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。     

AMA与MMA嵌段共聚物的合成与鉴定

探讨了聚合时间对α－甲基丙烯酸烯丙酯（ＡＭＡ）α位双键选择性阴离子聚合的影响，合成了ＡＭＡ、与ＭＭＡ的双嵌段及三嵌段共聚物。结果发现，随聚合时间的延长，单体转化率提高、分子量增大、分子量分布变窄。嵌段共聚物的合成中，ＭＭＡ首先聚合时，引发效率较高；当ＡＭＡ首先聚合时，分子量分布较窄。ＧＰＣ、ＮＭＲ、ＤＳＣ及ＴＧ测试结果表明，所得共聚物的具有较窄的分子量分布、组成比与设计值一致、ＡＭＡ段的每个重复单     

苯乙烯-甲基丙烯酸共聚物的合成及性能的研究

采用悬浮聚合法合成了不同分子量、不同甲基丙烯酸（MAA）含量的系列苯乙烯－甲基丙烯酸共聚物（PSMAA）。用DSC、拉伸、冲击、熔体流变试验等对共聚物的力学和加工性能进行了研究,结果表明：（1）随着MAA含量的增加,PSMAA共聚物的Tg升高,热稳定性增加。（2）共聚物的拉伸、冲击强度均随MAA含量和分子量的增加而升高。（3）MAA含量在8mol%以内,分子量（Mn^-)在20万左右;MAA含量在18mol％以内,Mn^-在10万左右的PSMAA共聚物的加工性能较好。     

聚N-异丙基丙烯酰胺共聚物的动态光散射研究

以双键类单体N-异丙基丙烯酰胺(NIPAAm)、甲基丙烯酸(3-三甲氧基硅)丙酯(MPS)和甲基丙烯酸羟丙酯(HPMA)为原料,通过自由基聚合法制备了温敏性PNMH共聚物.利用动态光散射仪测试了共聚物在不同水溶液中的水力学直径,考查了温度、pH及盐类溶质对共聚物尺寸、构型及其最低临界溶液温度(LCST)的影响,同时分析...     

甲基丙烯酸环氧丙酯-b-甲基丙烯酸十二氟庚酯嵌段共聚物的合成及在疏水涂层中的应用

采用连续再生催化剂原子转移自由基聚合(ICAR ATRP)合成了甲基丙烯酸环氧丙酯-b-甲基丙烯酸十二氟庚酯嵌段共聚物(PGMA-b-PDFHMA)。然后将嵌段共聚物与纳米二氧化钛(Ti O2)复合制备疏水涂层。通过凝胶渗透色谱、核磁共振仪、接触角、扫描电子显微镜等对嵌段共聚物及涂层进行了研究与表征。研究结果表明,采用ICAR ATRP法成功制备了甲基丙烯酸环氧丙酯-b-甲基丙烯酸十二氟庚酯嵌段共聚物。嵌段共聚物结构及嵌段共聚物与纳米粒子的比例对涂层疏水性有显著影响。当含氟嵌段共聚物的链段摩尔比为1∶0.10,含氟嵌段共聚物与Ti O2质量比为0.5/1~10/1时,含氟嵌段共聚物接枝纳米Ti O2混合物制备的涂层表面的接触角可达150°。嵌段共聚物的含氟链段长度和涂层表面粗糙结构的差异是影响涂层疏水性的主要原因。     

两亲性透皮控释新辅料结构与性能的研究

甲基丙烯酸β－羧乙酯（ＨＥＭＡ）和丙烯酸长链烷基酯（ＲＡ）的自由基共聚合是８０℃二氧六环为溶剂,使用过氧化苯甲酰（ＢＰＯ）为引发剂聚合而成,采用了ＩＲ、ＤＳＣ、ＳＥＭ等手段研究了该共聚物的结构与性能的关系。实验结果表明该共聚物的吸水性随共聚物中亲水基的增加而增加。     

MBHD四元共聚物乳液的合成与表征

合成了含有甲基丙烯酸羟乙酯（ＨＥＭＡ）和甲基丙烯酸二甲氨基乙酯（ＤＭＡＥＭＡ）的四元共聚物乳液（ＭＢＨＤ乳液）,研究了乳化单体加入方式、聚合温度、非离子和阴离子乳化剂配比和用量及ＨＥＭＡ和ＤＭＡＥＭＡ用量对共聚物乳液的粒径及其分布、粘度和表面张力的影响。间歇聚合过程由于水相成核较多而使所得乳液的粒径较小,粒径分布较宽、乳液粘度和表面张力较大,官能团单体ＨＥＭＡ和ＤＭＡＥＭＡ用量增大使共聚物乳液的表     

甲基丙烯酸酯系共聚吸附功能纤维的制备与表征

以过氧化苯甲酰（BPO）为引发剂,采用悬浮聚合法制备了含有质量比为10%甲基丙烯酸β羟乙酯,0%～30%丙烯腈的甲基丙烯酸正丁酯/甲基丙烯酸β羟乙酯/丙烯腈P（BMA/HEMA/AN）三元共聚物。同时采用冻胶纺丝技术制备了对低分子有机液体具有吸附功能的纤维。通过红外光谱（FT-IR）、扫描电镜（SEM）等研究了共聚物的...     

甲基丙烯酸环氧丙酯与1—（2—叔丁基过氧异丙基）—3异丙烯 …

通过甲基丙烯酸环丙酯与１－（２－叔丁基过氧异丙基）－３异丙烯基苯的共聚，得到了带过氧和环氧两种侧基的共聚物，由该共聚物与聚乙烯熔融共混可得到带环氧基团的接枝聚乙烯，该技枝聚乙烯ＰＢＴ熔融共混时可就了生成具有增容作用的特殊的聚乙烯－ＰＢＴ接枝共聚物。     

丙烯酸氟烷基酯乳液聚合的研究

以甲基丙烯酸氟烷基酯(Zonyl TM)、甲基丙烯酸甲酯、丙烯酸正丁酯为原料,采用氧化-还原引发体系,以十二烷基硫酸钠和全氟辛酸铵(1∶1)为乳化剂,经超声波预乳化后进行聚合,制备了一系列高氟单体含量的三元共聚物乳液,系统研究了聚合条件对乳液稳定性等影响.考察了氟元素含量对共聚物表面性能的影响,含氟共聚物对水和对油的接触角最高可分别为116°和77.5°.     

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.