ATRP synthesis and association properties of thermoresponsive anionic block copolymers
ATRP synthesis and association properties of thermoresponsive anionic block copolymers
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温敏性阴离子嵌段共聚物的ATRP合成及缔合性能
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
V. Crescenzi
中科院分区：
文献类型：
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作者：
G. Masci;M. Diociaiuti;V. Crescenzi
采用原子转移自由基聚合（ATRP）方法制备了不同嵌段长度的2-丙烯酰胺-2-甲基丙磺酸钠（AMPS）和N-异丙基丙烯酰胺（NIPAAM）热敏性阴离子嵌段共聚物。通过使用 2-氯丙酸乙酯 (ECP) 作为引发剂和 CuCl/CuCl2/三(2-二甲基氨基乙基)胺 (Me6TREN) 催化体系在 DMF:水 50:50 (v/v) 混合物中于 20 °C 实现受控聚合。获得了36至98个重复单元的嵌段长度。通过动态光散射、荧光光谱和能量过滤透射电子显微镜研究了不同 NaCl 离子强度下水溶液中的缔合特性作为温度和聚合物浓度的函数。具有较高pNIPAAM/pAMPS比率的嵌段共聚物形成球形核-壳型胶束，与离子强度无关。具有较低pNIPAAM/pAMPS比例的嵌段共聚物在高离子强度下形成核壳型胶束。在低离子强度下观察到较大的颗粒，这可能是由于囊泡或复合胶束/胶束簇的形成所致。 © 2008 Wiley periodicals, Inc. J Polym Sci Part A：Polym Chem 46：4830–4842，2008
Thermosensitive anionic block copolymers of sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) and N-isopropylacrylamide (NIPAAM) with different block lengths were prepared by atom transfer radical polymerization (ATRP). Controlled polymerization was achieved by using ethyl 2-chloropropionate (ECP) as initiator and CuCl/CuCl2/tris(2-dimethylaminoethyl)amine (Me6TREN) catalytic system in DMF:water 50:50 (v/v) mixtures at 20 °C. Blocks lengths ranging from 36 to 98 repeating units were obtained. The association properties in aqueous solutions at different NaCl ionic strengths were studied as a function of temperature and polymer concentration by dynamic light scattering, fluorescence spectroscopy, and energy-filtered transmission electron microscopy. The block copolymers with a higher pNIPAAM/pAMPS ratio formed spherical core-shell type micelles independently of the ionic strength. The block copolymers with lower pNIPAAM/pAMPS ratio formed core-shell type micelles at high ionic strength. Larger particles were observed at low ionic strength, which could be due to the formation of vesicles or compound micelles/micellar clusters. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4830–4842, 2008