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Mijeong Han David E. Nikles 《Journal of polymer science. Part A, Polymer chemistry》2000,38(18):3284-3292
A series of amine–quinone diol monomers, containing the 2,5‐diamino‐1,4‐benzoquinone group, were synthesized where the alkyl group on the amine was varied from methyl to ethyl to n‐propyl. Polyurethanes were prepared from these monomers by condensation polymerization in N,N‐dimethylformamide solution with toluene diiscyanate and poly(tetrahydrofuran) diol (Mn = 650). These amine–quinone polyurethanes were used as binders in metal particle tape. Samples were exposed to pH 2.0 aqueous buffer and the all amine–quinone polymers were shown to be superior in their ability to protect the iron particle against corrosion, relative to the commercial binders. There was no significant difference in the ability of the three amine–quinone polymers to inhibit corrosion. Clearly the increasing the steric bulk at the nitrogen did not affect their ability to inihibit corrosion. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3284–3292, 2000 相似文献
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David E. Nikles Antony P. Chacko Jeng-Li Liang Russell I. Webb 《Journal of polymer science. Part A, Polymer chemistry》1999,37(14):2339-2345
The amine-quinone diol monomer 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone (AQM-1) was prepared by the condensation of 2-(N-methylamino)ethanol with hydroquinone in the presence of oxygen and copper(II) chloride. This crystalline monomer was used to prepare a series of amine-quinone polyurethanes by condensation polymerization, either in the melt or in DMF solution, with toluene diisocyante and an oligomeric diol either poly(1,2-butylene glycol) or polytetrahydrofuran. The amine-quinone functional group was incorporated into the polymer mainchain, giving red-brown polyurethanes that had molecular weights in the range of 20,000–80,000 and were soluble in THF, MEK, DMF, and DMSO. The thermal properties were consistent with a two-phase morphology with an amorphous soft segment, containing the oligomeric diol, and a microcrystalline hard segment, containing AQM-1. These polymers had a high affinity for the surface of commercial iron particles used in state of the art magnetic tape and prevented the corrosion of the particles. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2339–2345, 1999 相似文献
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非均匀加热条件下内插扭带管强化传热模拟分析 总被引:2,自引:0,他引:2
以水为工作介质,采用欧拉多相流模型和非平衡沸腾模型,当流速在0.3~0.7m·s-1范围内、工作压力为4.5MPa、热流密度为2MW·m-2时,数值模拟了内插扭带管和光管管内流动过冷沸腾传热.对比了两种管道的换热系数、气泡份额、流动速度、流场流线、固体组件温度和压降,分析了内插扭带管的综合性能.结果表明,与光管相比较,... 相似文献
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本论文采用水系流延技术制备了95氧化铝陶瓷基片,主要对浆料中各种添加剂的作用作了系统研究.分散剂通过与无机粉料的吸附,提供双重稳定效应使浆料具有较好的分散性,实验中分散剂PAA(聚丙烯酸)最佳的用量为0.5wt;.粘结剂PVA(聚乙烯醇)最佳用量为4.5wt;.塑化剂PEG(聚乙二醇)的加入可以降低粘结剂的玻化温度,提高坯片柔韧性.塑化剂与粘结剂的用量比值(R)在1~1.2之间为宜.最终获得了具有一定强度、韧性、表面光滑的坯片,烧结出密度为3.785g/cm395氧化铝陶瓷基片. 相似文献
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In this work, we report a facile and effective strategy to generate patterned wrinkles. This strategy includes first adhering a thin poly(dimethylsiloxane) (PDMS) film (<82 µm) on porous conductive adhesive tape (CAT), followed by sputter coating of Au onto PDMS under vacuum condition, which results in formation of patterned wrinkles on the Au‐PDMS bilayer. CAT was found to induce local stretching of PDMS thin film, which was the key for controlled wrinkle formation. Compared with previous wrinkling methods, our strategy is simpler and gives smaller feature sizes (down to 300 nm).
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基于带状弹簧的空间望远镜精密展开技术进展 总被引:1,自引:0,他引:1
采用带状弹簧构造的可折叠多杆并联结构对卡塞格林型望远镜的次镜进行支撑,并结合在轨调节,可以实现口径<1 m的可展开空间望远镜。描述了基于带状弹簧的可展开空间望远镜的结构特点,介绍了近年来发表的四杆支撑、八杆支撑、三杆支撑和六杆支撑等4种基于带状弹簧的空间望远镜精密展开技术的研究进展。建议针对带状弹簧空间望远镜的精密展开技术,应进一步开展结构动力学建模、结构优化以及误差的光电测量和校正等方面的研究。此外,在模拟微重力环境下展开实验也有助于推动展开动力学和展开精度的研究,而非对称展开结构将是今后该项技术的研究方向之一。认为开展基于带状弹簧的空间望远镜精密展开技术的研究将促进基于微小卫星平台的高分辨率遥感成像和自由空间光通信技术的发展。 相似文献