高吸水性聚丙烯酸钠树脂

综述了高吸水性聚丙烯酸钠树脂的研究进展 ,其中包括聚丙烯酸钠及其共聚物的吸水性能 ,吸水机理以及其功能与应用     

高吸水性树脂粒径与性能的研究

研究了高吸水性脂粒径与性能的关系及影响高吸水性树脂粒径分布的诸因素。结果表明，粒径为８０－１２０目的高吸水性树脂吸水（液）率高，吸水（液）速度快，保水性好，与ＰＶＣ共混性优良。在搅拌速度为８０－１２０ｒ／ｍｉｎ，分散剂和助分散剂用量分别为水相重的０．４％－０．６％和８％－１２％，水／油为２．５－３．５的条件下制得的高吸水性树脂平均粒径小，粒径分布范围窄，树脂综合性能好。     

分子筛改性羧甲基纤维素类高吸水性树脂研究

以羧甲基纤维素(CMC),丙烯酸(AA),2-丙烯酰胺2甲基丙磺酸(AMPS)为原料,过硫酸钾为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,经接枝共聚制备高吸水性树脂;为提高高吸水性树脂的耐热性能,使用分子筛对高吸水性树脂进行改性,探讨了分子筛种类和用量对高吸水性树脂性能的影响,测定了改性后高吸水性树脂的吸水倍率、吸水速率、再生性能和耐热性能,通过对其性能进行比较得出:添加0.5g的13X分子筛改性高吸水性树脂效果最佳,所得产物吸水倍率为675g·g-1,吸水速率、再生性能和耐热性能也比改性前有显著提高.     

农用高吸水性树脂及其前景展望

详细介绍了农用高吸水性树脂的吸水、保水机理,分类,作用机制,性能及近年来国内外的研究进展;认为对农用高吸水性树脂吸水机理的深入研究、降低成本、改善耐盐性、改善降解性能、研制功能性高吸水性树脂等,将成为下一步农用高吸水性树脂的研究热点。     

PEO-b-PBA对天然橡胶/高吸水树脂共混体系增容作用的研究

通过扫描电子显微镜观察了天然橡胶和高吸水树脂共混体系的微观相态结构 ,研究了两亲性嵌段共聚物PEO b PBA结构本身的吸水能力对天然橡胶和高吸水性树脂共混体系吸水性能及力学性能的影响。结果表明 ,PEO b PBA结构本身的吸水强弱对共混体系的吸水能力贡献很小 ,但却可以显著提高共混体系的吸水膨胀能力和力学性能 ,对特殊的增容作用进行了探讨     

含两亲性PEO-b-PBA增容剂的吸水膨胀橡胶的制备及性能

以天然橡胶为基体，微米级交联聚丙烯酸钠为高吸水性树脂，两亲性嵌段共聚物聚氧化乙烯-b-聚丙烯酸丁酯(PEO-b-PBA)为增容剂，聚乙二醇为吸水促进荆，制备了嵌段共聚物增容型吸水膨胀橡胶。通过扫描电子显微镜观察了其微观相态结构，适量加入两亲性嵌段共聚物PEO-b-PBA可以改善CSP树脂与NR的相容性。并研究了质量吸水率，体积膨胀率以及吸水速率与各组分含量之间的关系，对体系的力学性能进行了研究，对吸水树脂的主体吸水作用及嵌段共聚物的增容作用进行了探讨。     

高吸水性HP(MA-VAC)树脂的制备与性质EI

研究了部分水解聚(丙烯酸甲酯-乙酸乙烯酯)高吸水性树脂-HP(MA-VAC)的制备与性质。讨论了合成反应工艺条件与HP(MA-VAC)树脂性能的关系。实验结果表明该吸水性树脂吸水容量大、吸水速度快、保水效果好、热稳定性高、抗盐性能好,是一种综合性能好的高吸水性树脂。     

PEO—b—PBA对天然橡胶／高吸水树脂共混体系增容作用的研究

通过扫描电子显微镜观察了天然橡胶和高吸水树脂共混体系的微观相态结构，研究了两亲性嵌段共聚物PEO-b-PBA结构本身的吸水能力对天然橡胶和高吸水性树脂共混体系吸水性能及力学性能的影响。结果表明，PEO-b-PBA结构本身的吸水强弱对共混体系的吸水能力贡献很小，但却可以显著提高共混体系的吸水膨胀能力和力学性能，对特殊的增容作用进行了探讨。     

农用高吸水性树脂及其研究进展

农用高吸水性树脂的使用是解决农业缺水、传统化肥农药对环境污染等问题的有效途径。详细介绍了农用高吸水性树脂的吸水、保水机理、分类、作用机制、性能及近年来国内外在这些方面的研究进展;认为对农用高吸水性树脂吸水机理的深入研究和对降低成本、改善耐盐性、改善降解性能的研究,以及研制功能性高吸水性树脂等将成为今后农用高吸水性树脂的研究热点。     

节水保水新产品 第四大农用化学生产材料

<正>保水剂又称土壤保水剂、高吸水剂、保湿剂、高吸水性树脂、高分子吸水剂,是利用强吸水性树脂制成的一种超高吸水保水能力高分子聚合物,因其能调节土壤水肥综合功能,保持和提高水分、养分有效性,广泛受到国内外农业专家高度重视。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.