Synthesis and self‐association behavior of poly[bis(2‐(2‐methoxyethoxy)ethoxy)phosphazene]‐b‐poly(propyleneglycol) triblock copolymers |
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Authors: | Youngkyu Chang Song Yun Cho Lee B Steely Harry R Allcock |
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Institution: | Department of Chemistry, The Pennsylvania State University, 104 Chemistry Research Building, University Park, Pennsylvania 16802 |
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Abstract: | Amphilic triblock copolymers with varying ratios of hydrophilic polybis (methoxyethoxyethoxy)phosphazene] (MEEP) and relatively hydrophobic poly(propylene glycol) (PPG) blocks were synthesized via the controlled cationic‐induced living polymerization of a phosphoranimine (Cl3P?NSiMe3) at ambient temperature. A PPG block can function as either a classical hydrophobic block or a less hydrophobic component by varying the nature of a phosphazene block. The aqueous phase behavior of MEEP‐PPG‐MEEP block copolymers was investigated using fluorescence techniques, TEM, and dynamic light scattering (DLS). The critical micelle concentrations (cmcs) of MEEP‐PPG‐MEEP block copolymers were determined to be in the range of 3.7–16.8 mg/L. The mean diameters of MEEP‐PPG‐MEEP polymeric micelles, measured by DLS, were between 31 and 44 nm. The equilibrium constants of pyrene in these micelles ranged from 4.7 × 104 to 9.6 × 104. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 692–699, 2009 |
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Keywords: | amphiphilic triblock copolymers block copolymers cationic polymerization cationic‐induced living polymerization hydrophilic poly[bis(methoxyethoxyethoxy) phosphazene] hydrophobic poly(propylene glycol) micelles polyphosphazenes |
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