scholarly journals Synthesis, characterization, thermal stability and antibacterial activity of coumarin based methacrylate copolymers

2014 ◽  
Vol 32 (10) ◽  
pp. 1373-1380 ◽  
Author(s):  
S. Venkatesan ◽  
B. Ranjithkumar ◽  
S. Rajeshkumar ◽  
K. Anver Basha
e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 673-681
Author(s):  
Yanchao Qiao ◽  
Lijie Duan

AbstractAntibacterial materials have found widespread interest in different fields nowadays. In this study, curcumin (Cur) was incorporated into the polyvinyl butyral (PVB) matrix by dissolving in ethanol for improving the functional properties of a pure PVB film. We found that Cur was uniformly dispersed in the PVB matrix, which showed good compatibility. Moreover, the incorporation of Cur could also improve thermal stability, hydrophilicity, and mechanical property. The UV-vis spectra of the PVB–Cur film demonstrated that the film could block ultraviolet radiation. Subsequently, the antibacterial activity of the PVB–Cur film was measured by the colony-counting method against S. aureus and E. coli. The results showed that the PVB–Cur film exhibited good antibacterial activity. Therefore, the PVB–Cur film was considered as a promising material for food and medical packaging applications.


2018 ◽  
Vol 10 (7) ◽  
pp. 6137-6145 ◽  
Author(s):  
Ding-Yi Fu ◽  
Simin Zhang ◽  
Zhiyu Qu ◽  
Xianghui Yu ◽  
Yuqing Wu ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Narendra Kumar Chaudhary ◽  
Parashuram Mishra

A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate and nicotinaldehyde. The metal complexes of Co+2, Ni+2, Cu+2, and Zn+2 were characterized and investigated by physical and spectral techniques, namely, elemental analysis, melting point, conductivity, 1H NMR, IR, UV-Vis spectra, ESR, SEM, and mass spectrometry measurements. They were further analyzed by thermal technique (TGA/DTA) to gain better insight about the thermal stability and kinetic properties of the complexes. Thermal data revealed high thermal stability and nonspontaneous nature of the decomposition steps. The Coats-Redfern method was applied to extract thermodynamic parameters to explain the kinetic behavior. The molar conductance values were relatively low, showing their nonelectrolytic nature. The powder XRD pattern revealed amorphous nature except copper complex (1c) that crystallized in the triclinic crystal system. The EPR study strongly recommends the tetrahedral geometry of 1c. The structure optimization by MM force field calculation through ArgusLab 4.0.1 software program supports the concerned geometry of the complexes. The in vitro antibacterial activity of all the compounds, at their two different concentrations, was screened against four bacterial pathogens, namely, E. coli, P. vulgaris, K. pneumoniae, and S. aureus, and showed better activity compared to parent drug and control drug.


2019 ◽  
Vol 140 (1) ◽  
pp. 189-198 ◽  
Author(s):  
Marta Worzakowska

Abstract The thermal properties together with the identification of the emitted volatiles during heating of the starch-graft-poly(geranyl methacrylate) copolymers with the use of a TG/FTIR-coupled method and some of the physicochemical properties of the copolymers were determined. It was found that the use of the geranyl methacrylate monomer to the graft copolymerization with potato starch allowed to replace ca. 1.46 hydroxyl groups per glycosidic units of starch macromolecule by the poly(geranyl methacrylate) chains under the optimal reaction conditions. Generally, all tested starch graft copolymers exhibited a significant increase in polar solvent resistance, moisture resistance and chemical stability as compared to potato starch. However, the thermal stability of the obtained materials was substantially lower as compared to the thermal stability of potato starch. The beginning of the decomposition of the copolymers was observed below 150 °C. It was due to low thermal stability of the poly(geranyl methacrylate) chains. The decomposition of the prepared materials runs at least four, unseparated stages. The first stage was visible up to 220–240 °C. It was connected with the emission of some aldehyde, acid, alcohol, alkene, ester fragments, H2O and CO2 as a result of the depolymerization, destruction and partial decarboxylation of the poly(geranyl methacrylate) chains. The second stage was spread between ca. 220–240 and 358–375 °C. The emission of organic, saturated, unsaturated, aromatic, oxygen-rich fragments, CO, CO2 and H2O as a result of the decomposition and dehydration of starch was confirmed. Heating of the studied materials between 358–375 and 455–477 °C resulted in subsequent decomposition processes of the residues and the creation of some oxygen-rich saturated and unsaturated fragments, CO, CO2, H2O and CH4. Finally, above 455–477 °C, a minor mass loss as a result of the decomposition processes of the residues formed before was observed. The emission of CO, CO2, H2O, CH4 and some oxygen-rich saturated and unsaturated fragments was confirmed.


2021 ◽  
Vol 21 (10) ◽  
pp. 5120-5130
Author(s):  
Hui Long ◽  
Wei-Cong Kuang ◽  
Shi-Liang Wang ◽  
Jing-Xian Zhang ◽  
Lang-Huan Huang ◽  
...  

Poly(cyclotriphosphazene-co-4,4’-diaminodiphenyl ether) (PPO) microspheres were prepared via a precipitation polymerization method, using hexachlorocyclotriphosphazene (HCCP) and 4,4’-diaminodiphenyl ether (ODA) as monomers. Silver-loaded PPO (PPOA) microspheres were generated by the in situ loading of silver nanoparticles onto the surface by Ag+ reduction. Our results showed that PPOA microspheres were successfully prepared with a relatively uniform distribution of silver nanoparticles on microsphere surfaces. PPOA microspheres had good thermal stability and excellent antibacterial activity towards Escherichia coli and Staphylococcus aureus. Furthermore, PPOA microspheres exhibited lower cytotoxicity when compared to citrate-modified silver nanoparticles (c-Ag), and good sustained release properties. Our data indicated that polyphosphazene-based PPOA microspheres are promising antibacterial agents in the biological materials field.


2013 ◽  
Vol 750-752 ◽  
pp. 1609-1612 ◽  
Author(s):  
Yang Ti ◽  
Jian Ru Wu ◽  
Da Jun Chen

In this paper, Fe-OCAP/PU blends were prepared. The mechanical properties and thermal stability of the samples were studied by tensile tests and thermogravimetric analysis, respectively. Results showed that the mechanical properties and thermal stability of the samples were improved with the increase of Fe-OCAP content. The antibacterial property of Fe-OCAP and Fe-OCAP/PU films was investigated by agar diifusion method and shake flask method, respectively. Fe-OCAP and Fe-OCAP/PU films showed efficient antibacterial activity againstS.aureus.


BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 415-428
Author(s):  
Qiyuan Chen ◽  
Shengling Xiao ◽  
Sheldon Q. Shi ◽  
Liping Cai

A water and organic soluble N-benzyl-N,N-diethyl quaternized chitosan (NSQC) material was synthesized using chitosan, benzaldehyde, and bromoethane. Amino groups on chitosan reacted with benzaldehyde to form a Schiff base intermediate. Quaternized chitosan was obtained by reacting the Schiff base with bromoethane. The quaternized chitosan was dissolved in an organic solution with dissolved cellulose and cast to prepare quaternized chitosan/cellulose (QCC) film. The molecular structure, morphology, tensile strength, thermal stability, and antibacterial activity effects of NSQC-treated cellulose film were studied in detail. The results showed that the NSQC product exhibited superior solubility in deionized water and dimethylacetamide. The addition of NSQC as a reinforcing agent in QCC film enhanced the interlinking of fibers and slowed down the rate of cellulose pyrolysis, which improved the tensile properties and thermal stability of the cellulose film. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of NSQC showed that it had good antibacterial activity against Staphylococcus aureus and Escherichia coli. The QCC film also showed contact sterilization ability with regards to two kinds of bacteria, which suggested that QCC film has the potential for applications in food packaging and bacterial barriers.


2020 ◽  
pp. 1298-1306
Author(s):  
Seenaa I. Hussein

     In this research, we prepared a polymer blend of polyvinylalcohol (PVA)/carrageenan/kaolinite by means of the solution cast approach. The composition of the blend was PVA in 1 gm by weight with 0.2 gm carrageenan as a plasticizer. The ratio of nanoclay varied between 1 and 5 wt%. Different properties were investigated in this study such as water vapor permeability, hardness, tear strength, color stability, thermal stability, and antibacterial activity. Water vapor permeability was decreased with increasing the ratio of nanoclay, while the values of hardness, tear strength, color stability, and thermal stability were increased. Also, the antibacterial activity examination with two types of bacteria, e.g. Gram positive (Staphylococcus aureus) and Gram negative (Klebsiella pneumonia), showed inhibition zone diameter which was increased with increasing nanoclay ratio. Moreover, it was found that nanoclay has the ability to kill both Gram positive and negative kinds of bacteria. It was found that the preparation of such films is suitable for food packaging.    


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