(Meth)acrylate liquid crystalline polymers for membrane applications

Abstract

Synthesis and characterization of a series of linear copolymers with liquid crystalline side chains is reported. Methacrylate monomers containing cyanobiphenyl as a mesogenic group were prepared. These monomers were then copolymerized with 2‐ethylhexyl acrylate in varying molar ratios. The structure and composition of the monomers and corresponding polymers were determined by 1H‐NMR, elemental analysis and size‐exclusion chromatography. Thermal properties of the polymers were studied using differential scanning calorimetry, polarized optical microscopy, and X‐ray scattering techniques. Increasing mesogen content resulted in an increase of the glass transition temperature of the copolymers. In addition, above a threshold mesogen content the copolymers exhibited smectic mesophases. Using a solution casting technique, a membrane was fabricated to study single gas transport behaviors. Permeabilities, were in the order of CO2 > propylene > O2 > N2 > CH4 > propane. Diffusion coefficients correlated well to Lenard–Jones Diameter. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42694.

Temperature-Dependent Gas Transport Behavior in Cross-Linked Liquid Crystalline Polyacrylate Membranes

“…Synthesis of the 11-(4-Cyanobiphenyl-4′-yloxy)undecyl methacrylate. The synthesis of the LC precursor 4′-(11-hydroxy-undecyloxy)-4-biphenylcarbonitrile and the polymerizable LC monomer 11-(4-cyanobiphenyl-4′-yloxy)undecyl methacrylate was performed using a two-step synthesis via a Williamson and esterification reaction and has been described in a previous publication [25].…”

Programmable liquid crystal elastomer matrix through photomechanical responses

“…Among light responsive materials, liquid crystal elastomer (LCE) is an ideal candidate to be used in a range of intelligent applications, which has intrinsic spontaneous orientation of liquid crystal in addition to their conventional high polymer properties . It is formed by flexible cross‐linked polymeric chains with rigid rod‐like mesogenic segments in the main chain or attached as side branches.…”

“…Among light responsive materials, liquid crystal elastomer (LCE) is an ideal candidate to be used in a range of intelligent applications, which has intrinsic spontaneous orientation of liquid crystal in addition to their conventional high polymer properties. [9,10] It is formed by flexible cross-linked polymeric chains with rigid rod-like mesogenic segments in the main chain or attached as side branches. Due to the special characteristics of liquid crystal mesogens, LCE is susceptible to a variety of external stimuli, such as heat, [11] electric, [12] light, [13] magnetic, [14] and so on.…”