Advanced Materials Research Vols. 1120-1121

Abstract: NiAl matrix composites reinforced with a-Al2O3 and TiB2 were fabricated by microwave synthesis from Al-TiO2-B-Ni system. The reaction process and microstructures were analyzed by using differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM).The results showed that the ignition temperatures of the reaction heating by microwave and conventional method were approximately 556°C and 592°C respectively. Furthermore, the fabrication time by microwave synthesis was about several minutes, which was much shorter than two hours spent usually in conventional heating method. The a-Al2O3 phase aggregated at the trigonal grain boundary of the NiAl matrix, and the TiB2 phase distributed uniformly in the NiAl matrix.

Abstract: The silica gel surface was alkylated by silane coupling agent KH-570 under the microwave assisted and orthogonal experiment was adopted to optimize the silica gel surface silanized experimental conditions with synthetic yield as index. With quercetin as the template molecule, 4 - vinyl pyridine as the functional monomer, ethylene glycol dimethyl acrylate as the cross linking agent, azodiisobutyronitrile as initiator, under the microwave assisted in silane silicone surface quercetin molecularly imprinted polymer was successfully synthesized. Take selected quercetin as index, another orthogonal experiment was implemented to optimize the quercetin-selective MIPs synthesis experiment on silica gel surface. What is more, the adsorptive property of quercetin-selective MIPs which was grafted on silica gel surface has been inspected. We have extracted of quercetin in the ethyl acetate from raspberry with quercetin-selective MIPs grafted on silica gel surface. Synthetic time have been shortened more than a dozen times, the efficiency of preparation of MIPs have been greatly improved.

Abstract: Acrylonitrile (AN) and itaconic acid (IA) were used to synthesize UHMWPAN by aqueous suspension method with 2,2’-azobisisobutyronitrile (AIBN) as the initiator and polyvinylalcohol (PVA) as the disperser at different temperatures (55°C~75°C) for different timings (1.0h~3.0h). The usage amounts of AN, IA, AIBN and PVA were also technical polymerization parameters used to obtain the optimal polymerization process. We found that the conversion and the viscosity average molecular weight both achieved the optimum levels when the conditions were as follows: the total monomer concentration (21wt%), the monomer ratio (AN: IA=98:2), the usage amount of the initiator (AIBN, 0.01wt%), the usage amount of the disperser (PVA, 0.1wt%), the polymerization temperature (70°C) and the polymerization time (2h).

Abstract: PBO (p-phenylene benzobisoxazole) short fibers, attached fine fibrils that are called PBO pulp, may precipitate directly from stirred PBO/methanesulfonic acid (MSA) solution by the use of water coagulant in fibrous pulp form. Scanning electron micrographs show that the precipitated PBO pulps have a ribbon-like structure similar to Kevlar pulps. The thermalgravimetric analysis (TGA) show there were no appreciable mass changes until 550 °C in the air. The process yields PBO pulps with different specific surface areas (SSA) depending on the stirring speed, stirring time and the concentration of the PBO/MSA solution. High SSA PBO pulps can be produced by increasing the stirring speed, prolonging the stirring time and reducing the concentration of the PBO/MSA solution.

Abstract: PTT/EVA-g-MA (80/20 w/w) nanocomposites were prepared by the melt mixing with different organoclay (OMMT) loading. The effect of OMMT on the non-isothermal crystallization kinetics of composites was investigated by DSC. The Avrami and Ozawa methods were used to describe the non-isothermal crystallization process of pure PTT and composites with various loading of OMMT. The Avrami analysis results show that the crystallization rate of 80/20 (w/w) PTT/EVA-g-MA blends with the OMMT is faster than that of pure PTT. The Ozawa analysis can describe the non-isothermal crystallization of pure PTT very well, but it was rather inapplicable for the 80/20 (w/w) PTT/EVA-g-MA blends with various amounts of the clay.

Abstract: In this article, a kind of synthetic polymer dust suppressants agent was prepared with poly (vinyl- alcohol) (PVA), carboxymethylcellulose (CMC) and acrylamide (AM). The chemical and physical properties of this dust suppressant was characterized by means of grafting rate, FT-IR analysis, TG test, viscosity analysis and SEM survey. The result showed that grafting rate was reached 95.6%; IR spectrum proved that monomers have been completely reacted basically; thermal gravimetric analysis was characterized that the dust suppressant has good thermal stability between 0°C-250°C; the amount of AM and SDBS were 50% and 1.0% (based on mass of the total materials), the polymer has a suitable viscosity; SEM was used to observe the shape characteristic of the coal dust which formed a link between the dust suppressant and coal dust. The water resistance of the dust suppressant was well in 24h.

Abstract: A series of novel organoclay(OMMT)/super-absorbent resin composites were prepared using the waste of PAN fibers at alkaline hydrolysis condition with Al₂(SO₄)₃ as cross-linker. The effects of OMMT content on the chemical structure and degradation of the super-absorbent resin were investigated. The swelling behavior was also evaluated. The swelling rates of super-absorbent resin went up with increasing OMMT loading to 3wt% and then decreased with further increasing OMMT loadings. OMMT-based super-absorbent resin might have potential applications in many areas, such as construction engineering and hygienic products.

Abstract: New trends in development and research of construction polymeric materials allow modification of their properties. This change of properties may represent a significant financial burden, which will be reflected in the product price. This article will consider the degree of impact of such modification on finished products. Improving creep characteristics are not directly proportional to the amount of the dose. Moreover is solved the dose amount compared to the value added, which will translate into better mechanical properties. The results of these measurements show that the most appropriate dose of radiation in terms of the mechanical properties of the dose is 198 kGy. However, in terms of value added seems best a much smaller dose.

Abstract: To reduce the loss of fresh fruits during transportation and storage, an active packaging (AP) material which could control release fungicide was prepared by melting, blowing film and composite method firstly. Then, its preservation effects on strawberry at different storage temperatures were investigated systematically. Several properties of preserved strawberries were measured periodically, including gas concentration of the package atmosphere and the physiological parameters contains decay rate, total solid content, as well as the sensory and taste evaluation were measured. The experimental results show that this AP material is helpful to fruit preservation, especially at lower temperature. It can prohibit the strawberry respiration, retard fungus growth and thus significantly extend the shelf-life of fresh strawberry.

Abstract: Carbon fibers are usually used in the form of filaments since they are low in expandability and quickly wear and tear by bending. However now with the development of spinning technology, twisted carbon fiber yarns have been produced. In order to investigate the slashing and weaving properties of twisted carbon fiber yarns slashed by polyacrylate sizing agent at the room temperature, size picks up, tensile strength and abrasion resistance were introduced. Furthermore, a small piece of plain fabric was finished on the sample weaving machine. The results prove that slashing with polyacrylate sizing agent improves the slashing and weaving properties of twisted carbon fiber yarns significantly. Further, when the solid containing rate of polyacrylate slurry was around 5%, the size picks up can be up to 5.5%, the tensile strength increases by 19.8% and the wear resistance increases by 66.7%. Moreover, by using high-temperature water bath downsizing method, the sizing agent subsided frequently.