A novel optically active diblock copolymer composed of poly(ethylene glycol) and poly [N-{o-(4-phenyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl}maleimide]: Synthesis, micellization behavior, and chiroptical property

作者：Lou Liping; Jiang Liming^*; Sun Weilin; Shen Zhiquan

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2008, 46(3): 1025-1033.

DOI：10.1002/pola.22445

• amphiphiles
• chiroptical property
• diblock copolymers
• micelles
• optical activity
• oxazoline
• poly(ethylene glycol){o-(4-phenyl-4,5-dihydro-1,3-oxazol-2-yl)-phenyl}maleimide

A series of optically active amphiphilic block copolymers were synthesized by using potassium alkoxide of poly(ethylene glycol) monomethyl ether (MeOPEGO(-)K(+)) to initiate the anionic polymerization of N-{o-(4-phenyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl}maleimide [(R)-PhOPMI]. The PEG-macroinitiators generated in situ in the reaction between MeOPEGOH and potassium naphthylide in tetrahydrofuran. The synthetic procedure may provide the PEG-b-PPhOPMI copolymers with well-defined structure, as evidenced by gel permeation chromatography, H-1 NMR, FTIR, and elemental analysis. In particular, the preparation of block copolymers having a laevorotation or dextrorotation activity was accomplished by changing the feed composition. The micellization was examined for the amphiphilic block copolymers in aqueous milieu by fluorescence spectroscopy, dynamic light scattering, and circular dichroism. The results indicate that the copolymers could form regular spherical micelles with core-shell structure when the hydrophilic component was long enough; in contrast, the copolymers containing shorter PEG segments formed aggregates in large dimension due to the considerable interaction between hydrophobic PPhOPMI components. Also, it was found that the aggregated structure of the polymeric micelles is strongly dependent on the medium nature and the polymer concentration.

• 出版日期2008-2-1
• 单位浙江大学