Comparison of Thermoresponsive Deswelling Kinetics of Poly(oligo(ethylene oxide) methacrylate)-Based Thermoresponsive Hydrogels Prepared by 鈥淕raft-from鈥?ATRP

详细信息    查看全文

• 作者：Jeong Ae Yoon ; Tomasz Kowalewski ; Krzysztof Matyjaszewski
• 刊名：Macromolecules
• 出版年：2011
• 出版时间：April 12, 2011
• 年：2011
• 卷：44
• 期：7
• 页码：2261-2268
• 全文大小：936K
• 年卷期：v.44,no.7(April 12, 2011)
• ISSN：1520-5835

文摘

Cross-linked thermoresponsive poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene oxide) methyl ether methacrylate-co-2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) hydrogels (poly(MEO₂MA鈭扥EOMA鈭扝EMA hydrogels) were prepared by atom transfer radical polymerization (ATRP). The hydroxyl groups in the formed gel networks were transformed to ATRP initiating sites containing 2-bromoisobutyrate groups, and the modified gels were used as macroinitiators for 鈥済raft-from鈥?ATRP of MEO₂MA and OEOMA. The thermoresponsive properties of the resulting comb-type grafted hydrogels were compared to their unmodified precursor hydrogels with respect to the transition temperatures and deswelling rates. The thermoresponsive properties could be customized by changing the grafting density, grafted chain length, and the chain composition. Furthermore, the deswelling kinetics of the prepared hydrogels were quantitatively analyzed by exponential fitting of water retention with time. This analysis demonstrated that the grafted chains accelerated the hydrogel deswelling by providing a faster collapse to the globular structures, as assessed by much shorter water retention times for the grafted gels (<1/3 of the precursor gel retention time).