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首页> 外文期刊>The Journal of Supercritical Fluids >Production of controlled polymeric foams by supercritical CO2
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Production of controlled polymeric foams by supercritical CO2

机译：通过超临界二氧化碳生产受控聚合物泡沫

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The foaming of polystyrene and cellulose acetate has been studied using a technique based on the saturation of the polymer by supercriticat CO2 and the rapid decompression of samples. The diameter of resulting microcellular structures has been controlled manipulating the process conditions. The experiments performed at various foaming temperatures (from 55 to 125 degrees C for polystyrene and from 215 to 245 degrees C for cellulose acetate) and at 230 bar for polystyrene and at 250 bar for cellulose acetate, showed that higher temperatures produce larger cells (with mean diameters from 5 to 65 mu m for polystyrene and from 7 to 70 mu m for cellulose acetate). The effect of foaming pressure has been also tested, at T = 75 degrees C for polystyrene and at T = 230 degrees C for cellulose acetate, from 80 to 230 bar for polystyrene and from 100 to 250 bar for cellulose acetate. Larger pressures generate smaller cells with mean diameters from 60 to 15 mu m for polystyrene and from 80 to 20 mu m for cellulose acetate. The influence of the contact time has also been studied: from 60 to 240 min for polystyrene and from 180 to 480 min for cellulose acetate; larger contact times assure homogeneous CO2 diffusion inside the sample and, consequently, a symmetric microcellular structure. (C) 2006 Elsevier B.V. All rights reserved.
机译：聚苯乙烯和醋酸纤维素的发泡已使用基于超临界二氧化碳使聚合物饱和和样品快速减压的技术进行了研究。所产生的微孔结构的直径已通过控制工艺条件得到控制。在各种发泡温度下（聚苯乙烯从55到125摄氏度，醋酸纤维素从215到245摄氏度），聚苯乙烯在230巴和醋酸纤维素在250巴下进行的实验表明，较高的温度会产生较大的泡孔（聚苯乙烯的平均直径为5至65微米，醋酸纤维素的平均直径为7至70微米。还已经测试了发泡压力的影响，对于聚苯乙烯，在T = 75摄氏度，对于乙酸纤维素，在T = 230摄氏度，对于聚苯乙烯，为80至230巴;对于乙酸纤维素，为100至250巴。较大的压力会产生较小的孔，聚苯乙烯的平均直径为60至15微米，而醋酸纤维素的平均直径为80至20微米。还研究了接触时间的影响：聚苯乙烯为60至240分钟，乙酸纤维素为180至480分钟。较大的接触时间可确保样品内部CO2均匀扩散，因此可确保对称的微孔结构。 （C）2006 Elsevier B.V.保留所有权利。

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