Kobayashi Yumi, Kitazawa Yuzo, Komori Takahiro, Ueno Kazuhide, Kokubo Hisashi, Watanabe Masayoshi
Department of Chemistry & Biotechnology, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan.
Macromol Rapid Commun. 2016 Jul;37(14):1207-11. doi: 10.1002/marc.201600137. Epub 2016 May 4.
Here the thermoresponsive self-assembly of diblock copolymers comprising poly(ethyl glycidyl ether) (PEGE) and poly(ethylene oxide) (PEO) in water and ionic liquids (ILs) is investigated. PEGE undergoes lower critical solution temperature (LCST) phase separation in both water and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2 mim][NTf2 ]), while PEO is a compatible segment for these solvents. The diblock copolymers, PEGE-b-PEO, undergo thermosensitive unimer-micelle transitions at temperatures close to the LCST point (TLCST ) of the PEGE homopolymer in water but not in [C2 mim][NTf2 ], even at temperatures much higher than TLCST . The difference in the thermoresponsivity of these solutions is explored using differential scanning calorimetry results from rather small magnitudes of the thermodynamic parameters for the phase transition of the PEGE segment in [C2 mim][NTf2 ], compared with those in water. Due to such small magnitudes, TLCST of the PEGE segment for the block copolymers in the IL is greatly affected by the elongation of soluble PEO segments.
在此，我们研究了由聚（乙基缩水甘油醚）（PEGE）和聚环氧乙烷（PEO）组成的二嵌段共聚物在水和离子液体（ILs）中的热响应性自组装。PEGE在水和1-乙基-3-甲基咪唑双（三氟甲磺酰）酰胺（[C2mim][NTf2]）中都会发生下临界溶液温度（LCST）相分离，而PEO是这些溶剂的相容链段。二嵌段共聚物PEGE-b-PEO在水中接近PEGE均聚物的LCST点（TLCST）的温度下会发生热敏性单分子-胶束转变，但在[C2mim][NTf2]中则不会，即使在远高于TLCST的温度下也是如此。通过差示扫描量热法研究了这些溶液热响应性的差异，结果表明，与在水中相比，PEGE链段在[C2mim][NTf2]中相变的热力学参数幅度较小。由于幅度如此之小，IL中嵌段共聚物的PEGE链段的TLCST受到可溶性PEO链段伸长的极大影响。
