Applied Mechanics and Materials Vols. 275-277

Abstract: Palygorskite/tung oil phenolic complex material (MP) was prepared by means of solution mixing. The scattered state of the nano-particles was characterized by transmission electron microscope (TEM). The heat resistance of which MP and SP were prepared by means of in-situ polymerization and boron modified palygorskite nanometer composite resin (BP) and P0.0 without palygorskite nano-particles were contrasted and analyzed by SETARAM TG-DSC92-16, and the four friction materials separately made of MP, SP ,BP and P0.0 were used for tests of friction by the DMS-1. The results show that palygorskite nano-particles with 0.7% in MP have fair dispersibility, and the thermal weight loss of MP compared with P0.0 falls 6%. Its heat resistance closes to SP’s and is with 50°C higher than P0.0’s. So the MP has good tribological behavior.

Abstract: The solid MoS₂ composite films which were doped with Sb₂O₃ were investigated by means of UMT-2 tribometer. The worn surface morphology of balls and discs during different worn phases were measured on a high resolution microscope. The main chemical elements S,Mo in the worn surface were analyzed with PHI-5720 XPS. The worn areas of discs during different worn phases were measured with the aid of a nano scratch meter(CSM,Switzerland) .The results showed that the MoS₂/Sb₂O₃ composite films had better oxidation resistance properties and longer wear-life(6.5×10⁵r).The model of contact between the ball and its counterpart (steel disc) was converted into flat contact during the wear test. The MoS₂ transferred from discs to the surface of the balls helped to contribute their longer wear-life. Continually accumulated wear at the interface between balls and their respective counterpart discs resulted in their lubrication failure, and the accompanying oxidation of MoS₂ occurring partially accelerated lubrication failure of the solid MoS₂ composite lubrication films.

Abstract: Sandwich composite is a new structure of acoustic stealth structure, implementing both loading and acoustic stealth. Micro-fillings can improve the sandwich absorption coefficient. The influence parameters are studied by absorption theories analysis of sandwich structure. The absorption and reflection coefficient in different categories, size and layers of fillings are analyzed by pulse tube experiments. The results shows that the first absorption peak moves to low frequency by adding fillings, the peak frequency are lower when the fillings size increase, and the absorption coefficient are higher when the thickness of sandwich layers are closed.

Abstract: Cu(Cr_0.2Al_0.8)₂O₄/TiO₂ composite film electrodes were prepared on FTO glass substrate by screen printing method after Cu(Cr_0.2Al_0.8)₂O₄ nano-particles were doped in TiO₂ powers. The characteristics were studied by the X-ray diffraction for the crystalline structure of composite films, UV-Vis diffuse reflectance spectrum instruction for absorption spectrum of composite films and dye sensitized solar cells tester for the performance of DSSC. The results show doping Cu(Cr_0.2Al_0.8)₂O₄ powers could enhance UV-Vis spectral absorption strength and improve the photoelectric conversion efficiency of the solar cells when the doping content of Cu(Cr_0.2Al_0.8)₂O₄ is 3％. Compared with pure TiO₂ film electrodes, the photoelectric conversion efficiency of the solar cells reaches to 3.59％.

Abstract: How to design the interfacial properties is a significant fundamental issue in the field of the composite materials, while little work was concerned with the mechanical design of the interface for the fiber reinforced polymer. In the present work, a fiber bundle embedded in the matrix was described as a transversely isotropic material. Based on the imperfect interface conditions, the interface parameters were derived to satisfy the neutral conditions for the composite materials reinforced by the elliptical cross-section fiber bundle. It is found that the interface parameter is not always associated with the applied loading in the case of the anti-plane shear. In the state of equal-biaxial tension, the normal interface parameter is merely related to the mechanical properties of components except for the shape of the fiber bundle, but independent of the loading magnitude. In the other cases of pure shear and uniaxial tension, the neutral interface does not exist except that the fiber bundle has a circular cross-section. It is also found that the interface parameters can be expressed in the forms similar to that for an isotropic inclusion by using Kolosov constant in the in-plane deformations.

Abstract: The spruce fiber reinforced thermoplastic polypropylene (PP) composite is studied in this paper aiming at inspecting the effect of micromechanics parameters on the effective elasto-plastic property of composite by the numerical methods. The local stress field changing with the fiber aspect ratio and volume fraction is detailed investigated. At the last the normal cohesive strength of the interface is predicted initially. The numerical results show good agreement with the theoretical prediction results and available data.

Abstract: Using the complex of quercetin and Ni+2 (quercetin-Ni+2) as template (quercetin is a kind of flavonoids which are important active ingredients of Chinese herbs.), methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker, metal-complexing template polymer has been prepared in the mixed solution of methanol and tetrahydrofuran by molecular imprinting technique. The coordination structure and complex ratio between quercetin and Ni+2 were studied by UV-visible spectroscopy, and the ternary complexation of quercetin, Ni+2 and methacrylic acid was verified by similar methods. Selective adsorption experiments for substrates indicated that compared with quercetin’s structural analogs (baicalein and baringenin), quercetin-Ni+2 template polymer prepared with appropriate amount of cross-linker exhibited significant adsorption selectivity for quercetin in the presence of Ni+2. The separation factors were 3.915 and 5.443 respectively, which also showed that adsorption capacity was greatly influenced by the amount of cross-linker.

Abstract: The microspheres(SBM) was prepared using N, N'-methylene-bis-acrylamide (MBAA) as cross-linker and K2S2O8-Na2SO3 as initiator in water-in-oil emulsion. And then the effects of the O/W ratio (v/v), the amount of cross-linker and the amount of K2S2O8-Na2SO3 on particle size and swelling ratio were investigated. An increase in particle size was observed by increasing the amount of cross-linker and the amount of K2S2O8-Na2SO3, while with decreasing the O/W ratio and the amount of K2S2O8-Na2SO3 particle size was found to decreased, which was just opposite to the trend of swelling ratio. Particle size of the microspheres is 12-65μm. Ascorbic acid was selected as a sample drug, and the function between ascorbic acid and SBM was illustrated by the three-electrode equipment. The absorption mechanism suggested that the absorption of ascorbic acid on SBM is exist and ascribes to hydrogen bond for－OH and－NH2 of SBM and －OH of ascorbic acid.

Abstract: The composites based on polyvinyl chloride (PVC) and bamboo flour were made by extruded molding. The effects of the bamboo flour content on the composite physical properties were examined. The result showed that the composite mechanical properties were due to bamboo flour content. At the same time, we also make sure the process temperature and the proportional relationship between feed rate and screw speed is 1:2.

Abstract: Ammonium polyphosphate (APP) is usually synthesized by heating diammonium hydrogen phosphate and phosphorus pentaoxide at ammonia atmosphere, in which phosphorus pentaoxide is used as condensing agent. In this paper, a new process is pointed out in which APP is synthesized by heating diammonium hydrogen phosphate and melamine to a certain temperature at ammonia atmosphere, melamine is used as the sole condensing agent, the XRD patterns of synthesized product are investigated and discussed in detail. The results are informative for controllable preparation of APP in industrial production.