Liquid Crystalline Structure in Block Copolymers

Perforated layer structures in liquid crystalline rod-coil block copolymers.

We report a novel observation of the tetragonal perforated layer structures in a series of rod-coil liquid crystalline block copolymers (BCPs), poly(styrene-block-(2,5-bis[4-methoxyphenyl]oxycarbonyl)styrene) (PS-b-PMPCS). PMPCS forms rigid rods while PS forms the coil block. Differential scanning calorimetry (DSC), polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), wide-ang...

Surface Induced Tilt Propagation in Thin Films of Semifluorinated Liquid Crystalline Side Chain Block Copolymers

The supramolecular self-assembly within a liquid crystalline block copolymer thin film with mesogenic semifluorinated alkyl side groups was studied using both grazing incidence X-ray diffraction and small angle scattering. Previous studies employing near-edge X-ray absorption fine structure spectroscopy indicated that mesogens at the film surface are tilted relative to the surface-normal. This ...

Liquid Crystalline Gels by Self-Assembly of Triblock Copolymers

Crosslinkable liquid crystalline copolymers with variable isotropization temperature†

Main-chain liquid crystalline polymers were synthesized from diene mesogens using acyclic diene metathesis polymerization to control the thermal properties of an unsaturated polymer that may subsequently be crosslinked to form nematic networks. The mesogen homopolymer forms a nematic phase with a glass transition of 74 C and an isotropization temperature of 189 C. Copolymerizing the mesogenic m...

Synthesis and characterization of diblock copolymers based on crystallizable poly(3-caprolactone) and mesogen-jacketed liquid crystalline polymer block

Diblock copolymers comprising crystallizable poly(3-caprolactone) and poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PMPCS) were synthesized by ring-opening polymerization of 3-caprolactone and subsequent atom transfer radical polymerization (ATRP) of MPCS. The molecular structure of the copolymers was confirmed by H NMR spectroscopy and GPC. Kinetic study of ATRP showed that the polymeriz...