83847-14-7

Usage

Synthesis

The target monomer was prepared by firstly converting the acid into the corresponding acid chloride, then condensing this withp-cyanophenol. The acid (17.32 g, 0.059 mol) was stirred with thionyl chloride (35.7 g, 0.3 mol) in the presence of DMF (2 drops) and 2,6-di-tert-butyl-4-methyl phenol (4.4 g, 0.02 mol). After ca. 25 min, by which time solution was achieved, the excess thionyl chloride was removed by rotary evaporation and high vacuum (1-2 h). The acid chloride residue was dis- solved in anhydrous chloroform (30 mL), then added slowly dropwise into a stirred solution of p-cyanophenol (7.03 g, 0.059 mol) and triethylamine (6.07 g, 0.06 mol) in chloroform (20 mL) at 0°C. After the addition the mixture was stirred at room temperature for 24 h and then chloroform (200 mL) added. This solution was washed with water (50 mL) followed by 2 N sodium hydroxide solution (3 x 50 mL) and water (2 x 50 mL). The organic layer was dried (MgSO,), evaporated, then subjected to flash chromatography, using dichloro- methane as both the solvent and the eluant. The monomer was finally recrystallized from isopropanol and shown to be pure by tlc. Yield: 16 g, 69%.

Upstream product

• 767-00-0 4-cyanophenol 
• 83883-26-5 4-{[6-(acryloyloxy)hexyl]oxy}benzoic acid 
• 2009-83-8 6-chloro-1-hexanol 
• 99-96-7 4-hydroxy-benzoic acid 
• 83883-25-4 4-(6-hydroxyhexyloxy)benzoic acid 

Relevant academic research and scientific papers

Photoorientation in hydrogen-bonded blends of liquid-crystalline polymers with a low-molecular photochromic dopant

A series of hydrogen-bonded blends of nematic liquid-crystalline copolymers with a low-molecular photochromic dopant and their covalent analogs were prepared. Their phase behavior and photooptical properties were studied. The introduction of a dopant increases considerably the isotropization temperatures of the systems. A comparative study of photoorientation processes in the blends and copolymers analogous to them was carried out. The induced dichroism in covalent systems is more pronounced than in similar hydrogen-bonded blends.

Optical properties of side-chain liquid crystal copolymers of monosubstituted cholesteryl itaconate and a non-chiral mesogen

New mono- and disubstituted cholesteryl derivatives of itaconic acid have been prepared and their thermotropic liquid crystalline behaviour examined.The monosubstituted derivative has been homopolymerized, and also copolymerized with a non-chiral mesogen 4-cyanophenyl-4'-(6-acryloyloxyhexyloxy) benzoate.Examination of the series of copolymers prepared, using differential scanning calorimetry and hot-stage polarizing microscopy, showed that when the content of the cholesteryl itaconate was high, both a smectic-A phase (SA) and a cholesteric phase (N*) were present.It was found that the SA phase could be eliminated by lowering the content of the cholesteryl itaconate in the copolymers, giving samples that displayed only the N* phase over a much wider temperature range.The samples in the N* phase also exhibited selective reflection of visible light that changed from short to long wavelengths as the samples were cooled from the isotropic melt.These colours can be locked into the glassy state of the polymer by quenching below the glass transition temperature, but only if the SA phase is absent.It was also noted that at high contents of the cholesteryl itaconate the selective reflection appears to occur in the ultraviolet region. - Keywords: itaconic acid; copolymers; liquid crystalline polymers; cholesteric phases; selective reflection