乙基纤维素基聚MMA-BA复合高吸油树脂的制备及性能

以废弃棉织物所制备的乙基纤维素(EC)为基体,甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为接枝单体,过氧化苯甲酰(BPO)为引发剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂进行接枝共聚制备了一种新型复合高吸油树脂[EC-g-P(MMA-co-BA)]。通过FT-IR、SEM对EC-g-P(MMA-co-BA)进行了表征,并对制备条件、吸油性能和动力学进行了探讨和分析。结果表明,当m(BA)∶m(MMA)=1∶1,ω(BPO)=0.3%,ω(MBA)=0.01%,ω(EC)=0.83%时所制备的树脂吸油性能最好。准二级动力学模型可以较为完整的描述该树脂的吸油过程,平衡时间大约为1.5h,其对4种油性物质的吸油速率大小依次为:甲苯邻二甲苯二氯甲烷三氯甲烷。     

镁铝双金属氧化物复合丙烯酸酯系吸油树脂的合成及吸附性能研究

以硝酸镁、硝酸铝和尿素为原料,并加入十二烷基磺酸钠制备了疏水性镁铝氧化物。以丙烯酸丁酯(BA)、甲基丙烯酸丁酯(BMA)和苯乙烯(St)为单体,聚乙烯醇(PVA)为分散剂,乙酸乙酯为致孔剂,过氧化苯甲酰(BPO)为引发剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,加入一定量疏水性镁铝氧化物,合成镁铝双金属氧化物复合丙烯酸酯系吸油树脂,并对该复合树脂的吸油性能进行了性能测试。结果表明,复合树脂对四氯化碳、三氯甲烷和甲苯的最高吸附倍率分别为42.89、36.29、26.85g/g。对复合树脂吸附四氯化碳的动力学模型拟合结果表明,复合树脂吸油符合准一级动力学模型。复合树脂的热重分析结果表明,复合树脂比原树脂的热稳定性有一定提高。     

速吸型吸油树脂的制备及性能研究

以甲基丙烯酸十二酯( LMA)、苯乙烯( St)和丙烯酸丁酯( BA)为共聚单体,制备速吸型吸油树脂。研究了单体配比等因素对树脂吸油率和吸油速率的影响。结果表明:1、成功制备了三元吸油树脂;2、当St的用量为40%( w),m( BA)∶m( LMA)=1∶2时,制备的三元吸油树脂对3#喷气燃料和甲苯的最大饱和吸油率分别为8.25 g/g、12.77 g/g。     

橡胶基丙烯酸酯系高吸油树脂的制备及性能

以丁苯橡胶(SBR)为基体,甲基丙烯酸十八酯(SMA)和乙酸乙烯酯(VAc)为聚合单体,过氧化苯甲酰(BPO)为引发剂,二乙烯基苯(DVB)为交联剂,在甲苯溶液中通过溶液聚合两步法得到新型改性高吸油树脂(R-OAR)。分别考察了单体配比、SBR、引发剂和交联剂用量作为单一影响因素对油品吸油平衡值进行了探讨,并结合傅里叶变换红外光谱(FT-IR)、热重分析(TGA)和扫描电子显微镜(SEM)对其进行表征。FT-IR表明,SMA、VAc成功接枝到SBR上,共聚形成了R-OAR;TGA表明,R-OAR热稳定性较高吸油树脂(OAR)好,分解温度提高了约50℃;单体配比为1.5∶1,SBR用量为5 g,BPO1和BPO2用量分别为4%和0.6%,交联剂为2%时,吸油平衡值达到最大,对柴油、甲苯、苯、四氯化碳分别为10.1 g/g,19.74 g/g,23.18 g/g,30.49 g/g;SEM表明,树脂中存在有利于提高其吸油能力的类交织状结构和织状间隙。     

聚氯乙烯接枝丙烯酸丁酯型吸油树脂的合成与性能

以轻度脱氯化氯的聚氯乙烯(PVC)、丙烯酸丁酯(BA)、二乙烯基苯(DVB)N原料,采用悬浮溶胀接枝共聚的方法合成一种新型高吸油性树脂。研究了BA含量、DVB用量、过氧化苯甲酰(BPO)用量等因素对其吸油性能的影响。该树脂对含氯的有机溶剂具有较高的吸附性．最高可吸三氯甲烷38g／g,氯苯31g／g。其对甲苯等其它有机溶剂的吸附性能与烷基丙烯酸酯型低交联吸油树脂的吸油性能相当。     

新型多组分聚丙烯酸酯类高吸油树脂微球的合成及性能研究

聚丙烯酸酯类吸油树脂因具有良好的吸油性、保油性而备受关注，目前研究大多集中在块材或粉末上，对微球状树脂的研究较少。微球因其加工更加方便、吸油倍率更高而备受关注。采用悬浮聚合法，通过调节软硬单体比例，维持反应体系稳定性，制备了分散性好的吸油树脂微球。以甲基丙烯酸十八烷基酯(SMA)、丙烯酸丁酯(BA)和苯乙烯(ST)为单体，二乙烯苯(DVB)为交联剂，偶氮二异丁腈(AIBN)为引发剂，环己烷(CYH)为致孔剂，合成P(SMA-co-BA-co-ST)高吸油树脂微球。采用红外光谱(FT-IR)、扫描电镜(SEM)、光学显微镜(OM)、热重分析(TG)等手段对树脂微球进行表征。结果表明：所得树脂微球分散性好、粒径均匀，比表面积大。系统分析了各因素对树脂吸油性能的影响，确定最佳反应条件：m[SMA∶BA]=3∶1、ω(ST)=25%、ω(DVB)=0.2%、ω(AIBN)=1.25%、ω(PVA)=1.25%、ω(CYH)=20%,对CCl₄、CHCl₃、CH₂Cl₂的饱和吸油倍率分别为33.50g/g、3...     

高吸油树脂的合成及回用研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)及丙烯酸异辛酯(EHA)为共聚单体,二甲基丙烯酸乙醇酯( EGDMA)为交联剂,过氧化苯甲酰(BPO)为引发剂,明胶为分散剂,活性磷酸钙(ATCP)为助分散剂,采用悬浮聚合法在3L四口烧瓶中合成了三元共聚高吸油树脂.讨论了吸油时间、单体配比、交联剂用量及引发剂用量对树脂吸油...     

丙烯酸丁酯-苯乙烯共聚乳液型吸油树脂的合成及性能研究

以丙烯酸丁酯(BA)和苯乙烯(St)为单体,二乙烯基苯(DVB)为化学交联剂,采用乳液合成法制备吸油树脂.通过正交实验得到最佳合成配方,即BA∶ St=2∶1,w(二乙烯苯)=2％,w(过硫酸钾)=1％,w(丁苯橡胶)=O％,二甲苯的吸收率达到8.73g/g.同时探索了单体配比、DVB用量、油品种类对树脂吸油性能的影响...     

喷雾干燥法制备微米-纳米复合结构高吸油树脂中空微球

以苯乙烯和甲基丙烯酸十八酯为单体、甲基丙烯酸双环戊二烯酯为交联剂,采用喷雾干燥法制备了高吸油树脂中空微球.表征了高吸油树脂微球的微观形貌,考察了交联剂用量对树脂吸油性能的影响,同时与采用悬浮聚合法制备的树脂的吸油及疏水性能进行了对比.结果发现,采用喷雾干燥法制备的微球是由许多纳米粒子聚集而成的中空微米级微球;随着交联剂用量的增加,树脂吸油量呈先增加后减少的趋势,到达饱和吸油率所需时间减少;交联剂用量为3%(质量分数)的树脂吸油性能达到最好,对甲苯、三氯甲烷的饱和吸油率分别为20.78及28.32g/g,4h内对甲苯的吸收基本饱和;而采用悬浮聚合所制备的高吸油树脂,对甲苯和三氯甲烷的饱和吸油率分别为11.26、24.18g/g,12h吸油达到饱和;喷雾干燥及悬浮聚合制备的树脂与水的接触角分别为111.14与85.39°,表面能分别为38.10与42.85mJ/m2,采用喷雾干燥制备的高吸油树脂中空微球表现出较好的疏水性.     

聚甲基丙烯酸十二酯的合成及吸油性能

以甲基丙烯酸十二酯(LMA)为单体,采用悬浮聚合法合成了聚甲基丙烯酸十二酯(PLMA),研究了该树脂对柴油、汽油、甲苯和四氯化碳的吸油性能。结果表明,树脂的吸油率随着时间的延长不断增大,最后达到最大吸油率Qmax,CCl4的Qmax最大,为14.596 g/g,达到Qmax的时间约为110 min;柴油的的Qmax最小,为4.174 g/g,而吸油速率则随着时间的延长呈现出不断降低的趋势。树脂对CCl4、甲苯和汽油的保油率不到90%,对柴油的保油率达到90%以上。树脂的缓释保油率与油品的种类关系较大,树脂对甲苯和四氯化碳的缓释能力较大。     

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.