共查询到20条相似文献,搜索用时 31 毫秒
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以水稻秸秆液化物为聚醚多元醇,与多苯基多亚甲基异氰酸酯反应,制备聚氨酯硬质泡沫(PURF)。采用热重分析、残炭层表面分析、极限氧指数测定、傅里叶变换红外光谱与热重分析联用,探索了一系列磷系阻燃剂、三聚氰胺阻燃PURF的燃烧性能。结果表明:三聚氰胺可在残炭层中起到隔离作用;三聚氰胺与磷阻燃剂配合使用时,较单独使用的残炭层更完整,且可降低气体中可燃物的浓度,获得更好的阻燃效果。 相似文献
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研究了咪唑基离子液体1-丁基-3-甲基咪唑六氟磷酸盐([BMIM]PF6)对三聚氰胺(C3H6N6)进行改性后对硬质聚氨酯泡沫阻燃性能的影响。结果表明,改性后的C3H6N6阻燃效果明显增加,氧指数从22.3提高到24.95。在改性过程中,[BMIM]PF6的添加量对阻燃效果有明显的影响,当[BMIM]PF6与C3H6N6的质量比为4∶6时,阻燃效果最好。与改性前相比,改性后的C3H6N6可以有效的提高材料的阻燃性,水平燃烧速度从67.6 mm/min降低到33.4 mm/min。通过热分析可以看出,改性后C3H6N6阻燃硬质聚氨酯泡沫热分解温度升高,分解残留物增加,放热量大大减小,离子液体的加入可有效抑制硬质聚氨酯的分解,提高热稳定性。 相似文献
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《玻璃钢/复合材料》2014,(5)
正4月30日,巴斯夫宣布庞巴迪为蒙特利尔地铁制造的468辆新一代地铁客车将采用巴数特三聚氰胺树脂泡沫作为顶棚吸音隔热材料。庞巴迪此次选用的巴数特部件由泡沫生产商Artik/OEM公司提供。巴数特泡沫的密度仅为9公斤/立方米,有助于减轻整体车重,从而帮助庞巴迪实现提高客车性能和能源效率的目 相似文献
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H. Brown 《Journal of the American Oil Chemists' Society》1979,56(11):729A-729A
A recent space exploration has revealed that in the far reaches of outer space matter attains a state of complete weightlessness.
Herman Brown, reporting on his latest spaced-out venture, indicates that weightless fatty acids obtained from the Superba
Galaxy are ideally suited for the manufacture of improved food additives. What a magnificent way to provide the diet-control
foodstuffs of the 21st Century! 相似文献
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比较了添加自制有机硅匀泡剂与国内外主流匀泡剂的聚醚组合料的乳化性能和流动性能,及其聚氨酯硬泡的吸水率和尺寸稳定性。结果表明,对于环戊烷发泡体系,添加自制有机硅匀泡剂XHG-295和国内外主流匀泡剂的聚醚组合料的乳化性能和流动性能及其聚氨酯硬泡的吸水率和尺寸稳定性都接近;对于HCFC-141b发泡体系,添加自制有机硅匀泡剂XHG-299和国内外主流匀泡剂的聚醚组合料的乳化性能和流动性能及其聚氨酯硬泡的吸水率和尺寸稳定性都接近。XHG-295和XHG-299能达到家电组合料和保温板材组合料生产对匀泡剂的质量要求。 相似文献
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The fragmentation of a small object from outer space in the form of a rectangular parallelepiped in a planetary atmosphere is examined. The model for the interaction of an object with an atmosphere and its fragmentation developed by the authors is used in calculations of the Sikhote-Alin’ meteoroid as an example. The results are close to analogous calculations for a spheroidal meteoroid and agree satisfactorily with actual data. This suggests that the shape of a small object from outer space has little effect on its fragmentation in a planetary atmosphere. 相似文献
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泡沫是气体分散于液体中的多相分散体系。气体是分散相,液体是分散介质。制备泡沫的过程中,液体中的气泡在密度差的作用下易在液面上形成以少量液体构成的液膜隔开气体的气泡聚集物——泡沫。泡沫流体是气体组成的气泡分散体系,具有极高的表面自由能,是热力学不稳定体系,所以泡沫会发生衰变,原因普遍认为有两方面:泡沫中液体的析出和气体穿透液膜扩散。泡沫以其独特的性能在钻井、采油、采气、消防等领域中得到越来越多的应用,如泡沫驱油、泡沫钻井、泡沫水泥固井、泡沫酸酸化、泡沫冲沙洗井、泡沫压裂、泡沫采气、蒸汽驱泡沫调剖、泡沫-聚合物复合驱等, 相似文献
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One of the unit operations in foam technology is foam generation in a liquid/gas mixer. The foaming process of an aqueous liquid system with a surface-active agent in a rotor-stator mixer has been studied, and it was found that it could be represented by a mixing characteristic relating the liquid flow rate to the maximum gas flow rate needed to produce a foam without ‘blow-by’. Too high a gas flow rate resulted in a short-circuiting flow of gas via the rotor shaft to the outlet. The influence of the number of rotor-stator blades, equipment size and operating pressure on the behaviour of the foam mixer has been investigated. 相似文献
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A self-oscillation model of the operation of an aerodynamic jet foam breaker is proposed, which takes into account the generation of secondary fine foam. 相似文献
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