Synthesis and characterization of new Schiff base ester liquid crystals with fatty acids from palm oil as flexible alkyl chain

2021 ◽  
Vol 170 ◽  
pp. 113808
Author(s):  
Weng Nam Lee ◽  
Noordini M. Salleh ◽  
Sit-Foon Cheng
2011 ◽  
Vol 364 ◽  
pp. 95-99 ◽  
Author(s):  
S.C. Goh ◽  
S.Y. Chin ◽  
L.M.S. Lee ◽  
Mohd Ambar Yarmo ◽  
N.I. Nik Yusof

In this research, new chemistry is explored through a simple, efficient and cheap method to synthesize new surfactants from palm oil fatty acids. Oleic acid, which is one of the major fatty acids in palm oil, has been used as a starting material for the synthesis of surfactants. This study focuses on the synthesis and characterization of bolaform surfactants from oleic acid. For this purpose, two steps reaction will be carried out: Firstly, consisted of hydrobromination of oleic acid followed by reaction of 10-bromo-octadecanoic acid with ethane-1,2-dithiol and butane-1,2-dithiol. During the first stage of the reaction, hydrobromination of oleic acid was carried out by adding hydrobromic acid into the oleic acid. The reaction was carried out in benzene as solvent at 30°C and atmospheric pressure. This reaction gives 73% yield of 10-bromo-octadecanoic acid and it yield a black brownish liquid which have the m/z 363.2056 by ESI-MS(ToF) and –CH2-CHBr-CH2-shift (4.02 ppm) was well defined in1H-NMR. The separation of 10-bromo-octadecanoic acid was done through thin layer chromatography (TLC) with chloroform and methanol as the eluent and silica plate grade 60 F254as the stationary phase. The second stage of reaction was reacting the 10-bromo-octadecanoic acid with ethane-1,2-dithiol and butane-1,2-dithiol in THF as the solvent and 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU) as the catalyst respectively. These reactions were carried out at 30°C and atmospheric pressure. Product obtained was a two layers black brownish liquid with white colour precipitate gives m/z: 659.4813 for ethane-1,2-dithiol and m/z:686.5278 for butane-1,4-dithiol respectively using ESI-MS (ToF) mass spectroscopy. Separation was done on both bolaform surfactants through thin layer chromatography (TLC) with hexane and ethyl acetate as eluent and silica plate grade 60 F254as stationary phase, and finally followed by column chromatography. These two new surfactants will be tested for their physical-chemical properties as well as apply on nanomaterial stabilizer.


2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 785
Author(s):  
Veridiana G. Guimarães ◽  
Anastasiia Svanidze ◽  
Tianyi Guo ◽  
Pawan Nepal ◽  
Robert J. Twieg ◽  
...  

Cholesteric liquid crystals are frequently produced by the addition of chiral dopants to achiral nematic hosts. We report here the synthesis and performance of chiral dopants obtained from bio-betulin produced by a fermentation process. An important aspect of this work is to point out that the fermentation process used to obtain the starting materials is much easier and cheaper when carried out in large volumes than isolating it from the natural product. The performance of the dopants obtained from bio-betulin is indistinguishable from those obtained from commercially available synthetic betulin.


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