Abstract
Summary: Poly(ethylene oxide)s containing decylthiomethyl (DTP), decylsulfonylmethyl (DSP), methylโoligo(ethylene oxide) thiomethyl (M__n__OTP), methylโoligo(ethylene oxide) sulfonylmethyl (M__n__OSP), decylโoligo(ethylene oxide) thiomethyl (D__n__OTP), and decylโoligo(ethylene oxide) sulfonylmethyl (D__n__OSP) groups in the sideโchains, where n (the number of ethylene oxide units)โ=โ1, 2, 3, or 4 for D__n__OTP and D__n__OSP, and nโ=โ2, 3, or 7 for M__n__OTP and M__n__OSP, were synthesized to study the effect of the structure of the sideโchains on the ordered phases of the polymers. All of the M__n__OSPs, as well as M2OTP and M3OTP, were found to be amorphous polymers. DTP, M7OTP, D1OTP, D2OTP, and D3OTP showed crystalline phases below their isotropic temperatures. DSP, D1OSP, D2OSP, D3OSP, D4OSP, and D4OTP were found to be liquid crystalline. Therefore, the phase separation facilitated by the introduction of the sulfone group and/or by the addition of the longer ethylene oxide units between the ethylene oxide backbones and the hydrophobic decyl tails was found to be a key factor in the formation of the liquid crystalline phases. These ordered phases were characterized using differential scanning calorimetry, polarized optical microscopy, and Xโray diffraction.
Schematic illustration of the structures of poly(ethylene oxide) brushes showing liquid crystalline phases.
imageSchematic illustration of the structures of poly(ethylene oxide) brushes showing liquid crystalline phases.