高吸水性三元共聚树脂的合成及性能研究

采用反相悬浮聚合法合成了丙烯酸钠－丙烯酰胺－甲基丙烯酸羟乙酯三元共聚物高吸水性树脂,研究了共聚物吸水性能与共聚物组成,交联剂用量,反应体系中油相水相比之间的关系;分析了共聚物吸水树脂的吸水溶胀动力学。实验结果表明,非离子性单体的引入,显著改善了共聚物吸水树脂的抗盐性能,土壤中添加０．２％的三元共聚树脂即可明显提高土壤的保水性能。     

紫外光激活自修复聚合物的合成与性能研究

在石油醚和NaOH溶液两相体系中,以二硫化碳、丙酮、氯仿为原料,季铵盐为相转移催化剂,合成出s,s′-二(a,a′-甲基-a′′-乙酸)三硫代碳酸酯(TTC1)。以偶氮二甲酸二乙酯、三苯基膦为催化剂,TTC1与甲基丙烯酸羟乙酯酯化反应合成TTC2。TTC2与丙烯酸丁酯、丙烯酸乙酯分别进行活性自由基聚合后得到三硫代碳酸酯类聚合物材料PBA-L和PEA-L。同时以1,6-己二醇二丙烯酸酯为交联剂分别对丙烯酸丁酯、丙烯酸乙酯进行了自由基聚合,得到聚丙烯酸丁酯(PBA)和聚丙烯酸乙酯(PEA)。用红外、紫外、核磁、元素分析、高效液相色谱、DSC等对TTC1、TTC2、PBA-L、PEA-L进行了表征。结果表明,普通自由基聚合的材料PBA、PEA无自修复功能,而通过活性自由基聚合的材料PBA-L、PEA-L具备多次自修复功能。     

MMA-BA-DMAEMA三元共聚物胶乳的电解质稳定性

采用间歇及半连续乳液聚合方式,合成得到了甲基丙烯酸甲酸酯－丙烯酸丁酯－甲基丙烯酸二氨基乙酯三元共聚物胶乳,系统研究了乳化剂类型,复合配比及用量,聚合温度,聚合方式和官团单体含量对共聚物乳液耐电解质稳定性的影响。     

甲基丙烯酸羟乙酯/丙烯酸甲酯接枝聚合炭黑的制备研究

考察了甲基丙烯酸羟乙酯/丙烯酸甲酯接枝聚合炭黑的适宜制备条件和影响因素。通过红外光谱(FT-IR)、热失重分析(TGA)考察了接枝炭黑的表面结构和接枝情况,研究了接枝炭黑在水溶液中的吸光度。结果表明:用丙烯酸甲酯/甲基丙烯酸羟乙酯接枝改性后的炭黑在水溶液中具有良好的分散稳定性。     

PEG/HEMA水凝胶复合支架的制备及其溶胀性能

以偶氮二异丁腈(AIBN)为引发剂,N,N'-亚甲基双丙烯酰胺(BIS)为交联剂,采用自由基聚合法合成了聚乙二醇(PEG)/甲基丙烯酸β-羟乙酯(HEMA)复合凝胶.采用冷冻干燥法制备凝胶支架,结果表明,凝胶支架具有多孔结构,为水分子的进出提供了路径和代谢物通道;随着交联剂用量的增大,水凝胶的平衡含水量降低;凝胶的平衡含水量随着温度的升高而下降,离子强度的增加使水凝胶的溶胀度降低.     

丙烯酸酯与甲基丙烯酸酯的共聚及性能研究

采用悬浮聚合法，以丙烯酸－２－乙基－己酯与甲基丙烯酸十二酯为单体，合成了共聚型高吸油性树脂。研究了共聚单体的配比、交联剂用量、引发剂用量诸因素对高吸油性树脂的性能影响。制得的树脂可以吸其自身质量的１１．８倍的煤油、１４．７倍的苯、６．５倍的泵油。     

氟化羟基丙烯酸酯树脂的制备及聚合动力学

以甲基丙烯酸甲酯、丙烯酸丁酯、甲基丙烯酸β-羟乙酯、甲基丙烯酸十二氟庚酯为原料,通过自由基溶液聚合,制备了氟化羟基丙烯酸酯树脂。考察了聚合温度、引发剂物质的量浓度、含氟单体及含羟基单体物质的量浓度对聚合速率的影响以及涂膜的疏水性。结果表明,当含氟单体用量为20%时,涂膜的水接触角为101°,聚合反应的表观活化能为88....     

聚氨酯丙烯酸酯的合成及其对紫外固化医用导电压敏胶性能的影响

以2,4-甲苯二异氰酸酯和不同相对分子质量的聚丙二醇(PPG)为原料,有机铋为催化剂合成了含异氰酸酯端基的聚氨酯,然后用甲基丙烯酸羟乙酯封端得到聚氨酯丙烯酸酯。以聚氨酯丙烯酸酯为大分子交联剂,N,N-亚甲基双丙烯酰胺为小分子交联剂,丙烯酸和丙烯酰胺-2-甲基丙磺酸为单体,用紫外光引发剂引发聚合,在氯化钾(KCl)溶液中固化制得导电压敏胶。采用傅里叶变换红外光谱仪、核磁共振氢谱仪和凝胶渗透色谱仪对聚氨酯丙烯酸酯进行表征。对导电压敏胶的剥离力进行测试发现,当使用质量分数为2.4%的PPG2000软段聚氨酯丙烯酸酯为大分子交联剂时,所得到的导电压敏胶具有最大的剥离力,其导电性能随着KCl含量的增加而增强。生物相容性测试表明该导电压敏胶透气性好,对皮肤没有刺激性,具有临床应用的潜力。     

硼酸三乙醇胺酯的合成及表征

为了解决硼酸铝晶须及含硼类无机物的表面处理问题,通过给硼原子提供配位电子以改善硼酸酯水解稳定性的思路出发,进行分子结构设计,合成了具有氨基反应活性基团的硼酸酯偶联剂,用傅立叶变换红外光谱对硼酸酯进行了结构表征,研究了原料配比、带水剂用量、合成工艺对硼酸酯收率及反应速率的影响,并通过实验确定了最佳配方及工艺。同时对硼酸酯的物理性能、溶解性及水解稳定性进行了表征,结果表明．合成的硼酸酯偶联剂由于具有氮、硼内配位作用,表现出优良的水解稳定性和良好的溶解性,很好地解决了硼酸酯水解稳定性差的问题。     

新型共聚水凝胶P(HEMA-co-EMA)交联网络的结构参数

以大分子单体甲基丙烯酸环氧酯（EMA）与亲水性单体甲基丙烯酸-β-羟乙酯（HEMA）为原料,双甲基丙烯酸乙二醇酯（EDMA）为交联剂,采用本体聚合方法合成了一系列新型水凝胶.从宏观方面研究了EMA含量、温度对水凝胶溶胀、拉伸性能的影响,进而研究了水凝胶的交联网络结构参数.EMA含量的增大加强了水凝胶内部疏水基团间的相互作用,使平衡含水EWC降低,聚合物体积分数φ2增大,拉伸强度、杨氏模量、有效交联密度υe以及聚合物-水相互作用参数χ也随之增大,网链分子量Mc减小.当温度由275 K升至304 K,水凝胶样品EMA25/HEMA75的EWC值下降,φ2值和χ值增大.     

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.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

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.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

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.