Advanced Materials Research Vols. 391-392

Abstract: Residue of alloy anode generated in three-layer liquid electrolytic purifying method is refined, the state of iron in raw materials is analysed. The state (morphology) changes of iron refined by different refining agent are investigated. Results show: 40% of boron salts or phosphate as the main component of refining agent adding 15% NaCl、20% KCl、15% CaF₂、5% NaF、5% cryolite, melting the residue of alloy anode at 1100°C and 1200°C respectively, the crystal could be incubated to grow up fully, it is benefit for collecting iron. When the soaking time is 150min, iron component in alloy is 4.8%,it reaches the standard taking back into the aluminum refining process.

Abstract: In this paper, we mainly investigated the properties of fluorinated polyimides film materials. Two aromatic dianhydrides, PMDA and ODPA were poly-condensed with four fluorinated diamines to prepare fluorinated polyimides by the two-step thermal imidization process. The properties of these polyimides were characterized by IR, TGA and UV-vis instrument. The organosolublility of these polyimides was tested in various organic solvents, such as NMP, DMF, DMAc. In addition, the effect of monomers’ molecular structure on the optical, soluble and thermal properties of these polyimides was also studied.

Abstract: An intensified continuous mini-reactor is introduced, to replace traditional discontinuous reactor, using in three-phase catalytic slurry hydrogenation. Under high pressure intensification, continuous mini-reactor behaves excellent performances of mass transfer and heat transfer, and presents the advantages of smaller volume, faster reaction rates, higher conversion and no solvent addition. The steady-state mathematic model is established, and the characteristic times of mass transfer and heat transfer are analyzed based on mass balance and energy balance Eq.s, the results can efficiently help the reactor design and optimization.

Abstract: By controlling the comonomer composition, the use of emulsion polymerization and in the condition of a certain stirring rate, a reaction temperature and a reaction time, the synthesis of a novel water-soluble acrylic acid compounds is produced. We also studied the adhesion of the acrylic copolymer T/C yarns, as the textile warp sizing materials, the performance of recycling after desizing under mild aqueous conditions. Application of the polymer sizing, can not only get energy conservation, but also protect the environment.

Abstract: Pure spinel phase LiNi_0.5Mn_1.3Ti_0.2O₄ is synthesized. A mixture of LiAc•2H₂O, Mn(Ac)₂•2H₂O, Ni(Ac)₂•4H₂O and Ti(OCH₃)₄ is used as starting material. Ethanol and citric acid are also added. The calcining process is carried out at 900 °C for 4 h. It is then followed by a thermostatic process at 600 °C for 6 h. XRD analyses indicate that the product LiNi_0.5Mn_1.3Ti_0.2O₄ is formed with F3dm structure. The SEM image shows that the particle sizes of product LiNi_0.5Mn_1.3Ti_0.2O₄ are 0.5-2 um. It exhibites excellent electrochemical performance. The discharge capacity of product cycled at 1 C (148 mA g⁻¹) rate is about 130.2 mAh g⁻¹ in the voltage range 3.5–4.9 V (versus Li⁺/Li) and the capacity retention is about 97% at the 50th cycle.

Abstract: The one-step synthesis of methyl isobutyl ketone from acetone (MIBK) and H₂ in liquid phase was studied over Ni-zirconia catalyst prepared by precipitation. The performances of Ni/ZrO₂ catalysts were evaluated by the conversion of acetone and the selectivity of MIBK. The effect of different preparation conditions such as aging temperature, calcination temperature, nickel content and reduction temperature was investigated. The results showed that high acetone conversions of up to 33% and MIBK selectivities of up to 85% were recorded at a nickel content of 13.0 wt % and the reduction temperature of 400°C.

Abstract: A novel cationic gelatin graft copolymer was developed by the graft copolymerization reaction of gelatin with acrylamide (AM) and methacryloyloxyethyl trimethylammonium chloride (DMC) in this paper. The structure of graft copolymer was analyzed briefly by the analysis of infrared spectrum, and it was found that monomers (AM and DMC) actually were grafted onto the backbone of gelatin. The effect of reaction conditions such as the weight ratios of AM/gelatin or AM/DMC on grafting parameters and the application of the cationic graft copolymer as the dry strength agent in papermaking were investigated. Experiments showed that a graft copolymer with high the percent grafting and the grafting efficiency could be obtained by controlling the AM/gelatin weight ratio and AM/DMC weight ratio. The application test showed that the results obtained from the physical intensities of handsheets under the treatment of the grafted gelatin [gel-g-P(AM-co-DMC)] were great better than the control sample, which was due to the hydrogen bonds and ionic bonds among fibres in pulp and cationic graft copolymer.

Abstract: VAc/Veova10/MAA copolymer latex containing carboxyl groups was synthesized by the semi-continuous seed emulsion polymerization with vinyl acetate (VAc), vinyl ester of versatic acid (Veova10) and methacrylic acid (MAA). Alkali-thickening characteristics of VAc/Veova10/MAA copolymer latex containing carboxyl groups, adjusted from pH 5.5 to 6.4, 8.9, 9.8 with NaOH aq., were investigated by DSC. The results showed that the viscosities of VAc/Veova10/MAA copolymer latex were increased with the inceasing of pH, The frozen temperature peaks were observed to increase with the increasing of pH, the thawed temperature peaks were shifted to lower temperature, and the state of water in latexes were different. The partial morphologies of latexes were irregular and latexes were pseudoplastic fluid. And water absorption of films were increased with the increasing of pH in latexes and dry and wet shear strengths were also decreased.

Abstract: The acicular γ-FeOOH powders were synthesized by liquid-precipitation and air-oxidation method using FeCl2•4H2O as raw material. The affecting factors, which consist of alkaline ratio (OH-/Fe²⁺), reaction temperature and dropping speed of alkaline, were discussed. From the results, it was shown that when the ratio of OH-/Fe²⁺ was controlled in the range of 0.6-1.2 in the crystal seeds formation process, the pure phase of γ-FeOOH can be formed. When the ratio of OH-/Fe²⁺ was lower than 0.6, the γ-FeOOH crystal seeds could not be formed. While the ratio of OH-/Fe²⁺ was higher than 1.2, the phase of Fe3O4 appeared. According to the principle of chemical kinetics and chemical thermodynamics, the phases of α-FeOOH and Fe₃O₄ appeared when temperature was higher than 30°C. In the process of the crystal seeds growth, the suitable reaction temperature was at 50°C.

Abstract: LiFePO₄ powders were synthesized from LiOH•H₂O, FeSO₄•7H₂O, and H3PO4 via the hydrothermal process at 200^。C . The particle sizes, morphology and electrochemical performance of the as-synthesized LiFePO₄ particles varied from the pH value, reaction time and solution concentration of the precursor. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and galvaostdtic charge-discharge tests. The results indicated that the samples with carbon coating after reacting at pH value of 9 for 4h exhibited good rate capability, which had small particle size and plate-like morphology.