用多官能团单体敏化氯化丁基橡胶的辐射交联反应

观察到丁基橡胶这一典型辐射降解型高聚物的氯化产物在电子束辐照下能发生交联反应，测得其凝胶化剂量为３．８ｋＧｙ。考究了６种多官能团单体对ＣＩＩＲ的敏化效应，以期在低剂量下达到较高的交联程度；发现三羟甲基丙烷三甲基丙烯酸酯能够有癣地提高ＣＩＩＲ的凝胶含量和交联密度。添加ＴＭＰＴ的ＣＩＩＲ经辐照后其拉伸强度几乎随ＴＭＰＴ含量成正比地线性提高。     

马来酸酐-苯乙烯多单体熔融接枝EVA的研究

用单螺杆挤出机研究了马来酸酐（MAH）－苯乙烯（St)多组分单体熔融接枝EVA的反应,考察了温度、引发剂用量、MAH和St用量对接枝率及凝胶率的影响。结果表明：MAH接枝率随DCP用量、St用量的增加、反应温度的降低有最大值;当EVA／MAH／St/DCP质量比为100：4：4：0.4时,MAH接枝率最大,而凝胶率最小;以St作共单体能够显著提高MAH的接枝率,抑制体系交联;St和MAH的相互作用和共聚反应生成的SMA共聚物在接枝反应中起重要作用。     

不饱和型降冰片烯-三元乙丙橡胶的交联机理

通过原位升温红外光谱结合差示扫描量热(DSC)测试,研究了ENB-EPDM的交联反应过程。从外扰相关移动窗口二位相关红外(PCMW2D)图谱和DSC曲线分析中可以观察到,交联反应的最大速率出现在178℃处。利用PCMW2D得到交联过程的反应温度区域在160～192℃。为了获得ENB-EPDM在交联反应过程中具体的交联机理,在广义二维相关分析中对相应官能团对应的波数进行分析。从各个官能团运动的先后次序上能够将这一交联过程划分为4个具体步骤,同时,环上双键的变化作为与交联过程平行的1个过程:过氧化二异丙苯(DCP)开始分解并释放出自由基;在主链亚甲基上的1个氢原子受到由DCP分解而来的自由基的进攻,从而形成一部分甲基自由基;由DCP分解而来的自由基在侧链甲基上进行自由基加成反应,生成新的链自由基;不同分子链之间的2个链自由基相互偶合生成新的共价键完成整个交联反应过程。与此同时,第3单体上的-CH-CH-结构在初始的游离过氧化自由基的诱发下,在热作用下脱氢形成双键,并在更高的温度下打开双键进行交联。     

过氧化物交联改性聚丁二酸丁二醇酯薄膜的抗撕裂性

用过氧化二异丙苯(DCP)引发丁二酸丁二醇酯(PBS)部分交联反应来改性其抗撕裂性。结果表明,PBS的凝胶含量随DCP含量增加,当DCP的质量分数达0.6%时,凝胶量达到了13.1%。纯PBS和部分交联PBS受热出现双熔融峰,分别对应原始片晶熔融和再结晶增厚片晶熔融;交联后结晶度减小、晶粒较小造成吸热峰也变小;峰位向低温偏移。在一定范围内,交联度增大,纵横向的屈服、断裂的强度及伸长率随之增大;0.6%DCP交联PBS膜的薄膜横向撕裂强度由298.5 N/mm增大到407.5 N/mm,提高36.5%;纵向撕裂强度提高29%。交联后PBS的延展性变好,不会轻易断裂。     

LLDPE硅烷接枝交联反应的研究

选用线性低密度聚乙烯(LLDPE),接枝单体乙烯基三甲氧基硅烷(VTMOS),以过氧化二异丙苯(DCP)为引发剂,采用熔融挤出法对LLDPE进行硅烷接枝,然后在催化剂二月桂酸二丁基锡(DBTDL)存在下进行水解交联反应.研究了凝胶含量随水解时间的变化关系.通过改变VTMOS、EGP用量,系统地考察了对交联LLDPE的凝胶含量、力学性能以及结晶性能的影响.结果表明:凝胶含量在水解初期随时间的增长而快速增加,10h后凝胶含量趋于平缓.硅烷接枝交联LLDPE,由于其三维网络结构的存在,使得力学性能显著提高,其熔点和结晶度则都有不同程度的降低.     

三官能团交联剂改性苯乙烯-丙烯酸乳液的制备及其防腐性能研究

分别考察了三羟甲基丙烷-三(3-吖丙啶基丙酸酯)(XR-100)、三烯丙基异氰脲酸酯(TAIC)、三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)3种三官能团交联剂对苯乙烯-丙烯酸乳液粒径、相对分子质量、交联度、玻璃化转变温度、耐水性和耐腐蚀性的影响。结果表明:苯乙烯-丙烯酸乳液的相对分子质量、交联度和耐水性均随着3种交联剂用量增加而提高;以双键自由基聚合交联的TMPTMA和TAIC交联剂可以显著地提升苯乙烯-丙烯酸乳液的玻璃化转变温度及耐腐蚀性能;以官能团缩聚交联的XR-100交联剂无法形成致密网络结构且消耗羧基,导致涂层附着力下降,不适用于苯乙烯-丙烯酸乳液防腐体系。     

饱和型乙烯-丁烯弹性体的交联机理

乙烯-丁烯共聚物弹性体(POE)通常采用过氧化二异丙苯(DCP)进行交联反应,但是该交联反应的具体机理尚不明确。文中通过原位升温红外光谱结合外扰相关移动窗口二维相关红外(PCMW2D)和广义二维相关红外分析对POE的DCP交联机理进行了分析。在差示扫描量热分析(DSC)中,POE交联反应过程的温度区域能够在曲线中得到佐证。从PCMW2D图谱分析和DSC曲线中可以看出,交联反应的最大速率出现在170～188℃处。为了获得交联反应过程中具体的交联机理,在广义二维相关分析中对相应官能团对应的波数进行分析。从各个官能团运动的先后次序上能够将这一交联过程划分为4个具体步骤:DCP开始分解并释放出自由基;由DCP分解而来的自由基在主链亚甲基上进行自由基加成反应,生成新的链自由基;在侧链甲基上的1个氢原子受到由DCP分解而来的自由基的进攻,从而形成一部分甲基自由基;不同分子链之间的2个链自由基相互偶合生成新的共价键完成整个交联反应过程。     

聚氯乙烯/聚苯乙烯共混物在过氧化物作用下的交联和降解问题

通过流变实验和共混物中聚苯乙烯的分子量测定发现，在用过氧化二异丙苯（DCP）对聚氯乙烯（PVC）/聚苯乙烯（PS）/丁腈橡胶（NBR）（质量比(46/46/8）共混体系实施原位交联时，PS在自由基引发下发生降解，且随着DCP含量的增加，其降解程度随之增加，在适中的DCP含量(0.15%）时，共混物的冲击强度最佳，在上述体系中加入苯乙烯时，苯乙烯单体在均聚的同时还与NBR和PVC发生接枝反应，从而起增容作用，同时在一定程度上抑制了共混物中PS的降解。     

交联型聚L-丙交酯的制备和性质研究

通过含活性端基聚L-丙交酯大分子单体在不同条件下的交联反应,制备了一系列交联型聚L-丙交酯。发现端基数对交联产物的性质有明显影响。溶解试验、凝胶含量测定表明,端基数目较多的大分子单体的交联产物凝胶含量较高热重分析（TGA）、降解试验和拉伸试验表明,交联产物的耐热性和拉伸强度提高,降解速率减慢,其变化趋势和交联样品的凝胶含量有关。     

酚醛树脂丙烯酸酯季铵盐感光性能的研究

通过凝胶生成率的测定,研究了紫外光引发剂：安息香（NB）、安息香乙醚（BE）、2,2－二乙氧基苯乙酮（DEAP）、二苯甲酮（BP）、2－丙基硫杂蒽酮（ITX）;交联型稀释性单体：二乙二醇二丙烯酸酯（DEDA）三乙二醇二丙烯酸酯（TEDA）、二乙二醇二甲基丙烯酸酯（DEDMA）、三乙二醇二甲基丙烯酸酯（TEDMA）、三羟甲基丙烷三丙烯酸酯（TMPTA）、三羟甲基丙烷三甲基丙烯酸酯（TMPTMA）;胺增效剂：乙基－4（二甲基氨基）苯甲酸酯（DEAB）等对水溶性酚醛树脂丙烯酸酯季铵盐（PreP)感光性能的影响。结果表明,ITX的光引发效率最高;交联型黧性单体中活性基团越多,反应活性越高,分子量越大,反应活性越差;二乙醇类与PreP的相容性比三羟甲基烃类的要好;胺增效剂能提高ITX的引发效率;PreP/DEDA=1/0.6(g/g),ITX为0.025mmol/g,DEAB为感光组分的2％,曝光60s,凝胶生成率可达到67.6%,延长曝光时间凝胶生成率增加。     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.     

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.