一步法合成松香改怀酚醛树脂

探讨了一步法合成松香改性酚醛树脂的反应机理，确定了最佳原料组成及合成工艺，由此制备出溶解粘度和矿油容纳度的松香改性酚醛树脂，是一种性能优异的高级胶印油墨连接料。     

聚合松香改性酚醛树脂的合成

制备了二聚体含量为23.5%～90%的聚合松香,用于酚醛树脂的改性.研究了聚合松香中二聚体含量、酚醛浆及顺酐用量等因素对制备改性酚醛树脂的影响,揭示了这些因素对树脂产品的软化点、黏度及正庚烷值等指标的影响规律.当酚醛浆用量为聚合松香的25%,聚合松香的二聚体含量为50%～65%,顺酐用量为聚合松香的2%～3%时,得到了黏度为6000 mPa·s/35 ℃～20000 mPa·s/35 ℃,软化点为180 ℃～190 ℃,正庚烷值为8 mL/3 g～12 mL/3 g的聚合松香改性酚醛树脂产品,可用于高档胶印油墨的生产.     

平版胶印油墨用松香改性酚醛树脂合成工艺及其发展

松香改性酚醛树脂是以松香，烷基酚，多元醇及甲醛等为主要成分，经一定的缩合聚合反应得到高分子量，低酸价的树脂。由于其独特的蜂窝状结构特征，因此能与颜料良好润湿，与凝胶剂适当反应可以得到有一定粘弹性的连接料而被广泛应用于平版油墨。而实验结果表明树脂的性能在很大程度上取决于烷基酚的类型，目前松香改性酚醛树脂中使用的酚为叔丁酚，辛基酚，壬基酚，十二烷基酚等，还有油溶性较差的苯酚，双酚A。     

梓油改性酚醛树脂的合成及结构分析

用我国湖北省产的梓油，合成了改性酚醛树脂，并对反应机理和树脂结构进行了分析。结果表明，当梓油含量不苯酚含量为３０－６０％时，改性酚醛树脂的性能最好。在改性酚醛树脂交联固化过程中所形成的ＩＰＮ结构，提高了酚醛树脂的韧性的耐热性。     

不同烷基苯酚对松香改性酚醛树脂性能的影响

分别选用十二烷基苯酚、壬基苯酚、对特辛基苯酚和对叔丁基苯酚四种烷基酚单体为原料,合成了四种不同的松香改性酚醛树脂。通过黏度、溶解性等常规性能分析以及红外光谱(FT-IR)、凝胶渗透色谱(GPC)和流变等表征方法,探讨了不同烷基苯酚对松香改性酚醛树脂结构与性能的影响。结果表明,在相同工艺条件下,不同烷基酚单体对树脂的主体结构及热稳定性影响不大,但对树脂的其它性能影响较大;随着烷基酚碳链长度的增加,树脂在亚麻油中的溶解稳定性提高,但体系的黏度降低;黏度随剪切速率与温度变化的敏感性减弱。可见,选用合适的烷基苯酚能提高树脂的综合性能。     

耐热,阻燃酚醛树脂的合成

本文运用羟甲基膦酸酯系列化合物，对酚醛树脂进行改性。探讨了合成中反应条件对反应程度的影响，并对改性树脂的阻燃性和耐热性能进行了初步的研究。结果表明：以羟甲基膦 酯化合物为阻燃改性剂合成的酚醛树脂，具有醇溶性、阻燃性好，耐热性强。     

离子液体改性酚醛树脂的制备及性能研究

合成了甲基丙烯酸二甲氨基乙酯马来酸盐离子液体(DMAEMA-MA),通过共混法制备了DMAEMA-MA改性酚醛树脂和DMAEMA-MA改性酚醛树脂/石墨烯复合材料.探讨了DMAEMA-MA含量对DMAEMA-MA改性酚醛树脂热稳定性、力学性能及导电性能的影响.结果 表明:DMAEMA-MA的添加显著提高了酚醛树脂的冲击...     

腰果酚改性酚醛树脂的研究进展

随着现代社会的快速发展，对酚醛树脂的韧性、耐热性、耐水性等方面有了更高的要求，以腰果酚部分替代苯酚后合成腰果酚改性的酚醛树脂，不仅能够提高其韧性及耐热性，还能大大降低生成产成本，绿色环保。因此，腰果酚用作酚醛树脂的生物质改性剂具有较强的应用价值。介绍了腰果酚的结构与性质，简述了腰果酚改性酚醛树脂的制备方法、改性方法，及其在摩擦材料、模塑料、酚醛泡沫、涂料、复合材料等领域的应用。     

集成电路封装用环氧模塑料的绿色阻燃

合成了三聚氰胺改性含氮酚醛树脂,以邻甲酚醛环氧树脂为基体树脂,以自制的改性酚醛树脂为固化剂和阻燃剂,对集成电路封装用环氧模塑料绿色阻燃配方及工艺进行了研究。结果表明自制的改性酚醛树脂固化能力好,阻燃效果好。     

松香树脂酸合成新材料的研究进展

综述了松香树脂酸合成新材料的最新研究进展,分别详细介绍了松香树脂酸基于羧基的改性、共轭双键的改性、羧基和芳环的共改性以及羧基和共轭双键的共改性及其衍生物的应用情况,并展望了该领域发展趋势及前景。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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 Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.