scholarly journals Synthesis and Characterization of O-Acetyl-chitosan Acetic Ester

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Fangfang Cheng ◽  
Bingbing Wang ◽  
Yanzhi Xia

A novel amphipathic chitosan derivative, O-acetyl-chitosan acetic ester (ACHA), was synthesized by the reaction of chitosan with acetic acid in the presence of thionyl chloride. The physicochemical properties of ACHA were characterized by FTIR, 1H NMR, TGA, and XRD. The yield (Y) of ACHA was 79.4%, and the degree of acetylation (DA) of ACHA was 1.04. Compared to CS, ACHA could be dissolved in many organic solvents, deionized water, and aqueous solution. Our results showed that ACHA exhibited a superior antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. These findings indicated that ACHA was preferable for use as antimicrobial agents in wound healing, food preservative, and tissue engineering.

2019 ◽  
Vol 17 (3) ◽  
pp. 541-554
Author(s):  
Neeranuth Intakaew ◽  
Puracheth Rithchumpon ◽  
Chanatkran Prommin ◽  
Saranphong Yimklan ◽  
Nawee Kungwan ◽  
...  

New chiral derivatizing agents and the effect of aromatic rings were investigated for absolute configuration of chiral alcohols via1H-NMR.


e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 491-499
Author(s):  
Fukai Yang ◽  
Hao Yu ◽  
Yuyuan Deng ◽  
Xinyu Xu

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized soybean oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl alcohol, p-tert-butylphenol, and 4-methoxyphenol in the presence of tetrafluoroboric acid as the catalyst. The SOPs were characterized by FTIR, 1H NMR, GPC, viscosity, and hydroxyl numbers. Compared with ESO, the retention time of SOPs is shortened, indicating that the molecular weight of SOPs is increased. The structure of different monomers can significantly affect the hydroxyl numbers of SOPs. Due to the large steric hindrance of isoamyl alcohol, p-hydroxyanisole, and p-tert-butylphenol, SOPs prepared by these three monomers often undergo further dehydration to ether reactions, which consumes the hydroxyl of polyols, thus forming dimers and multimers; therefore, the hydroxyl numbers are much lower than polyol-E and polyol-P. The viscosity of polyol-E and polyol-P is much lower than that of polyol-I, polyol-B, and polyol-M. A longer distance between the molecules and the smaller intermolecular force makes the SOPs dehydrate to ether again. This generates dimer or polymers and makes the viscosity of these SOPs larger, and the molecular weight greatly increases.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.


2015 ◽  
Vol 19 (01-03) ◽  
pp. 335-343 ◽  
Author(s):  
Vicente M. Blas-Ferrando ◽  
Javier Ortiz ◽  
Fernando Fernández-Lázaro ◽  
Ángela Sastre-Santos

This work reports on the synthesis and characterization of a new gold nanoparticle-zinc phthalocyanine system, AuNP - S (t Bu )3 ZnPc , prepared by a ligand exchange reaction of tetraoctylammonium bromide with a novel unsymmetrically substituted zinc phthalocyanine which contains one thioester group in the peripheral position [ AcS (t Bu )3 ZnPc ]. The AuNP - S (t Bu )3 ZnPc hybrid was characterized using UV-vis and 1 H NMR spectroscopies. Transmission electron microscopy allowed the estimation of the size, which was calculated to be ~5 nm. AuNPs - S (t Bu )3 ZnPc conjugate showed much lower fluorescence quantum yield values than the AcS (t Bu )3 ZnPc demonstrating either an energy or electron transfer from the ZnPc to the AuNP . The AuNP - S (t Bu )3 ZnPc hybrid has been anchored to a TiO 2 semiconducting layer using lipoic acid. A solid configuration of TiO 2-lipoic acid- AuNP - S (t Bu )3 ZnPc has been prepared by anchoring lipoic acid to the TiO 2 ( TiO 2-LA) and introducing later the TiO 2-LA with free thiol groups in a toluene solution of AuNP - S (t Bu )3 ZnPc . We have also observed by UV-vis and fluorescence measurements the importance of the ZnPc in avoiding AuNP aggregation on the TiO 2 surface.


2011 ◽  
Vol 335-336 ◽  
pp. 989-993
Author(s):  
Mi Ouyang ◽  
Zhen Wei Yu ◽  
Yi Xu ◽  
Yu Jian Zhang ◽  
Cheng Zhang

Copolymers based on 1, 4-diethoxybenzene (DEB) and 3, 4-ethylenedioxythiophene (EDOT) were electrochemically synthesized and characterized. The structures of the copolymers were established by 1H NMR and FT-IR spectroscopy. The results indicated the final product was a copolymer instead of a blend or a composite. The physical properties were systematically investigated by cyclic voltammetry, UV-vis absorption and fluorescence. The PL maximum of copolymers presented obviously red-shift to long wavelength as the feed ratio of EDOT in monomer mixture increased.


Polymer ◽  
2011 ◽  
Vol 52 (25) ◽  
pp. 5764-5771 ◽  
Author(s):  
Li Qun Xu ◽  
Chao Huang ◽  
Rong Wang ◽  
Koon-Gee Neoh ◽  
En-Tang Kang ◽  
...  

1979 ◽  
Vol 34 (4) ◽  
pp. 579-584 ◽  
Author(s):  
Richard Ratka ◽  
Manfred L. Ziegler ◽  
Gerhard Schilling

Abstract The mechanism of formation of the exocyclic dimeric π-enyl complex (C8H13PdCl)2 by reaction of 1,3-dimethylenecyclohexane, C8H12 with trans-PdCl2(C6H5CN)2 is discussed. Through UV, 1H NMR (90 MHz, 360 MHz) and 13C spectroscopic studies it was possible to show that the dimer is formed by the disproportionate of C8H12 to C8H14 and m-xylene, and further that it consists of diastereomeric products. The reaction of (-) R-3-methyl-1-methylencyclohexane, C8H14, with the Pd-salt confirms that during the reaction between C8H12 and trans-PdCl2(C6H5CN)2 no free C8H14 is formed in solution.Studies on cleavage reactions of the dimer are also described in this paper.


2016 ◽  
Vol 13 (2) ◽  
pp. 244-252
Author(s):  
Baghdad Science Journal

In this paper, some chalcone derivatives (C1, C2) were synthesized based on the reaction of equal amount of substituted acetophenone and substituted banzaldehyde in basic medium. Oxazine and thiazine derivatives were prepared from the reaction of chalcones (C1-C2) with urea and thiourea respectively in a basic medium. Pyrazole derivatives were prepared based on the reaction of chalcones with hydrazine mono hydrate or phenyl hydrazine in the presence of glacial acetic acid as a catalyst. The new synthesized compounds were identified using various physical techniques like1 H-NMR and FT-IR spectra.


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