scholarly journals Fabrication and Characterization of Functional pH-Responsive Poly (S-Co-DEAMVA)-g-Tryptophan

Author(s):  
Momen S. A. Abdelaty

Vanillin was used to synthesize cationic monomers from the amine group with a tertiary amine. It has both an amine and an aldehyde group. For that, it helps graft to form Schiff base with amino acid-like tryptophan. It is abbreviated by {2-[(diethylamino) methyl]-4-formyl-6-methoxyphenyl acrylate} DEAMVA and evaluated by, e.g., 1H NMR, 13C NMR, and FT IR results were compared with the chemical structure elevated good agreement. 10 and 25 mol % of vanillin monomer was copolymerized with (S). The copolymers of poly (S-co-DEAMVA) were investigated by 1H NMR, FTIR, GPC, and DSC. The grafting with tryptophan has also been modified and exposed to the same investigation methods; further, UV/Vis spectroscopy has designated the pH responsiveness. The study aims to improve the general characterization of polystyrene and produce functional pH-responsive polymer for graft biological molecules in the future.

2012 ◽  
Vol 204-208 ◽  
pp. 4211-4214 ◽  
Author(s):  
Ye Wei Xu ◽  
Jie Tang ◽  
Guan Jun Chang ◽  
Fang Hua Zhu ◽  
Lin Zhang

Using 1,4-bis(2-benzimidazolyl) benzene (BBIB) and 4,4'-difluorobenzophenone as the monomers, poly(N-arylenebenzimidazole ketone) (PNABIK) has been prepared via the aromatic nucleophilic displacement reaction. The chemical structure of PNABIK was confirmed by FT-IR, elemental analysis and 1H NMR. The results show a good agreement with the proposed structures. The polymer was obtained in quantitative yields with Mn value 12500 and Mw value 28600, respectively. DSC and TGA measurements show that the glass transition temperature (Tg) is 202 °C and 5% weight loss temperature is 550°C in nitrogen and 571 °C in air, respectively. In addition, the novel polymer exhibit good solubility.


2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.


Author(s):  
G. Dayana Jeyaleela ◽  
S. Irudaya Monisha ◽  
J. Rosaline Vimala ◽  
A. Anitha Immaculate

Objective: Natural products from medicinal plants, either as isolated compounds or as standardized plant extracts exhibit promising source of medicinal activity against various diseases. The aim of the present work was to make an attempt of isolation of bioactive principle and characterization of the isolated compound, from the medicinal plant Melia dubaiMethods: The extraction was done by a cold percolation method and the compound was separated and isolated by chromatography technique such as a thin layer chromatography (TLC), column chromatography and high-performance liquid chromatography (HPLC). The isolated compound was crystallized and the structural characterization of the isolated compound was made using UV-Visible, FT-IR, 1H-NMR, GC-MS and MS techniques which confirmed the structure of the isolated compound.Results: The separated and isolated compound was characterized by both physical and spectral methods like Ultraviolet-Visible spectroscopy (UV-Visible), Fourier transform infrared spectroscopy (FT-IR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), Gas chromatography-mass spectrometry (GC-MS), and Mass spectrometry(MS). Based on the studies, organizational characteristics of one bioactive principle were deciphered. The results revealed that the isolated species is 2-chlorobenzimidazole and it agreed well with the reported value and spectra for 2-chlorobenzimidazole.Conclusion: The above results obtained in this research work clearly indicated the promising occurrence of 2-chlorobenzimidazole in Media dubia plant leaves. The future scope of these studies may guide us to view the biological activity of the isolated compound.


2016 ◽  
Vol 13 (4) ◽  
pp. 762-769
Author(s):  
Baghdad Science Journal

Various of 2,5- disubstituted 1,3,4-oxadiazole (Schiff base, ?- lactam and azo) were synthesized from 2,5-di (4,4?-amino-1,3,4-oxadiazole which usequently synth-esized from mixture of 4- amino benzoic acid and hydrazine arch of polyphosphorus acid. The synthesized compounds were cherecterized by using some spectral data (UV, FT-IR , and 1H-NMR)


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1498 ◽  
Author(s):  
Abdul Hafeez ◽  
Zareen Akhter ◽  
John F. Gallagher ◽  
Nawazish Ali Khan ◽  
Asghari Gul ◽  
...  

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.


2007 ◽  
Vol 124-126 ◽  
pp. 287-290 ◽  
Author(s):  
Fei Liu ◽  
Yong Jun He ◽  
Jeung Soo Huh

The nano-CeO2 was synthesized by two-step solid-phase reaction. The image of TEM showed that nano-CeO2 with an average size of about 70 nm. The series of polyaniline/nano-CeO2 composites with different PANi: CeO2 ratios were prepared by in-situ polymerization in the presence of hydrochloric acid (HCl) as dopant by adding nano-CeO2 into the polymerization reaction mixture of aniline. The composites obtained were characterized by FT-IR and UV-vis spectroscopy analysis. The FT-IR spectra of nanocomposites indicate different blue-shifts, attributed to C–N stretching mode for benzenoid unit. The UV-vis spectra of nanocomposites display einstein-shifts compared with PANi at 620nm. The conductivity properties of the composites are also changed compare to the pure PANi. These results suggest that the interactions between the polymer matrix and nanoparticles take place in polyaniline/nano- CeO2 composites.


2011 ◽  
Vol 396-398 ◽  
pp. 1518-1522
Author(s):  
Feng Ding ◽  
Da Zhi Wang ◽  
Shao Yin Zhang ◽  
Tian Xing Liu

A low expense chloro-monomer, 1-(4'-chloro-1-benzoyl)-3-(4'-1-choro-benzene sulfonyl)-benzene(CBCBSB), was synthesized by the Friedel-Crafts reaction of m-chlorosu1fonyl benzoyl chloride with chlorobenzene. A novel poly (aryl ether sulfone ketone)s (PAESK) containing m-sulfonylbenzoyl linkages in the main chains were prepared by copolycondensation of CBCBSB with hydroquinone in N, N-Dimethylacetamide (DMAc). The structure of PAESK was confirmed by FT-IR, 1H-NMR and characterized by XRD. thermogravimetry (TG) and Differential Scanning Calorimeter (DSC) were carried out to demonstrate its good melt processability. The polymer exhibited the better solubility in chloroform, N-methyl-2-pyrrlidone(NMP), dimethylacetamide(DMAC), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) and excellent mechanical performance.


2011 ◽  
Vol 399-401 ◽  
pp. 359-362 ◽  
Author(s):  
Yi Chun Wang ◽  
Zheng Wei Dai ◽  
Yuan Xue

Thermo-sensitive polyurethane (TSPU) was synthesized from poly(ε-caprolactone) and 4,4’-methylenebis (phenyl isocyanate) by a two-step process with 1,4-butanediol as the chain extender. Following that, a novel temperature-sensitive material was created by the strategy of IPN from TSPU and PNIPAAm in the method of in situ polymerization. The chemical structure and thermo properties of the semi-IPN were characterized with FT-IR and DSC. The results prove that intensive inter-molecular interactions exist between TSPU and PNIPAAm chains, which have significant influence on the phase transition behaviors of the material. According to these results, the transition temperature of the semi-IPN can be adjusted in the range of 30~40 °C by controlling the composition of TSPU and the semi-IPNs.


Sign in / Sign up

Export Citation Format

Share Document