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大湖公司为应对HCFC-141b发泡剂的禁用,推出了用于聚氨酯和聚异氰脲酸酯硬泡的反应型阻燃剂Firemaster 520。 由HCFC-141b发泡剂转向使用戊烷发泡剂,大大增加了聚氨酯和聚异氰脲酸酯硬泡用阻燃剂的需求。使用HCFC- 相似文献
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在相同的基础配方和异氰酸酯指数(300)下,对发泡剂HCFC-141b、HFC-245fa在聚氨酯PIR连续板材中的应用性能进行了研究,对比了HCFC-141b和HFC-245fa在发泡性能(反应过程中的泡沫爬升曲线、反应速率曲线、压力曲线等)、阻燃性能、力学性能和保温性能上的差异。结果表明,发泡剂由HCFC-141b切换到HFC-245fa后,聚氨酯泡沫压缩强度各向异性减弱,尺寸稳定性更好;泡沫的阻燃性能基本未变,氧指数由28.0%增加到28.2%,烟密度和火焰高度也都稍有增加;泡沫导热系数由20.65 mW/(m·K)升高到21.27 mW/(m·K)。 相似文献
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郭智臣 《化学推进剂与高分子材料》2009,(5)
日本东洋橡胶工业公司为适应环保的需要,防止对大气臭氧层的破坏,不用氟类发泡剂HCFC-141b,改用水作发泡剂,研制出高阻燃型水发泡硬质聚氨酯泡沫 相似文献
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郭智臣 《化学推进剂与高分子材料》2009,7(5):43-43
日本东洋橡胶工业公司为适应环保的需要,防止对大气臭氧层的破坏,不用氟类发泡剂HCFC-141b,改用水作发泡剂,研制出高阻燃型水发泡硬质聚氨酯泡沫塑料。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969. 相似文献
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利用组件技术开发化工原理实验课件,给出了系统层、组件库层和应用层的架构划分。重点讨论了组件库的设计,给出了流体阻力这一典型实验的实现描述。实践证实,基于组件技术可以提高仿真实验的开发效率。 相似文献