Preparation of The mCOC Foaming Material by Supercritical Carbon Dioxide
| Autor: | Kun Lin Li, 李坤霖 |
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| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 This experiment is using supercritical carbon dioxide is to prepare mCOC foaming materials and look for the best foaming temperature and pressure. Also, the experiment studying the effect on the mCOC foamed body which caused by the operation conditions such as temperature, pressure, and soaking time. Furthermore, the changes in degree of crystallization before and after foamed, Tg, dielectric constant, and the intensity of shock-resistant are being probed. Learned by the experimental result, regarding supercritical carbon dioxide as the blowing agent, the temperature of making mCOC foamed must be controlled above 95 ℃, the higher the temperature is, the more obvious the foam is. Under the better foaming temperature of 110 ℃,130℃, when using higher operation pressure, foam density and cell density of material will be more heavy, and its hole degree, volume expansion rate and cell sizes will be smaller. Under the same temperature and pressure, when the soaking time increases, the foam density of material and the cell size will become smaller, and its will hole degree, volume expansion rate and cell density will be larger. At present, the minimum cell size of foam material is 23.88 μm, and the biggest cell density is around 1011 cell/cm3. Under the control temperature of 130℃, pressure of 13.79MPa, and the soaking time of 300 minutes, we can obtain the low electricity foamed materials with dielectric constant around 1.2. However, its shock-resistant intensity will decrease as well. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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