Synthesis of Temperature Sensitive Copolymers In Supercritical Carbon Dioxide

• Main Authors: Siou-Huei Huang, 黃綉惠
• Other Authors: Yan-Ping Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/45072063152440764984

碩士 === 國立臺灣大學 === 化學工程學研究所 === 98 === In recent years, the intelligent materials with biodegradable have been employed in research and development for the drug delivery and biological processes. Supercritical fluid technology has the advantages of reducing significantly the amount of solvent in traditional process. It can also avoid the oxidation of initiators, and simplify the following separation steps. In this research we synthesize the temperature sensitive materials by using the supercritical carbon dioxide to protect the environment. Poly(N-isopropylacylamide), PNIPAAm, is a thermoresponsive polymer that has lower critical solution temperature(LCST) around 31~32 ℃ in aqueous solution. In this study, PNIPAAm copolymers with hydrophilic comonomers, Methacrylic acid (MAA) and N-Methyl-N-vinylacetamide (MVA), were synthesized in order to obtain copolymers with LCST slightly higher than the physiological temperature(37 ℃), as required by a drug delivery concept. The two copolymers, P(NIPAAm-co-MAA) and P(NIPAAm-co-MVA), were examined using FTIR to confirm their chemical structures. In UV analysis, we found that only the LCST of P(NIPAAm-co-MVA) could be promoted to around 37 ℃ in aqueous solution. However the LCST of P(NIPAAm-co-MAA) can be increased in base solution (pH=8.67). In TGA analysis, the thermal stability of copolymers can be observed. In SEM images, We observed that the particle size of two copolymers all became smaller by adding the crosslinkers, and the particle size of P(NIPAAm-co- MAA) can be reduced to 0.068µm by increasing the amount of MAA.