CMSs/PET微胶囊阻燃PET纤维制备与表征

将采用原位聚合法自制的核-壳型碳微球(CMSs)/聚对苯二甲酸乙二醇酯(PET)微胶囊(PCMSs)作为阻燃剂,采用熔融纺丝法制备阻燃PCMSs/PET功能纤维。通过扫描电镜、声速仪、强伸仪、极限氧指数仪等测试设备对添加不同质量分数的阻燃剂的阻燃功能纤维的结构及性能进行测试和表征。结果表明:当阻燃剂PCMSs的质量分数为0.6%时,PCMSs在PET纤维基体中的分散性和相容性良好,此时纤维表面较为光滑,同时具有优良的吸湿性能和阻燃性能,但其力学性能稍低于PCMSs质量分数为0.2%时的PCMSs/PET纤维。     

不同纳米碳材料阻燃聚对苯二甲酸乙二醇酯复合材料性能的表征

以碳微球(CMSs)、碳纳米管(MWNTs)、碳微球(CMSs)与碳纳米管(MWNTs)复配的3种材料,通过熔融共混法分别对聚对苯二甲酸乙二醇酯(PET)进行阻燃改性,制备出不同纳米碳材料阻燃PET复合材料。采用极限氧指数(LOI)法、垂直燃烧法、热重分析、扫描电镜等方法,测试和表征了CMSs/PET、MWNTs/PET、CMSs/MWNTs/PET复合材料的阻燃性能、热稳定性能、分散性及力学性能。结果表明,质量分数为1%的CMSs可使PET的LOI明显提高到28.9%,但对其抗熔滴性能的改善并不明显;同质量分数的MWNTs的添加,可有效提高PET的抗熔滴性能,其熔滴数由原PET的24d/min减少为6d/min;且CMSs与MWNTs具有协同阻燃效应,当两者的质量比为1∶2时,CMSs/MWNTs/PET的LOI为27.3%,且其熔滴数仅为4d/min;三者的垂直燃烧级别都由原PET的V-2级上升为V-0级,热稳定性都有所提高,但力学性能都有一定程度的下降。     

聚苯胺包覆碳微球/聚对苯二甲酸乙二醇酯复合阻燃材料的制备及性能

通过化学氧化法合成聚苯胺,并利用原位聚合法将聚苯胺(PAN)包覆在碳微球(CMSs)上,采用熔融共混法制得阻燃聚苯胺包覆碳微球/聚对苯二甲酸乙二醇酯复合材料(CMSs-PAN/PET)。采用扫描电镜、红外光谱仪、热重和氧指数仪等,对其形貌结构、分散性、热稳定性能、阻燃性能和力学性能进行了分析和研究。结果表明,聚苯胺包覆后的CMSsPAN与原始CMSs相比,在PET基体中的分散性得到提高,CMSs-PAN/PET的拉伸强度比CMSs/PET提高了28.1%;与纯PET相比,CMSs-PAN/PET复合材料的热稳定性明显提高,其极限氧指数达到32.1,提高了10.4。     

CMSs/APP对PET阻燃性能的影响

结合阻燃剂复配技术,以碳微球(CMSs)与聚磷酸铵(APP)为添加材料,通过熔融共混法制备了CMSs/APP/PET复合材料。采用锥形量热仪(CONE)、极限氧指数(LOI)、垂直燃烧测试(UL-94)、扫描电镜(SEM)等对CMSs/APP/PET复合材料的阻燃性能进行了研究,并对CMSs与APP的配比及含量进行优化。结果表明,单独添加3%CMSs可使PET的LOI值提高到25.1%,释热速率峰值(PHRR)从513.22 kW/m²下降到382.51 kW/m²,但该复合材料不能通过UL-94的测试;单独添加3%APP仅可使PET的LOI值提高到21.9%,但其UL-94可达到V-0级。通过探讨不同配比的CMSs/APP对PET阻燃性能的研究发现,在CMSs/APP的添加量为2%,质量比为1∶2时,CMSs/APP/PET复合材料的阻燃效应最佳,其LOI值可达27.5%, PHRR值下降了45.4%,总产烟量(TSP)由14.4 m²下降到12.4 m²,残炭量由13.2%增加到17.3%,且UL-94可达到V-0级,可满足PET在不同燃烧方向的阻燃要求。     

单体浓度对PANI-CMSs/PET阻燃复合材料性能的影响

采用不同单体浓度的聚苯胺包覆碳微球与PET共混后制得PANI-CMSs/PET阻燃复合材料,研究了单体浓度对阻燃复合材料性能的影响,同时分析了复合材料的力学性能、阻燃性能及导电性能。结果表明:当单体浓度为1.5mol/L时,阻燃复合材料的拉伸强度达到39.78MPa,冲击强度为3.48kJ/m2,此时电阻率最低,导电性能最好,极限氧指数达到32.02%,PET的阻燃性能提高47.6%。     

低密度碳空心微球的制备及酚醛树脂空心微球复合材料的性能

以BJO-0930酚醛树脂空心微球为原料,通过酸洗、预氧化、碳化三步工艺,成功制备球形度好、强度高的碳空心微球,并与热固性酚醛树脂复合,热压成型得到轻质酚醛树脂/空心微球复合材料。系统考察了碳化温度、循环酸洗、预氧化等对碳空心微球强度的影响。复合材料的力学性能和隔热性能分别通过压缩性能以及热导率测试进行表征。结果表明:直接碳化得到的碳空心微球破球率高、强度低;通过循环酸洗可以有效去除树脂球的灰分,破球率由28.07%降低至18.03%;进一步预氧化处理可以显著提高碳空心微球的强度,其破球率和等静压破球率分别为10.03%和17.34%;制备得到的酚醛树脂/碳空心微球复合材料具有优异的隔热性能和力学性能,热导率降低至0.115 W·m~(-1)·K~(-1),压缩强度为46.02MPa。     

液相沉积法制备氢氧化镁包覆碳微球复合阻燃材料

以碳微球(CMSs)、氢氧化钠和氯化镁为原料,采用液相沉积法制备了Mg(OH)_2/CMSs复合阻燃材料,通过场发射扫描电镜(SEM)和X射线衍射仪(XRD)分析了材料的微观形貌和结构;并结合Mg(OH)_2/CMSs复合阻燃材料与聚对苯二甲酸乙二醇酯(PET)共混制备Mg(OH)_2/CMSs/PET复合材料,通过数显氧指数测试仪分析其阻燃性能。结果表明,通过液相沉积法Mg(OH)_2包覆在CMSs表面,且包覆效果较好;Mg(OH)_2/CMSs复合阻燃材料燃烧时分解生成的氧化镁(MgO)、水和残余炭层,使得Mg(OH)_2/CMSs/PET复合材料的极限氧指数由PET的21.0%增加到27.5%,并具有优良的抑烟性和抗熔滴性,提高了PET材料的阻燃性能。     

羊毛纤维微波辐照下接枝碳微球的接枝率影响因素的研究

采用微波辐照方法将碳微球(CMSs)接枝在羊毛纤维表面。研究了CMSs悬浮液的制备工艺对羊毛纤维接枝率和阻燃性能的影响。通过炭化残渣量转换极限氧指数(LOI)的方法测试阻燃羊毛纤维的阻燃性能。结果表明:CMSs的接枝率达到6%时制得的阻燃羊毛纤维的LOI值可以达到29.5%,使羊毛的阻燃性能提高了17%,洗涤30次后LOI值仍达到29.2%。     

CMSs-An/PET复合阻燃材料的制备和性能

先用酸氧化法修饰碳微球(CMSs)的表面,再用化学合成法将苯胺(An)接枝在CMSs上制备CMSs-An复合物,最后用熔融共混法制备了CMSs-An/PET复合材料。采用扫描电镜(SEM)、红外光谱仪(FTIR)、热重(TG)、氧指数仪和垂直燃烧仪等手段对其形貌结构、分散性、热稳定性能、阻燃性能和力学性能进行了表征。结果表明,与原始CMSs相比,苯胺修饰后的CMSs-An在PET基体中的分散性提高了,使CMSs-An/PET的抗拉强度比CMSs/PET提高了20.8%;与纯PET相比,CMSsAn/PET复合材料的热稳定性明显提高,其极限氧指数提高了7.5达到29.2,垂直燃烧级别由V-2级上升到V-0级。     

CuO对锂硫电池的性能影响

采用液相浸渍法制备了氧化铜(CuO)包覆的碳/硫(C/S)复合材料,对包覆材料的性能进行了分析。通过包覆可降低C/S复合材料与电解液的直接接触,减少电解液对正极材料的侵蚀,提高C/S复合材料的循环性能。包覆CuO后的锂硫电池充放电循环20次,容量保持率从75%提高到93.04%。     

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 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.     

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.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.