Advanced Materials Research Vols. 881-883

Abstract: Aluminum-containing ternary carbide, Al4SiC4-Al4Si2C5 composites, were synthesized using a mixture of bauxite, kaolin and carbon black as starting materials. The effects of raw materials ratio on the phase transformation and micromorphology of ternary carbide were investigated. The results indicated that the optimum condition for synthesizing Al4SiC4-Al4Si2C5 composites was 2 h sintering at 1900 °C in flowing argon atmosphere. Al4Si2C5, Al, Si and SiC formed when carbon black content was lower than stoichiometric amount. With increasing of carbon black content, the Al and Si content decreased and Al4Si2C5 content increased in the products. Al4SiC4 appeared when stoichiometric amount of carbon black was used, and about 20 mol% excess of carbon black promoted the formation of Al4SiC4.

Abstract: Waterbased phenol-formaldehyde (PF) resin was prepared and applied to enhance the mechanical strength of aramid paper in this paper. The water dilution stability of prepared PF resin was studied. The chemical structure and the thermal stability of prepared PF resin were characterized. The comprehensive performances of aramid paper before and after strengthen by PF resin were tested. The Micro-morphology of aramid paper was observed by Scanning electron microscopy (SEM0. The results shows that the comprehensive performances of aramid paper were greatly enhanced after being strengthen by PF resin. Its expected that the prepared PF resin has promising application in aramid paper industry.

Abstract: Nanoporous nickel phosphates (VSB-1) was synthesized by hydrothermal method. Then VSB-1 was added to the ammonium polyphosphate and pentaerythritol system in polypropylene (PP) matrix.The synergistic effect of VSB-1 with intumescent flame retardants (IFR) was studied by cone calorimetry test. The results of cone calorimetry show that heat release rate peak (pHRR) and total heat release (THR) of intumescent flame retardant PP with 2wt% VSB-1 decrease remarkably compared with that of without VSB-1. The pHRR and THR decrease respectively from 1140 to 286.0 kW/m², and from 96.0 to 63.2 MJ/m².

Abstract: In this paper, in situ TiB reinforced Ti-3Al, Ti-6Al and Ti-6Al-4V matrix composites were prepared by arc-melting technique utilizing the reaction between Ti and TiB₂, and then forged in the α+β phase field. Phase identification was carried out via X-ray diffraction. Microstructure of the composites was studied by optical microscopy (OM) and scanning electron microscopy (SEM). Mechanical properties of the composites after forging were measured at various temperatures by tensile experiment. The results showed that Ti-6Al-4V-2TiB composite exhibits fine equiaxed matrix microstructure with a grain size of 5-10μm. The tensile strength and elongation of the composite at room temperature reached 1069MPa and 10.0%, respectively.

Abstract: Polymer matrices add carbon nanotubes have significantly improved mechanical and electrical properties at very low carbon nanotube loading. That mechanical and electrical properties of aligned composites are better than those of random ones has been demonstrated in past studies. The non-conductive barriers of surface contaminants and weakly bound polymer layers will deform on the surface of composite resulted from the effects of micro gravity and oxidization. Addition of the adaptive plasma modification makes improvement in the surface properties of the composites is necessary. In this study, we actively align and network multiwall carbon nanotubes (MWCNTs) in a polymer matrix, then adopt O₂/CF₄ radio frequency (RF) plasma to modify the surface of polymeric composite. MWCNTs were aligned using an AC electric field to elicit dipolar interactions among the nanotubes in a viscous matrix following immobilization by curing under continuous application of an anisotropic electric field, and the barriers of surface contaminants and weakly bound polymer layers can be reduced to the smallest degree or eliminated by RF plasma modification. Consequently, the MWCNTs polymeric composite amplify the flexural modulus, wear resistance, and electrical conductivity in the reality.

Abstract: SiO₂/PET composite packaging film was prepared by depositing SiO₂ on PET film substrates through magnetron sputtering technology. The state of SiO₂ particles and its dispersion properties in PET substrates were characterized by scanning electron microscope (SEM) and bonding strength tester. The effects of the sputtering process parameters and intermediate layer on the bonding strength of the coating-substrate system were investigated. Results show that the bonding strength of coating-substrate system firstly increases and then decreases with the increase of sputtering process parameters. It is up to a maximum at the argon flow of 10 mL/min, radio-frequency power of 250 W and sputtering time of 70 min; and it is 0.14 MPa, 0.22 MPa and 0.19 MPa, respectively. The bonding strength of coating-substrate system increases with the increasing background pressure. Meanwhile, we find that the bonding strength of coating-substrate system is improved by depositing A1₂O₃ intermediate layer between SiO₂ film and PET substrates.

Abstract: The effect of thermal setting parameters namely tensile stress, temperature and time on the breaking strength and breaking elongation of hollow polyester (PET) fiber (Porel^TM fiber) were investigated, and their synergistic effect was studied via orthogonal experiment. The results show that protection of fiber wall is an important task during thermal finishing process of hollow fiber. There are direct relationships between micro-molecular structure and mechanical properties. Orthogonal experiment analysis shows that the most significant effect factor for breaking strength and breaking elongation are temperature and tensile stress, respectively. The suggested thermal finishing conditions for Porel^TM fiber are summarized as following: elongation (viz. tensile stress) 4%, temperature 165°C, and time 60s.

Abstract: With 2,2'-biquinoline-4,4'-dicarboxylic acid disodium salt (BCA) and Zn (CH₃COO)₂·2H₂O as starting materials, a sheaflike Zn (II)-2,2'-biquinoline-4,4'-dicarboxylic acid disodium salt coordination polymers (Zn-BCA CPs) has been successfully synthesized through a simple and mild one-step process in aqueous solution at room temperature. The effects of reactant molar ratio, temperature and reaction time on the morphology of the coordination polymers have also been examined. It was found that the Zn-BCA CPs showed an greatly enhanced blue photoluminescence emission compared with Zn-free BCA.