in 91.7%~ 102.4% of As, Cr, Se, Cd, Cu, Mn, Zn, Al, Ba, Fe, Ni, respectively. The relative standard deviation(RSD)is less than 2.8% except Al （9.4%）and detection limit is in the range of 0. 10µg/L ~8.5µg/L except Al （79.6µg/L）. The difference was very obvious（p0.001,except As） that the elements’ content on the comparison OJ with Lotus seeds. There was rich of the trace elements Cu, Zn. The harmful element Al was on the high value（214.7µg/g）in the OJ. It is of important significance to assess the value of the food cooked with medicinal herbs by determination of multiply elements in Lotus seeds, and OJ with ICP-AES. Keyword: multi-elements, the trace elements, the harmful elements, Ophiopogon japonicus, Lotus seeds, ICP-AES

Abstract: At present, the domestic pipe string on layered polymer injection is mainly focused on the layered polymer injection technology with the hollow single pipe string, but it's limited by facts such as complicated operating and retrieving, subjecting to plugging, and single injection fluid system for each and every zones in a well. This paper starts with the idea of concentric string, directing at the construction about the profile controlling on the injection well which has 2-section or 3-section, the layered injection technique of 2-section with tubing-casing and 3-section with concentric string is investigated separately. Based on the actual formation section properties, relatively independent injecting channels are established from wellbore, and its technical proposal and corresponding tools are preceded. Now the technique has been successfully performed on 15 wells, meeting the requirements of the layered profile controlling by injecting different fluid system and displacement as well as different concentration to different layers.

Abstract: In this paper, the isothermal crystallization kinetics of isotactic polypropylene (iPP) and iPP with 5% hyperbranched polymer (HBP) added had been investigated by differential scanning calorimetry (DSC). The results show that a small addition of HBP affects the crystallization behavior of iPP. During isothermal crystallization, the crystallization rate of the blend is higher than those of iPP remarkably. An increase in the Avrami exponent may be attributed to the fractal structure of hyperbranched polymer. The crystallization activation energy is estimated by the Friedman equation, the results show that the activation energy decreases remarkably by addition of HBP and the crystallization rate of the blend is more sensitive to temperature than that of iPP.

Abstract: Electrospraying is inexpensive and an effective way to produce submicron range coating. Spray Angle and Jet Length are important characteristics that affect coating quality while polymer solution subjected to electrospraying. It was of interest to determine the effect of the process parameters on Jet Length. In this paper, an attempt was made to apply the electrospraying concept for coating textile surfaces. Series of experiments were carried out employing different settings of process parameters such as voltage, nozzle-collector distance and polymer concentration. Thermoplastic polyurethane dissolved in tetrahydrofluran was used as a solution. The results provide some insight into the effect of electrospraying process parameters on Jet Length

Abstract: The flame retardants used for the rigid PU foam material were studied systematically in this paper and a series of experiments were carried out to test the oxygen index (OI) of it. The synergistic effect in the different flame retardants also be verified to achieve a well flame retardancy performance. The best ingredients were found out by an orthogonal experiment which can give the PU foam maeterial a difficult combusted degree with the oxygen index higher than 34.

Abstract: Ultraviolet (UV) curable waterborne polyurethane(WPU) dispersions based on isophorone diisocyanate(IPDI), polypropylene glycol(PPG), dimethylolproprionic acid(DMPA) and pentaerythritol triacrylate(PETA) were prepared by the conventional method of anionic aqueous polyurethane dispersions. The structure of the ultraviolet (UV) curable WPU dispersions was studied by FT-IR. Stability, dispersion particle size and zeta-potential of the WPU dispersions were characterized. Effect of temperature on viscosity of the dispersions with different C=C content was also investigated. Results showed that all UV curable WPU dispersions had high solid content (48wt%) and showed remarkable mechanical stability. The viscosity of the dispersions decreased with temperature increasing from 20°C to 60°C. When C=C content varied from 0 to 1.05meq/g, the dispersion particle size was under 300nm, zeta potentials were less than -48.9mV.

Abstract: The polymer system in low interfacial tension conditions is a important technology in oilfield production. Through the Using both rheometer(HAAKE RS150) and interface tension instrument(TS500), the effect of interfacial tension character and viscosity caused by the changing of polymer mass concentration is studied in 30 degrees celsius condition. The man-made core displacement oil experiments and visual model displacement oil experiments were carried out, the displacement efficiency of polymer solution with low interfacial tension after water flooding or polymer flooding was analyzed. The results indicate that the interfacial tension between polymer system with low interfacial tension and oil first reduced, then increased with the increasing of polymer mass concentration, when the polymer mass concentration changes form 0.5gram/Litre to 1.5gram/Litre, the interfacial tension is 10-3 milli-Newton/meter order of magnitude, when the polymer mass concentration increased to 2.0gram/Litre, the interfacial tension is 10-2 milli-Newton/meter order of magnitude. With the changing the polymer mass concentration of polymer system from 0.5gram/Litre, 1.0gram/Litre and 2.0gram/Litre, the viscosity of polymer system with low interfacial tension increased obviously. The recovery ratio can be enhanced further by polymer solution with low interfacial tension after both water flooding and polymer flooding.