Polycaprolactone/Clay Nanocomposites Prepared in Supercritical Carbon Dioxide

• Main Authors: Jhen-Gang Lai, 賴振剛
• Other Authors: Yeong-Tarng Shieh
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/30379168725818344975

碩士 === 國立雲林科技大學 === 化學工程與材料工程研究所 === 95 === An environmentally friendly intercalation method to prepare polycaprolactone (PCL)/clay nanocomposites in supercritical carbon dioxide (sc CO2) is presented. In this method, sc CO2 assists melting of PCL and mediates the intercalation of PCL. The intercalation of the physically mixed PCL/clay blends is studied as a function of pressure and temperature of sc CO2 treatments using wide angle X-ray diffractometer (WAXD), differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA), and dynamic mechanical analysis (DMA). The unmodified (NaMMT) and organic-modified (OMMT) montmorillonite clays are comparatively studied. WAXD patterns find that PCL is slightly intercalated in NaMMT but significantly intercalated in OMMT. The interlayer spacing is considerably up as much as 1.59 nm from 1.94 nm for OMMT to 3.53 nm for the OMMT/PCL 10/90 sample. At a given temperature, the interlayer spacing of the intercalated OMMT monotonically increases with CO2 pressure but, at a given pressure, exhibits a maximum at near 46 oC. A larger molecular weight of PCL is found to give a smaller interlayer spacing of the intercalated OMMT. DSC data find that the PCL-intercalated OMMT expedites the melt-crystallization rate of PCL from the melt but it suppresses the crystallinity of PCL. TGA data find that more PCL can be intercalated into OMMT in the PCL-rich blends. DMA data find that the PCL-intercalated OMMT is an effective reinforcement for PCL.