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Synthesis and Self‐Assembly Behavior of Organic–Inorganic Poly(ethylene oxide)‐ block ‐Poly(MA POSS)‐ block ‐Poly( N ‐isopropylacrylamide) Triblock Copolymers
Author(s) -
Zheng Yaochen,
Wang Lei,
Yu Rentong,
Zheng Sixun
Publication year - 2012
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201100506
Subject(s) - copolymer , atom transfer radical polymerization , dynamic light scattering , materials science , polymer chemistry , amphiphile , lower critical solution temperature , differential scanning calorimetry , polymerization , micelle , ethylene oxide , gel permeation chromatography , aqueous solution , macromonomer , chemical engineering , polymer , chemistry , organic chemistry , nanotechnology , nanoparticle , physics , engineering , composite material , thermodynamics
Abstract In this work, the synthesis of 3‐methacryloxypropylheptaphenyl POSS, a new POSS macromer (denoted MA‐POSS) is reported. The POSS macromer is used to synthesize PEO‐ b ‐P(MA‐POSS)‐ b ‐PNIPAAm triblock copolymers via sequential atom transfer radical polymerization (ATRP). The organic‐inorganic, amphiphilic and thermoresponsive ABC triblock copolymers are characterized by means of nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and atomic force microscopy (AFM) show that the hybrid ABC triblock copolymers are microphase‐separated in bulk. Cloud point measurements show that the effect of the hydrophiphilic block (i.e. PEO) on the LCSTs is more pronounced than the hydrophobic block (i.e. P(MA‐POSS)). Both transmission electron microscopy (TEM) and dynamic light scattering (DLS) show that all the triblock copolymers can be self‐organized into micellar aggregates in aqueous solutions. The sizes of the micellar aggregates can be modulated by changing the temperature. The temperature‐tunable self‐assembly behavior is interpreted using a combination of the highly hydrophobicity of P(MA‐POSS), the water‐solubility of PEO and the thermoresponsive property of PNIPAAm in the triblock copolymers.