田菁胶的理化性能

叙述了从不同渠道收集的 12个样品理化性能的测定结果。结果表明 :改性后的田菁胶各种性能指标均接近国外进口的瓜尔胶 ,是瓜尔胶理想的替代品     

Physical and chemical properties of soybean proteins

Recent physical and chemical studies are reviewed for Bowman-Birk and Kunitz trypsin inhibitors, agglutinin, and 7S and 11S globulins of soybeans. Differences between gelation properties of crude 7S and 11S globulin fractions are also discussed.     

Physical and chemical properties of ethanol-diesel fuel blends

This paper discusses the physical-chemical properties of ethanol-diesel fuel blends. The attention is focused on the properties which influence the injection and engine characteristics significantly. Main properties have been investigated experimentally. The analysis of experimentally obtained fuel properties of tested fuels and their influence on engine characteristics are presented. Physical and chemical properties of diesel fuel and ethanol-diesel fuel blends were measured according to requirements and test methods for diesel fuel (EN590, 2003). The tested fuels were neat mineral diesel fuel (D100), 5% (v/v) ethanol/diesel fuel blend (E05D95), 10% (v/v) ethanol-diesel fuel blend (E10D90) and 15% (v/v) ethanol-diesel fuel blend (E15D85). It has been proved that, for ethanol-diesel fuel blends, some additives are necessary to keep stability under low temperature conditions. Also, cold weather properties test, such as cloud point and pour point tests are negatively affected by phase separation. The rest of the properties, excepting flash point, were within diesel fuel standard specifications. Based on this study, it can be concluded that using additives to avoid phase separation and to raise flash point, blends of diesel fuel with ethanol up to 15% can be used to fuel diesel engines if engine performance tests corroborate it.     

Physical and chemical properties of alumina bleached cottonseed oil

No detectable amount of polymerization or triene conjugation occurred on bleaching refined cottonseed oil with either activated alumina or with sulfurous acid-treated alumina, although insignificant amounts of diene conjugation andtrans- isomerization occurred. AOM stability, tocopherol content, and fatty acid composition, as determined by gas-liquid chromatography (GLC), were comparable with values obtained with oil bleached with natural earth. Hydrogenation of the oils proceeded normally. Taste panel evaluations of the deodorized oils revealed their flavor stability to be equal to that of the same oil bleached with AOCS official earth.     

多核金属配合物合成及其催化性能研究进展

综述了不同类型多核金属配合物的合成及其催化性能等方面的研究进展。主要从双核、三核及多核金属配合物等方面进行展开。又根据金属种类的不同,分为同核或杂核金属配合物。多核金属配合物在均相催化与材料化学等研究领域表现出优越的性能,为合成不同类型的多核金属配合物及其催化性能研究提供参考。     

多核金属配合物合成及其催化性能研究进展

综述了不同类型多核金属配合物的合成及其催化性能等方面的研究进展。主要从双核、三核及多核金属配合物等方面进行展开。又根据金属种类的不同,分为同核或杂核金属配合物。多核金属配合物在均相催化与材料化学等研究领域表现出优越的性能,为合成不同类型的多核金属配合物及其催化性能研究提供参考。     

Synthesis and properties of novel end-functionalized polybutylacrylate and its metal complexes

Summary Well-defined polybutylacrylate (PBA) was prepared by atom transfer radical polymerization (ATRP). A novel end-functionalized PBA (macromolecular ligand) was synthesized via PBA bonded with thiocarbamide. Since thiocarbamide possesses strong chelating ability, end-functionalized PBA possesses some new properties such as coordination with metallic ions. After metallic ions were introduced into it, two kinds of end-functionalized PBA metal complexes were got. The structure and property of PBA, end-functionalized PBA and its metal complexes were characterized by ¹H NMR, UV, GPC, Atomic Emission Spectrometry (AES), Cyclic Voltammogram (CV) and Dielectric Constant. The results indicate that the properties of end-functionalized PBA with well-defined structure were improved greatly by introducing a small quantity of transitional metallic ions into it. The novel end-functionalized PBA metal complexes exhibit stable electrochemical activity, dielectric property and have a good prospect in many fields as functional polymer.     

Physical chemical properties of solutions of bis-quaternary ammonium bromides

The physical chemical properties of a series of bisalkyldimethyldi-ammonium polyoxyethylene bromides were studied by measuring the critical micelle concentrations as function of their molecular structure. The conductivity vs. concentration plots revealed the existence of two distinct discontinuities which were labeled CMC1 and CMC2. The CMC1 was always lower than the CMC2. The conventional surface tension vs. log concentration curve showed the classical sharp break which coincided with either the CMC1 or the CMC2, but failed to reveal the presence of both critical micelle concentrations in the same experiment. The existence of two CMC2 was attributed to the presence of the two charges localized in separated atoms. The CMC1 and CMC2 appear to follow an expression of the type CMC=A —Bn, where A and B are constants and n the number of carbon atoms present in the hydrocarbon long chain attached to the quaternary ammonium nitrogen. The CMCs appear to increase with the increasing number of oxyethylene residues up to a certain length of the polyoxyethylene chain. For most compounds there was a substantial drop in surface tension with the increasing concentration of the salt. However, some compounds containing only one oxyethylene residue showed practically no surface tension dependence on concentration although the critical micelle concentrations were apparent in the conductivity vs. concentration curve. The energy to transfer one methylene group from the aqueous to the micellar phase was found to vary from −0.57 kT to −0.84 kT. The alkylene oxylated bisquaternary bromides studied appear to have unusual physical chemical properties.     

Physical and electrochemical properties of synthesized carbon nanotubes [CNTs] on a metal substrate by thermal chemical vapor deposition

Multi-walled carbon nanotubes were synthesized on a Ni/Au/Ti substrate using a thermal chemical vapor deposition process. A Ni layer was used as a catalyst, and an Au layer was applied as a barrier in order to prevent diffusion between Ni and Ti within the substrate during the growth of carbon nanotubes. The results showed that vertically aligned multi-walled carbon nanotubes could be uniformly grown on the Ti substrate (i.e., metal substrate), thus indicating that the Au buffer layer effectively prevented interdiffusion of the catalyst and metal substrate. Synthesized carbon nanotubes on the Ti substrate have the diameter of about 80 to 120 nm and the length of about 5 to 10 μm. The Ti substrate, with carbon nanotubes, was prepared as an electrode for a lithium rechargeable battery, and its electrochemical properties were investigated. In a Li/CNT cell with carbon nanotubes on a 60-nm Au buffer layer, the first discharge capacity and discharge capacity after the 50th cycle were 210 and 80 μAh/cm², respectively.     

Physical and chemical properties of trans-free fats produced by chemical interesterification of vegetable oil blends

Fat blends, formulated by mixing a highly saturated fat (palm stearin or fully hydrogenated soybean oil) with a native vegetable oil (soybean oil) in different ratios from 10:90 to 75:25 (wt%), were subjected to chemical interesterification reactions on laboratory scale (0.2% sodium methoxide catalyst, time=90 min, temperature=90°C). Starting and interesterified blends were investigated for triglyceride composition, solid fat content, free fatty acid content, and trans fatty acid (TFA) levels. Obtained values were compared to those of low- and high-trans commercial food fats. The interesterified blends with 30–50% of hard stock had plasticity curves in the range of commercial shortenings and stick-type margarines, while interesterified blends with 20% hard stock were suitable for use in soft tubtype margarines. Confectionery fat basestocks could be prepared from interesterified fat blends with 40% palm stearin or 25% fully hydrogenated soybean oil. TFA levels of interesterified blends were low (0.1%) compared to 1.3–12.1% in commercial food fats. Presented at the 88th AOCS Annual Meeting and Expo, May 11–14, 1997, Seattle, Washington.     

Physical gelation of cellulose acetate propionate solutions mediated by metal carbonyl complexes

The weak physical gelation of cellulose acetate propionate-butyl butyrate solutions as a result of the in-situ decomposition of iron pentacarbonyl complexes was explored. Viscometry and infrared spectroscopy were used to monitor the iron pentacarbonyl decomposition reaction progress and its effect on viscosity. Changes in viscosity in of the cellulosic fluids in general and gelation in particular were found to be dependent upon the environment in which the Fe(CO)₅ decompositions occurred. Systems under inert atmospheres exhibited a marked increase in viscosity, while systems under oxidative atmospheres exhibited a general decrease in viscosity. We propose a hypothesis that explains the dependence of the viscosity of these cellulosic fluids as a function of the environmental conditions during the precursor decomposition. Under nitrogen atmospheres, zero-valent nanoparticles with highly reactive surfaces are synthesized, which form weak, transient bonds with the cellulosic polymer. The iron particles, under these circumstances, serve as weak bridges between adjacent polymer chains. Conversely, the primary particles synthesized under an oxidative atmosphere are metal oxides, which are less attractive to the polymer chain and, therefore, do not yield such bridges. This work demonstrates the capability to apply a simple method to control the viscosity of cellulose ester fluids.     

Synthesis and properties of functionalized β-cyclodextrin copolymer and its metal complexes

Summary A novel copolymer was synthesized successfully via polymerization of part (6-O-butene diacid ester)-β-cyclodextrin and styrene. Because the carboxyl groups of the new copolymer possess a strong chelating ability, the copolymer is capable of coordinating with metal ions. Utilizing this new ability, the copolymer metal complexes containing Cu(II) and Ag(I) were synthesized. The structures and properties of the copolymer and its metal complexes were characterized by IR, UV, MS, ¹³C NMR, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), electron spin resonance (ESR), and cyclic voltammetry (CV). The results show that the novel copolymer metal complexes were composed of the desired metal ion, polystyrene, and the functionalized β-cyclodextrin (β-CD). Furthermore, they possess stable electrochemical activity and are paramagnetic.     

Synthesis and properties of metal complexes of radiation grafted carboxyl containing copolymers

Metal complexes of copolymers based on polyacrylic acid radiation grafted onto films of low density polyethene were prepared by complex‐forming with solutions of salts of FeCl₃.6H₂O, CuCl₂.2H₂O, CoCl₂.6H₂O, NiCl₂.6H₂O, VOSO₄.5H₂O, Na₂MoO₄.2H₂O, Na₂WO₄.2H₂O, and NH₄VO₃. The introduction of metal ions was found to depend mainly on the degree of grafting of acrylic acid and was from 0.5 to 5.0 mass%. These complexes were characterized by IR, UV spectroscopy, and EPR. The moisture content of the materials obtained changed linearly with the degree of grafting of acrylic acid and was from 9.0 to 80.0%. The introduction of the MoO₂²⁺ and WO₂²⁺ towards carboxylic groups lead to increasing the thermal stability of the metal complexes of the copolymers compared to the initial grafted films. The modified acrylate copolymers were studied in reactions of catalytic oxidation of cyclohexene. The activities of the complexes obtained towards cyclohexene epoxidation can be arranged in the following order: PAA–MoO₂²⁺ > PAA–VO²⁺ > PAA–VO > PAA–WO₂²⁺, while for the reaction of cyclohexene hydroxylation the order was—PAA–Co²⁺ > PAA–Cu²⁺ > PAA–Fe³⁺ > PAA–Ni²⁺. The contents of cyclohexene oxide and 2‐cyclohexene‐1‐ol reached 38.5% and 7.5%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1658–1665, 2006     

白泥脱硫浆液与石膏理化特性

目前白泥湿法烟气脱硫已实现工业化应用,但对白泥脱硫浆液与石膏理化特性方面鲜有报道,因此对白泥脱硫浆液与石膏理化特性进行了研究。实验中测定了白泥的含水率、pH,采用XRD、XPS、激光粒度分布仪、ICP-MS、离子色谱仪、SEM等对白泥、脱硫石膏及脱硫浆液进行理化特性分析;综合考虑了造纸过程对白泥成分的影响,探讨了白泥和白泥浆液颜色变化的原因。实验和分析结果表明,白泥的理化特性和石灰石有明显差异,白泥的pH高于石灰石,含水率最高可达40%,白泥中Na、K、Mg含量高于石灰石;白泥浆液溶解性盐过高,但重金属含量较低;白泥石膏质量较好,但溶解性盐对石膏应用可能产生影响。白泥可代替石灰石作为湿法烟气脱硫的吸收剂,白泥与石灰石理化特性差异对白泥应用于湿法烟气脱硫的影响有待更深入研究。