反相悬浮法制备聚(丙烯酸-丙烯酰胺)/粉煤灰高吸水树脂

以丙烯酸和丙烯酰胺为单体,过硫酸钾为引发剂,N,N′-亚甲基双丙烯酰胺为交联剂,Span80为分散剂,环己烷作为油相,采用反相悬浮聚合法合成聚(丙烯酸-丙烯酰胺)高吸水性树脂。探讨了油水比、分散剂用量和交联剂用量对树脂形态和吸液性能的影响。制备的高吸水树脂最佳吸蒸馏水倍率和吸盐水倍率分别为956g/g和137g/g。引入质量分数为9%的粉煤灰后,树脂仍能保持较高的吸水倍率和吸盐水倍率,分别为616.4g/g和66.3g/g。     

聚(丙烯酸-丙烯酰胺)高吸水树脂的制备及性能研究

以环己烷为溶剂,Span80为悬浮稳定剂,丙烯酸(AA)和丙烯酰胺(AM)为共聚单体,过硫酸钾为引发剂,N,N’-亚甲基双丙烯酰胺(NMBA)为交联剂,采用反相悬浮聚合法制备了聚(丙烯酸-丙烯酰胺)(PAA-AM)高吸水树脂,研究了丙烯酸中和度、单体配比、交联剂和引发剂的用量、反应温度等因素对树脂吸液性能的影响。结果表明,最佳条件下制备的树脂吸去离子水和0.9%NaCl水溶液的倍率分别为1282和109g/g。并且在同等条件下,该树脂样品与法国爱森(SNF)产同类产品相比具有较优异的吸水性能和耐盐性。     

耐盐性多元共聚高吸水性树脂的制备及性能研究

采用反相悬浮聚合法,以过硫酸钾为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,通过多元聚合合成了丙烯酸/丙烯酰胺/2-丙烯酰胺基-2-甲基丙磺酸钠/甲基丙烯酸羟丙酯四元共聚高吸水性树脂。探讨了单体组成配比、反应温度、交联剂用量、引发剂用量等共聚反应条件对吸水性能的影响。结果表明,在聚丙烯酸系聚合大分子链上同时引入适当配比的磺酸基、丙烯酰胺基和羟基能产生良好的协同效应,有效提高树脂的耐盐性及吸水性能。所得产品的最高吸蒸馏水率和吸盐水率分别为690g/g和140g/g,热稳定性好。     

纤维素接枝生物可降解高吸水性聚合物的合成工艺及性能研究

以羧甲基纤维素钠、丙烯酸和丙烯酰胺为单体原料,N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸钾作为引发剂,采用反相悬浮法制备羧甲基纤维素钠接枝丙烯酸/丙烯酰胺高吸水性聚合物。研究了高吸水性聚合物的吸液倍率与引发剂、交联剂和反相悬浮体系油水比的定量关系,并探讨了其在不同温度下的保水性能以及在自然条件下和在土壤环境下的降解能力。结果表明:在引发剂和交联剂分别为单体含量的0.85%和0.08%,油水比为4∶1时,该吸水性聚合物吸水倍率达到最大;在较高温度下,聚合物仍具有较好的保水性能;该聚合物在自然条件下和土壤环境中均具有良好的降解性能。     

水溶液法制备高岭土/聚丙烯酸-丙烯酰胺超吸水性树脂的研究

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钠为引发剂,采用水溶液法制备出高岭土复合聚丙烯酸-丙烯酰胺超吸水性树脂,讨论了实验中主要因素对其吸水性能的影响。结果表明:当中和度为80%,高岭土、引发剂和交联剂量分别为丙烯酸单体质量50%、0.3%和0.025%,单体丙烯酰胺与丙烯酸质量比为7:10时所制得复合树脂吸蒸馏水率达960g/g,吸自来水和生理盐水达330g/g和60g/g。     

魔芋粉接枝丙烯酸(钠)超强吸水剂的制备

以过硫酸钾为引发剂,N,N′-亚甲基双丙烯酰胺为交联剂,魔芋粉与丙烯酸(钠)进行接枝共聚反应制备超强吸水剂.探讨了丙烯酸与魔芋粉配比、引发剂用量等因素对吸水性能的影响.结果表明:在丙烯酸/魔芋粉(质量比)为10/1,引发剂用量为0.150g,丙烯酸中和度为80%,反应温度为60℃,交联剂用量为0.050g条件下制得的SAP吸纯净水倍率达750倍,吸自来水倍率279倍,且凝胶强度好.     

丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸-滤渣高吸水性树脂的制备

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾-亚硫酸氢钠为引发剂,丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,采用水溶液聚合法合成了丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸-滤渣高吸水性树脂.考察了交联剂、引发剂、单体的质量比、AA中和度、反应温度、滤渣含量对树脂吸水率的影响.经正交实验制得的高吸水性树脂在24h内吸水达到饱和,吸蒸馏水1397g/g,自来水330g/g,0.225moL/L NaCl溶液79g/g.该树脂具有一定的耐盐性.     

三元共聚高吸水性树脂的合成及研究

采用水溶性引发剂,以环氧氯丙烷为交联剂,用淀粉、部分中和的丙烯酸(钠)、丙烯酰胺为原料,用分步法进行交联接枝共聚,通过系统实验,选择最佳配比,制得吸无离子水3000(g/g),吸0.9％NaCl水溶液140(g/g)的高吸水性树脂。讨论了引发剂、交联剂、丙烯酰胺用量等合成条件与吸水性的关系。     

吸醇树脂的合成和性能研究

以丙烯酸为单体,过硫酸钾为引发剂,Ｎ,Ｎ’－亚甲基双丙烯酰胺为交联剂,环己烷为分散剂,用苯乙烯－Ｎ,Ｎ－二异丙基丙烯酰胺（ＤＩＰＡＭ）共聚物为分散剂,同时加入硝酸镍,进行反相悬浮聚合,制得吸醇性和吸水性树脂,研究了树脂的吸液性能与交联剂用量,引发剂用量,所得树脂最大吸醇率达５７ｇ／ｇ,吸水率达３６ｇ／ｇ。     

杨树叶纤维素接枝丙烯酸系耐盐性高吸水性树脂的制备研究

以过硫酸钾为引发剂,以N,N′-亚甲基双丙烯酰胺为交联剂,在杨树叶预处理的基础上,采用水溶液聚合的方法制备出了杨树叶纤维素接枝丙烯酸和丙烯酰胺单体的高吸水性树脂,探讨了单体用量、两单体质量比、丙烯酸中和度、引发剂用量和交联剂用量等反应条件对吸水率的影响。最优条件下制备出了对蒸馏水和0.9%NaCl溶液的吸水率分别可达486.3g/g和160.2g/g的高吸水性树脂。采用FT-IR对产物进行了表征、分析。     

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.