Solid State Polymerization of Polycaprolactone and Phase Behavior of Polycaprolactone/Poly(vinyl chloride) Blends in Supercritical CO2 Fluids

• Main Authors: Huang-Shung Yang, 楊晃祥
• Other Authors: Yeong-Tarng Shieh
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/46446385844622073146

碩士 === 國立雲林科技大學 === 工業化學與災害防治研究所碩士班 === 90 === This report includes two parts. The first part presents results on the investigated of solid-state polymerization and phase behavior of polycaprolactone (PCL) in supercritical carbon dioxide fluids (SCF CO2). PCL is found to be miscible with SCF CO2, the miscibility depending on CO2 conditions, via interactions between the carbonyl groups of PCL and CO2. In addition to solid state polymerizations, which could increase molecular weights of PCL, transesterification reactions of PCL are found as well, decreasing molecular weights of PCL. The extent of solid state polymerizations and transesterification reactions are dependent upon CO2 conditions, with the 36-atm CO2 giving a dominant solid state polymerization while 84-atm and 304-atm CO2 giving both reactions. PCL dissolved in SCF CO2 can perform a recrystallization during depressurizing of CO2 and exhibits a disordered structure of lamellar stacks as evidenced by zero-angle scattering from SAXS measurements. The second part presents results on the effects of SCF CO2 on the phase behavior of PCL/PVC blends. Prior to SCF CO2 treatments, DSC and DMA data demonstrate that PCL/PVC blends in this study are compatible blends. SAXS data demonstrate that thickness of both crystalline layer and amorphous layer in the lamellar stacks increase with increasing PVC contents in the blends. The phase segregation distance of PVC increases with increasing PVC contents in the PCL/PVC blends during crystallization of PCL. For a given blend composition, the segregation distance of PVC during recrystallization of PCL after SCF CO2 treatments is relatively high as compared with the blend before SCF CO2 treatments.