Controlling lower critical solution temperatures of N-isopropylacrylamide-co-acrylic acid copolymers

• Main Authors: CHI-HWA CHEN, 陳祺華
• Other Authors: 呂幸江
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/41745738688022874061

碩士 === 長庚大學 === 化工與材料工程研究所 === 95 === The objective of this research was to adjust the lower critical solution temperature (LCST) of poly (N-isopropylacrylamide)(PNIPAAm) copolymer hydrogel containing different amounts of acrylic acid (AAc) through free-radical polymerization. The resulting NIPAAm-co-AAc copolymers were grafted to a isopore polycarbonate membrane to prepare composite membranes. DSC analysis was used to illustrate the LCST changes for hydrogel. The water swelling ratio at various temperatures and pH values were determined to confirm the thermo- and pH- responses of the hydrogels. The grafting yield and membrane thickness increased with AAc content in composites. The characteristic functional groups of AAc were observed using FTIR. The swelling ratio increased and the contact angle decreased with AAc due to its hydrophilic nature. The water permeability and drug 4-acetamidophenol release permeability increased as a function of temperature. All the experiments showed that the LCST was increased with AAc contect. The hydrogel consisting of 1.7 gram and 0.02 microliter AAc showed an LCST around 37℃. Furthermore, the permeability on-off ratio of the composites was higher at higher AAc concentration. In conclusion, the composite membranes offer potential for drug controlled applications.