高支化环三磷腈型苯并噁嗪的合成表征及性能

以自制的六(4-羟基苯氧基)环三磷腈(I)、苯胺、甲醛为原料,甲苯为溶剂合成了高支化环三磷腈型苯并噁嗪(II),收率68.9%。采用傅里叶变换红外光谱、核磁氢谱、差示扫描量热法、热重分析、极限氧指数(LOI)和水平-垂直燃烧试验对(II)及其固化物(III)的结构和性能进行了表征,并对比了其与传统苯并噁嗪的热性能与阻燃性能。结果表明,(II)的开环聚合起始温度为186.0℃,峰值温度为235.4℃,具有比传统苯并噁嗪更低的开环聚合起始温度;(III)的5%和10%热失重温度分别为344.1℃和392.7℃,800℃残炭率为64.97%,LOI值可达43.5%,UL-94等级为V-0,具有比传统苯并噁嗪更为优异的热稳定性和阻燃性,可应用于阻燃要求较高的场合。     

芴基苯并噁嗪的合成表征及热性能

合成了9,9’-二(3-苯基-2,4-二氢-1,3-苯并噁嗪)芴(简称BFA)、9,9’-二(3-烯丙基-2,4-二氢-1,3-苯并噁嗪)芴(BFB)和大分子苯并噁嗪单体(BFC)。分别用核磁共振仪(1H-NMR)和红外光谱仪(FT-IR)对它们的结构进行了鉴定。差示扫描量热(DSC)对三种芴基苯并噁嗪的固化反应研究结果表明,它们的固化反应发生在180℃～280℃之间。三种单体的固化物都表现出很高的玻璃化转变温度,其中BFB的固化物的玻璃化温度已经超过300℃,BFA和BFC的玻璃化温度也分别达到202℃和263℃。它们在N2氛围中5%分解温度分别达到325℃、331℃和359℃,体现出较好的热稳定性。     

聚酰胺650对苯并噁嗪开环聚合和固化物性能的影响

制备了聚酰胺650(O-PA)/苯并噁嗪混合体系并测试凝胶化时间、差示扫描量热分析(DSC)和傅里叶变换红外光谱(FTIR),以研究O-PA对苯并噁嗪开环聚合和韧性的影响。结果表明,O-PA能促进苯并噁嗪的开环聚合反应,使其凝胶化时间、开环聚合的起始和峰值温度明显降低,但是不影响苯并噁嗪开环聚合过程中的结构演变和聚苯并噁嗪的化学结构。O-PA的引入使聚苯并噁嗪的韧性明显提高,但是热稳定性有所降低。结果表明,聚酰胺650是一类良好的苯并噁嗪催化剂。     

磷钨酸对苯并■嗪开环聚合历程的影响

在室温下首先制备了磷钨酸/苯酚-苯胺型苯并■嗪(Pa)混合体系,然后通过傅里叶变换红外光谱、核磁共振氢谱、差示扫描量热分析研究了磷钨酸(PWA)对Pa开环聚合过程的影响。测试结果表明,由于磷钨酸中氢离子、钨原子与Pa中氧原子的相互作用,不仅使得Pa开环聚合起始温度和峰值温度随磷钨酸的引入而明显降低,甚至在室温下也可促使Pa开环聚合。通过Kissinger和Ozawa法对苯并■嗪固化动力学进行了研究,结果表明Pa开环聚合反应活化能随磷钨酸的引入而降低,进一步证明磷钨酸对苯并■嗪开环聚合有促进作用。此外,磷钨酸还使得Pa开环聚合过程中形成的碳正离子中间体与苯胺对位反应的几率增加,形成了更多的1,4-二取代芳胺结构,抑制了热降解过程中苯胺结构的挥发。以对甲酚-苯胺型苯并■嗪为模型的GPC测试表明,磷钨酸还可使聚苯并■嗪的相对分子质量有所增加。另外,热重分析结果表明Pa聚合物的热稳定性随磷钨酸的加入而增加。     

苯并噁嗪树脂的研究与应用进展

3,4-二氢-3-取代基-2H-1,3-苯并噁嗪(简称苯并噁嗪),是一类新型的高性能热固性树脂,在加热和(或)催化剂的作用下发生开环聚合,生成含氮且类似酚醛树脂的网状结构,人们将这种新型树脂称作开环聚合酚醛树脂.自上世纪九十年代初以来,有关苯并噁嗪的研究工作取得了快速发展.本文较系统概述了国内外在苯并噁嗪中间体的合成、固化反应、结构与性能关系、应用开发等方面取得的进展,侧重介绍了四川大学在苯并噁嗪研究和应用方面取得的成果.     

环三磷腈基苯并噁嗪的合成及热性能研究

为提高苯并噁嗪树脂的耐高温性能,以水杨醛、对氨基苯酚、环三磷腈衍生物为原料通过多步反应制备了环三磷腈基苯并噁嗪单体(CPBOZ),通过核磁共振(1 H-NMR、31 P-NMR)和傅里叶红外光谱(FT-IR)对所合成化合物的结构进行了表征;利用FT-IR和热重分析(TGA)考察了苯并噁嗪的固化行为及树脂的热稳定性。结果显示:环三磷腈结构的引入,显著提高了相应苯并噁嗪树脂的耐热性,其固化后失重率为5%和失重率为10%时的温度分别达到了365℃和397℃;在900℃(N2)时的失重率达到了48.2%,比普通苯并噁嗪树脂提高了约65.64%。     

可聚合8-羟基喹啉衍生物的合成及高分子化

5氯-甲基-8-羟基喹啉与烯丙醇反应,得到5-(烯丙氧)甲基-8-羟基喹啉可聚合单体,进一步与苯乙烯聚合,得到含8羟-基喹啉基团的高分子。将所得的聚合物与铝离子配位得到高分子配合物(最大发射波长为512 nm)。利用红外光谱、紫外光谱、核磁共振和原子力显微镜(AFM)对配体和配合物的结构进行了表征,利用荧光光谱研究了配合物的光致发光性能。     

含马来酰亚胺和烯丙基醚的苯并(口恶)嗪的合成与性能

合成了3-(4-烯丙氧基)苯基-3,4-二氢-6-(N-马来酰亚胺)-1,3-苯并噁嗪(AMB),用FT-IR、1H-NMR和EA对其结构进行了表征。与传统的3-苯基-3,4-二氢-(N-马来酰亚胺)-1,3-苯并噁嗪(MIB)相比,AMB的分子结构中多了一个烯丙基醚基团。AMB可溶于丙酮、甲醇、氯仿、四氢呋喃等普通有机溶剂,熔点115℃。用DSC和TGA对AMB和MIB的热聚合行为进行了比较,发现烯丙基醚官能团引入后的AMB熔点更低;于氮气条件下,150℃热处理AMB,可大幅度地降低热处理产物的再次热聚合温度,从而使其在相对低的温度下(150℃~200℃)得到充分的固化;AMB固化产物的热稳定性比MIB更好,5%热失重温度(T5)从375℃上升到449℃,800℃残炭率从56%上升到65%。     

耐高温聚苯腈树脂的制备及性能

以芳香二酚(间苯二酚、2,7-二羟基萘、1,6-二羟基萘)、2,6-二氯苯腈和4-硝基邻苯二甲腈为主要原料制备了6种耐高温低熔点型苯腈单体,并利用4,4’-二氨基二苯醚引发聚合。采用红外光谱、核磁共振、差示扫描量热、热重分析、动态机械分析表征了单体和聚合物的结构及性能。结果表明,所合成的苯腈单体产物纯净,熔点在90℃~116℃,加工温度窗口为125℃~155℃。所制备聚苯腈树脂的起始分解温度(Tid)都高于460℃,有限氧指数(LOI)均高于47,表现出了良好的加工性、高阻燃性、优异的热稳定性及高玻璃化转变温度(>380℃)。     

丙烯酸铽配合物及其聚合物的制备和性能研究

目的 研究小分子配合物5-丁氧甲基-8-羟基喹啉丙烯酸铽及其与苯乙烯聚合的高分子配合物的发光性能和热性能,并探讨聚合时间对高分子配合物性能的影响。方法 通过氯甲化反应和取代反应合成5-丁氧甲基-8-羟基喹啉（BTMQ）,并以BTMQ和丙烯酸（HAA）为配体合成5-丁氧甲基-8-羟基喹啉丙烯酸铽（Tb(BTMQ)2HAA）。然后,用小分子配合物和苯乙烯聚合得高分子配合物p(St-co-Tb(BTMQ)2HAA。通过热重（TG）分析和荧光光谱测试研究配合物的热性能和发光性能。结果 小分子配合物的起始分解温度和荧光强度分别为262 ℃和222;聚合反应为8 h时,高分子配合物的起始分解温度和荧光强度均最大,分别为380 ℃和228。结论 高分子配合物比小分子配合物具有更好的热性能和发光性能,最佳聚合反应时间为8 h。     

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.     

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.……     

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.     

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.