Advanced Materials Research Vols. 989-994

Abstract: A technique for simultaneous determination of Ru, Zn and Zr in waste Ru-Zn/ZrO₂ catalysts using ICP-OES after sample digestion by high temperature fusion with KOH-KNO₃ mixture was described. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of KOH-KNO₃ mixture and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru, Zn and Zr for tested solutions were 11, 8 and 5 ng mL^-1, respectively. The relative standard deviations (RSDs) for Ru, Zn and Zr were 2.01, 2.55 and 1.92 % (C_{Ru, Zn, Zr} = 1 mg L^-1, n = 7), respectively. The linear ranges of calibration graphs for Ru, Zn and Zr were 0 ~ 100.00 mg L^-1, 0 ~ 50.00 mg L^-1 and 0~60.00 mg L^-1, respectively. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Abstract: In this paper, soil-water coupled dynamic analyses are carried out to investigate the influence of stratigraphic composition on the propagation properties of the seismic waves. SYS Cam-clay model is used as the constitutive model which can describe the different state of clayey and sandy soils. Two cases are considered for the composition of ground: one is the sandy ground with diluvial sand, alluvial sand and reclaimed sand; the other one is the clayey layer at the ground surface. It is found that for the sandy ground even though there is certain amplification of the input acceleration wave during the dense sand layer the subsequent seismic waves through the loose sand layers are attenuated significantly due to the occurrence of the liquefaction. While for the clayey ground, even though there is no risk of liquefaction damages at the ground surface the acceleration amplitude is greatly amplified and there is a risk that the structure itself would fail in the strength.

Abstract: The effect of MgO addition on SO₂ tolerance of MnO_x for the NO catalytic oxidation was investigated in this work. MgO addition significantly promotes the SO₂ resistance of MnO_x at low temperature range of 50–250°C. The slight decrease in catalytic activity over Mn-Mg-O_x exposure to SO₂ is attributed to the partially deactivation of the catalytic active site poisoned by SO₂. Through XRD and FT-IR characterization, MgO may effectively inhibit the competitive adsorption between NO_x and SO₂ in manganese site, and enhance SO₂ adsorption on the magnesia surface.

Abstract: Novel thermoresponsive dendronized monomer bearing azobenzene moiety, 4-(4′-(3, 4, 5-tris (2-(2-methoxyethoxy) ethoxy) benzyloxy) phenylazo) benzyl methacrylate, has been successfully synthesized. The chemical structures of intermediate compounds and dendronized monomer were confirmed by FTIR and ¹H NMR. The phase transition behaviors of these intermediate compounds and dendronized monomer were investigated. These intermediate compound and dendronized monomer showed remarkably reversible thermoresponsive phase transition behaviors.

Abstract: We synthesized a novel polymeric functional ionic liquid (IL), i.e. poly [(N-isopropylacrylamide)-co-(ionic liquid)] (P(NIPAAm-co-IL)), which can make multi–walled carbon nanotubes (MWCNTs) well dispersed in water. This method is a noncovalent technique, and the resulting solution was sensitive with temperature.

Abstract: Titanium alloy structure is an indispensable structure in aviation industry. It has high sensitivities for gap, scratch and other surface defects. Therefore, it is easy to produce various damages, such as crack, scratch and break. This paper describes a new laser rapid repair system which solves the technical problem that modern aviation titanium alloy components can not be repaired by conventional repair techniques. The rapid repair for titanium alloy components can be achieved by means of it. Meanwhile, the repair quality of aviation titanium alloy structure can be improved.

Abstract: A method of supercritical CO₂ fluid extraction gas chromatography-mass spectrometry (GC-MS) was developed for the determination of 2 novel brominated flame retardants (BB-153 and TBECH)) in flexible polyurethane foam. The optimum conditions as follows: extraction temperature: 60°C, pressure:30Mpa, CO₂ mass flow rate: 8g/min ,flow rate of methanol entrainer: 3mL/min and extraction time: 60min. The calibration curves were linear in the range of 0.1~50μg/mL with correlation coefficient of 0.9995~0.9999 and detection limits (S/N=20) of 0.05μg/mL. The average recoveries of the target compounds in sample were in the range of 97.3%~98.8%(BB-153)、99.2%~105.8% (TBECH) respectively. The results showed that this method was sensitive, reliable and environmental for the determination of 2 novel brominated flame retardants (BB-153 and TBECH)) in flexible polyurethane foam.

Abstract: Different flexible polyurethane foams (FPUF) were prepared with one step method. Combustion performance of them were tested throughout oxygen index (OI), cone calorimeter (Cone). The results showed that flame performance prepared by 10% wt brominated flame retardants, and 10% wt MPOP was better. In irradiance 30kW/m², sample thickness 50mm conditions, heat release rate peak seprarately decreased to 284.0 kW /m² and 270.8 kW /m². In the coordination of N and P, the FPUF adding MPOP showed ideal flame retardancy .It is worth noting that when the content of MPOP exceeds 10%, the physical performance decreased rapidly with the increases of brittleness and hardness.

Abstract: The study investigates the influence of different fraction of Mg₂B₂O5 whiskers (5, 10, 15 and 20vol.% ) on the microstructure of the hot extruded composite as well as on the mechanical properties in the same condition. The results indicate that the process is available for producing the composite, image analysis shows the whisker tends to cluster together with increasing content of reinforcement. When the content of the reinforcement is 10%, the composites exhibit the best mechanical properties, meanwhile, it demonstrate cluster is unfavorable to the improvement of properties of materials. The ductile failure of 6061Al matrix, the reinforcement fracture and the whisker-matrix interface debonding acted as the main mechanism of fracture nucleation.

Abstract: Low density polyethylene (LDPE) films contains BHA, BHT or BHA, BHT, TA were successfully produced by extrusion. Three types of antioxidant films that were L(LDPE), LBB(LDPE+0.5%BHA+0.5%BHT), and LBBT(LDPE+0.5%BHA+0.5%BHT+0.5%TA) was designed. The Mechanics, moisture permeability, scanning electron microscopy (SEM) and antioxidant activity of the film were detected. The results showed that antioxidant consisting of BHA, BHT and TA has a better compatibility with LDPE film. The antioxidant film has a better performance on mechanical strength and the rate of DPPH radical scavenging ability, but poor to water vapor transmission rate.