| Summary: | 碩士 === 中國文化大學 === 化學工程與材料工程學系奈米材料碩士班 === 101 === This study is goal at studying the foaming behavior of PCL-PS (polycaprolactone-co-styrene) with supercritical carbon dioxide (scCO2). We study the structure of foam cells and their physical properties in different operation conditions.
At the outset of this study, we using a vacuum kneader to mix different proportions of the PCL-PS blend, from five different weight ratio (85:15, 75:25, 65:35, 50:50, 25:75), by changing the foaming temperature from 40 to 50 , the foaming pressure from 30MPa to 40MPa, the saturation time from 1h to 3h and pressure relief time from 2s to 15s, and then observed of the foaming results of the prepared PCL-PS blend. Then A scanning electron microscope (SEM) is used to study the cell morphology and a thermal differential scanning calorimetry (DSC) is used to measure physical properties . Finally, the results of a melting point , is calculated by computer software to seek the pore diameter and enthalpy , and re-use the formula to calculate the cell average size , the cell density and degree of crystallinity .
In the cell morphology, the experimental results showed that when the foaming temperature increases, the cell average size larger but the cell density becomes smaller, when the foaming pressure and increase, the cell average size becomes smaller but the cell density becomes large. Finally, the study found that the saturation time and pressure relief time in the minimum impact on cell morphology.
In physical properties, the experimental results, when the foaming temperature and the foaming pressure is different, the melting point and the crystallinity will increase with the foaming temperature or foaming pressure increase, and it up or down.
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