含磷阻燃剂对硬质聚氨酯泡沫塑料阻燃性能和力学性能的影响

比较了4种不同液体含磷阻燃剂——甲基膦酸二甲酯(DMMP)、磷酸三(β-氯异丙基)酯(TCPP)、二甲基膦酸丙酯(DMPP)以及1种新型阻燃剂膦酸二甲酯1201(DM-1201)对硬质聚氨酯泡沫塑料(RPUF)的阻燃效果和抑烟效果的影响。同时考察了这4种阻燃剂对RPUF一些物理性能的影响,包括吸水率、导热系数、压缩强度。研究表明,DM-1201的阻燃、抑烟效果最好,添加DM-1201的试样其氧指数(LOI)从纯RPUF的19.5%提高到了25.7%,单位质量的烟密度等级(SDRpm)也较纯RPUF降低了12.3%;在改善材料的压缩强度方面也最有效,垂直于泡孔生长方向上的压缩强度较纯的RPUF提高64.1%;而且添加DM-1201对RPUF的导热系数影响最小。热失重分析表明,DM-1201在提高RPUF的残炭量方面也比另外3种阻燃剂好。     

三聚氰胺苯基磷酸盐的合成及在硬质聚氨酯泡沫中的应用

以三聚氰胺(MEL)和苯基磷酸(PPA)为原料,合成出一种磷氮类阻燃剂——三聚氰胺苯基磷酸盐(MPP),采用核磁共振磷谱和红外光谱对其结构进行了表征。通过极限氧指数(LOI)、UL 94和锥形量热测试对MPP阻燃的硬质聚氨酯泡沫(RPUF)的燃烧性能进行了研究。结果表明,当MPP添加量为15%(质量分数)时,阻燃RPUF的LOI为27%,达到了UL 94V-0级,其热释放速率峰值(PHRR)相对于未阻燃RPUF降低了约44%。采用热重分析(TGA)研究了阻燃RPUF的热分解特性,结果表明,添加15%MPP的阻燃RPUF的压缩强度和弯曲强度分别比未阻燃RPUF提高了50%和27%。导热系数测试结果表明,添加15%MPP的阻燃RPUF的导热系数稍微有所增加,约为0.025 9 W/(m·K)。     

碳酸镍对PP/MPP/PEPA膨胀阻燃体系的协同作用

以碳酸镍(NC)为阻燃协效剂,采用多聚磷酸蜜胺(MPP)和笼状季戊四醇磷酸酯(PEPA)复配阻燃剂,制备了具有良好阻燃性能的无卤阻燃聚丙烯(PP/IFR)。研究了NC用量对PP阻燃性能的影响,并分析了其阻燃协同作用机理。结果表明,添加少量的NC即可显著提高PP的阻燃性能;当NC添加量为3%时,阻燃PP的氧指数高达37.5%。TGA、FT-IR分析和体式显微镜、SEM观测结果表明,添加NC可以催化MPP/PEPA间的酯化反应,形成更多的交联网络结构,促进PP/IFR体系成炭,形成更致密的炭层,从而提高材料的阻燃性能。     

以水解淀粉为碳源的膨胀阻燃剂的制备及应用

将马铃薯淀粉酸水解,非水条件下与三氯氧磷交联,制得氯化淀粉磷酸酯(SPC),后者分别与二乙醇胺、三聚氰酰胺反应合成2种环保型膨胀阻燃剂二羟乙基淀粉磷酰胺(SPE)与淀粉磷酸酯密胺(SPM)。测定二者含磷量,最高分别可达0.157%(wt,质量分数,下同)、0.169%。以XRD、IR表征了原料和样品结构。将2种阻燃剂分别与聚氨酯原料混合,采用全水发泡工艺制备系列阻燃聚氨酯(IFR-PU),以极限氧指数(LOI)及垂直燃烧实验对阻燃样品进行阻燃性能测试。结果表明,随着SPE、SPM添加量的增加,聚氨酯的LOI值逐渐增大,当SPE的添加量为30%时,LOI值为22.4%,未达阻燃级别。而SPM的添加量为30%时,LOI值可达29%,达到阻燃UL-94-V0级别,SPM的阻燃效果较SPE更好。     

磷改性膨胀石墨对硬质聚氨酯泡沫燃烧性能的影响

用六氯环三磷腈(HCCP)对可膨胀石墨(EG)进行改性,所得改性可膨胀石墨(EGP)用于硬质聚氨酯泡沫(RPUF)的阻燃处理。利用红外光谱、热重分析和扫描电镜表征EGP的结构特征。利用万能试验机、极限氧指数(LOI)和锥形量热(CONE)研究了EGP对RPUF力学性能和阻燃性能的影响,通过扫描电镜和热重分析研究了RPUF样品燃烧后残炭的微观形貌和阻燃机理。分析结果表明,随着EG或EGP添加量的增加其LOI随之增加,在相同添加量的情况下RPUF/EGP的LOI最高,且其力学性能优于RPUF/EG的力学性能;由于EGP促使RPUF分解产生更加致密坚固的炭层,所以RPUF/EGP的点燃时间比RPUF/EG推迟了4s,其热释放速率峰值、总的热释放量、烟释放速率峰值和总的烟释放量分别比RPUF/EG降低了9.1%、5.9%、19.0%和33.8%,EGP表现出优于EG的阻燃抑烟性能。     

一种新型膨胀型阻燃剂合成及阻燃性能研究

采用新戊二醇、三氯氧磷为原料,在超声场中合成了新戊二醇磷酰氯,采用超声波技术提高产品的产率。再将新戊二醇磷酰氯与苯并三氮唑反应生成一种新型膨胀型阻燃剂3-(5,5-二甲基-1,3-二氧杂-2-磷杂环己基磷酰基)苯并三氮唑,通过对制得的产品结构进行了表征,测定了该阻燃剂的膨胀度,膨胀度ID为49.8cm~3/g。将阻燃剂应用于制备阻燃性聚丙烯,通过氧指数法考察了阻燃性聚丙烯的阻燃性能,氧指数(LOI)值为27.1。     

哌嗪改性木质素/磷酸铝双重包覆红磷的制备与阻燃性能

以哌嗪改性木质素(LP)和磷酸铝为囊材,制备了具有多层次阻燃性能的无卤微胶囊化红磷阻燃剂,并用于改善丙烯腈-丁二烯-苯乙烯(ABS)树脂的阻燃性能。利用透射电子显微镜、扫描电子显微镜、红外光谱和热重分析等测试手段对阻燃剂的形貌和结构进行了表征,研究了阻燃剂添加量对ABS阻燃性能的影响。结果表明,红磷被LP和磷酸铝严密包覆;添加25%阻燃剂的ABS复合材料燃烧后可形成致密、厚实的残炭层,阻燃级可达到UL94 V-0等级,极限氧指数达到26.1%。与未添加阻燃剂ABS树脂相比,热释放速率峰值降低了63.1%,总烟雾释放量降低了25.8%。     

4A分子筛对PP/MPP/PEPA膨胀阻燃体系的协同作用

以4A分子筛为阻燃协效剂,采用多聚磷酸蜜胺(MPP)和笼状季戊四醇磷酸酯(PEPA)复配阻燃剂,制备了具有良好阻燃性能的无卤阻燃PP。研究了4A分子筛用量对PP阻燃性能和协同作用的影响。结果表明:添加少量的4A分子筛即可显著提高PP的阻燃性能;当MPP/PEPA/4A分子筛添加量分别为12%、8%和2%时,阻燃PP的氧指数高达33。TGA、FTIR分析和体视显微镜及SEM观测结果表明:添加少量的4A分子筛可以催化MPP/PEPA间的酯化反应,促进体系成炭,形成更致密的炭层,从而提高材料的阻燃性能。     

TiO_2对PP/MPP/PEPA膨胀阻燃体系的协同作用

以TiO2为阻燃协效剂,采用多聚磷酸蜜胺(MPP)和笼状季戊四醇磷酸酯(PEPA)复配阻燃剂,制备了具有良好阻燃性能的无卤阻燃聚丙烯(PP)。研究了TiO2用量对PP阻燃性能和协效作用的影响。结果表明:添加少量的TiO2即可显著提高PP的阻燃性能;当MPP/PEPA/TiO2添加量分别为12%、8%和1%时,阻燃PP的氧指数高达31.5。TGA和FTIR分析及SEM和体式显微镜观测结果表明:添加TiO2可以催化MPP/PEPA间的酯化反应,促进体系成炭,形成更致密的炭层,从而提高材料的阻燃性能。     

一种新型含氯的磷-膦酸酯阻燃聚氨酯的阻燃性能

采用自制新型含磷-氯阻燃剂O，O’-二（2-氯乙基），O”-[2-（2-双氟乙氧基）磷酰基]丙基磷酸酯（DCEPP），制备了阻燃聚氨酯泡沫（PUF）。探讨了阻燃剂添加量对阻燃材料的阻燃性能和力学性能的影响以及阻燃PUT的热老化性能，实验证明，添加（w）15％的DCEPP能使PUF氧指数达到25％，水平燃烧实验表明，添加（w）10％的DCEPP，燃烧时间和长度为0，无熔滴现象，并能通过CAL 117D法实验．热老化实验证明，阻燃剂DCEPP基本不影响阻燃PUF的阻燃性能和伸长率及柱伸强度。     

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.