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171.
采用高能球磨和喷雾干燥法制备了球形磷酸铁锂材料LFP-1,并制作18650实装电池,测试电极片的压实密度,同时选择一种商业化磷酸铁锂材料LFP-2作为对比。测试结果显示,2种LFP材料均由平均粒径为300~500 nm的一次颗粒组成,比表面积为13~15 m2/g,碳质量分数为1.5%左右。通过CR2032纽扣型电池充放电测试表明,在0.2C时,LFP-1的比放电容量约为165 mA·h/g,与商业化磷酸铁锂材料LFP-2相近。制备18650电池的结果表明,商业化磷酸铁锂LFP-2材料制备的电极片的最高压实密度可以达到2.52 g/cm3,显著高于实验室制得的磷酸铁锂材料LFP-1的最高压实密度2.25 g/cm3,这可能与材料的颗粒粒度分布不同有关。 相似文献
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173.
Dérick Rousseau Arthur R. Hill Alejandro G. Marangoni 《Journal of the American Oil Chemists' Society》1996,73(8):983-989
Interesterified and noninteresterified butterfat-canola oil blends, ranging from 100% butterfat to 60∶40 butterfat-canola
oil (w/w) in 10% increments, were evaluated for hardness index (HI), dropping point, viscosity, and viscoelastic properties
at small deformation. Both blending and chemical interesterification diminished HI in a nonlinear fashion. HI changes in interesterified
blends were more pronounced than in noninteresterified blends. Dropping points yielded information on the structure of the
blends. Butterfat’s dropping point (DP) was 34.4°C, whereas that of interesterified butterfat was 37.0°C, which is indicative
of a more structured network for the latter. DP values of blends with 60–90% butterfat (interesterified vs. noninteresterified)
were not significantly different (P<0.05). Interesterified blends had a higher crystallization onset temperature than did noninteresterified blends. All blends
in the liquid state displayed Newtonian behavior. Oscillatory frequency sweep measurements at small amplitude showed that
interesterified blends generally had lower storage moduli (G′) than their noninteresterified counterparts. BothG′ andG″ were frequency-dependent. Replacement of 30% butterfat by canola oil led to notable changes in small deformation measurements,
whereas replacement of 20% butterfat led to big changes in large deformation measurements. 相似文献
174.
A series of liquid polyester polyols from adipic acid (AA), phthalic anhydride (PA), ethylene glycol, propanediol‐1,2, and trihydroxymethylpropane, varying in the molar ratio of PA to AA, were prepared. The effects of the o‐aromatic ring in the molecular chain, which came from PA, on the viscosity, glass‐transition temperature, and thermal degradation temperature of the polyester polyols were studied with viscometry, differential scanning calorimetry, and thermogravimetry. The intrinsic viscosity and glass‐transition temperature increased with the concentration of the o‐aromatic ring increasing. The temperature of the maximum thermal degradation rate for aliphatic polyester polyols was 434.20°C. Two steps of thermal degradation were found when there were o‐aromatic rings in the molecular chain. One thermal degradation temperature was 358.36–360.48°C, and the other was 412.85–427.18°C. Polyester polyols with o‐aromatic rings had higher stability at lower temperatures (<240.00°C). However, aliphatic polyester polyols had higher stability at higher temperatures (300.00–480.00°C). The activation energy and order of degradation were calculated from thermogravimetric curves. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1617–1624, 2002 相似文献
175.
176.
研究试验温度和停放时间对胶料加工性能的影响。结果表明,试验温度对胶料的门尼粘度、门尼焦烧时间和硫化特性均有一定影响。门尼粘度测定的试验温度选择100℃;门尼焦烧时间测定的试验温度一般选120℃,SBR胶料可提高至130℃左右,以缩短试验时间;硫化特性测定的试验温度一般选185℃。试验前模腔达到规定温度后再保持15min,以使转子与模腔温度一致。胶料停放时间应控制在2h左右。 相似文献
177.
The effects of ultrasonic oscillations and die materials on die pressure, productivity of extrusion, melt viscosity of metallocene‐catalyzed linear low density polyethylene (mLLDPE), as well as their mechanism were studied in a special ultrasonic oscillations extrusion system developed in our lab. Die materials used in our experiment included steel, brass, and polytetrafluoroethylene (PTFE). The experimental results showed that ultrasonic oscillations as well as die materials have great influence on the rheological and processing behavior of mLLDPE. Ultrasonic oscillations can greatly increase the productivity of mLLDPE melt extruded through different dies, and can decrease the die pressure and the melt viscosity of mLLDPE. Compared with steel or brass die, mLLDPE melt extruded through PTFE die is more sensitive to ultrasonic oscillations. A possible mechanism for the improved processability of mLLDPE is proposed in this article. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1873–1878, 2003 相似文献
178.
低粘度高固含量醋酸乙烯-丙烯酸酯共聚乳液胶粘剂的研制 总被引:3,自引:4,他引:3
介绍了一种低粘度、高固体含量的醋酸乙烯-丙烯酸丁酯-丙烯酸异辛酯共聚乳液胶粘剂的合成工艺及性能。该乳液粘度低于2500mPa.s,固体含量≥52%,较低的玻璃化温度和良好的耐水性能,应用于卷烟和防水涂料的生产。 相似文献
179.
180.
Good wetting of reinforced fiber by resin was a main factor in the improvement of the interface adhesion of their composites. Ultrasound with a frequency of 20 kHz was used to improve the wettability between aramid fibers and epoxy resin during the winding process of the composites. The effects of ultrasound on the viscosity and surface tension of epoxy resin and on the surface characteristics of aramid fibers were investigated. The wettability of aramid fibers and treated epoxy resin under different conditions and of aramid fibers and epoxy resin under ultrasonic online treatment were compared. The results indicated that the main action of ultrasound was to force epoxy resin to impregnate aramid fibers, in addition to the influence of ultrasound on the properties of epoxy resin and aramid fibers. The results of microdebond testing showed that the interfacial shear strength (IFSS) of aramid/epoxy composites could be 26% higher than that of untreated composites because of the improved wettability between aramid fibers and epoxy resin subjected to ultrasonic online treatment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献