scholarly journals Study of the influence of preparation parameters on sorption properties of porous collagen material

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 177-179
Author(s):  
O. K. Molokanova ◽  
◽  
S. A. Shirokikh ◽  
E. S. Vainerman ◽  
M. Yu. Koroleva ◽  
...  

In this work, the dependences of the sorption properties of the porous polymeric materials prepared from the cross- linked collagen on their composition and process specifications were studied. The optimal concentration of glutaraldehyde as a cross-linking agent was 0.5 wt %, the mass ratio of fish and leather waste was 1:1, and the drying temperature was 25 °C. Sorbent samples prepared using optimal parameters were effective in the sorption of petroleum products.

2002 ◽  
Vol 32 (2b) ◽  
pp. 523-530 ◽  
Author(s):  
D. T. Dias ◽  
A. N. Medina ◽  
M. L. Baesso ◽  
A. C. Bento ◽  
M. F. Porto ◽  
...  

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Malgorzata Latos-Brozio ◽  
Anna Masek ◽  
Małgorzata Piotrowska

(+)-Catechin is a flavonoid with valuable antioxidant and antimicrobial properties, found in significant amounts in green tea leaves. Polymeric forms of catechin have been obtained by enzymatic reaction, photopolymerization, and polycondensation in designed processes. However, so far, poly(catechin) has not been received in the cross-linking reaction. Reactions with the cross-linking compound allowed for the preparation of antibacterial and antioxidant materials based on quercetin and rutin. The aim of the research was to obtain, for the first time, poly(catechin) by reaction with glycerol diglycide ether cross-linking compound. The polymeric form of (+)-catechin was confirmed using FTIR and UV-Vis spectroscopy. In addition, thermal analysis (TG and DSC) of the polymeric catechin was performed. The antioxidant and antibacterial activity of poly (flavonoid) was also analyzed. Poly(catechin) was characterized by greater resistance to oxidation, better thermal stability and the ability to reduce transition metal ions than (+)-catechin. In addition, the polymeric catechin had an antimicrobial activity against Staphylococcus aureus stronger than the monomer, and an antifungal activity against Aspergillus niger comparable to that of (+)-catechin. The material made on the basis of (+)-catechin can potentially be used as a pro-ecological stabilizer and functional additive, e.g., for polymeric materials as well as dressing materials in medicine.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 608-624 ◽  
Author(s):  
Gang Zhou ◽  
Tao Fan ◽  
Mao Xu ◽  
Han Qiu ◽  
Jiayuan Wang ◽  
...  

This paper proposes the development of a novel coagulant for dust suppression in open-cast mines. Specifically, pretreated sodium lignin sulfonate and acrylic acid were first cross-linked, then the graft copolymerization of the intermediate product (the cross-linking product) and acrylamide was conducted and finally the resulting gelatinous substances were crushed. During the reaction process, N,N’-methylene-bis-acrylamide and ammonium persulfate were used as the cross-linking agent and initiator, respectively. Subsequently, the functional groups, crystalline structure, and thermal stability of the dust coagulant were examined by means of Fourier transform infrared spectra measurements, X-ray diffraction spectra measurements, and differential scanning calorimeter analysis. Moreover, single-factor experiments were conducted to explore the optimal synthesis condition. According to the experimental results, the coagulant achieved its optimal dust suppression performance under the following conditions: the mass ratio of lignin to acrylic acid was 1:3, the mass ratio of lignin to acrylamide was 2:7, the content of the cross-linking agent was 0.9%, the mass ratio of initiator to acrylamide was 2:100, the reaction temperature was set as 60℃, and the pH value was set as 7. Finally, the coagulant was measured for its swelling kinetics, viscosity, film-forming hardness, peeling strength, and ability to suppress dust. It can be concluded that the coagulant exhibits a very high standard of both dust suppression and wind resistance.


Author(s):  
Yury N. Rybakov ◽  
◽  
Alexander V. Dedov ◽  
Sergey V. Larionov ◽  
◽  
...  

Author(s):  
Istebreq A. Saeedi ◽  
Sunny Chaudhary ◽  
Thomas Andritsch ◽  
Alun S. Vaughan

AbstractReactive molecular additives have often been employed to tailor the mechanical properties of epoxy resins. In addition, several studies have reported improved electrical properties in such systems, where the network architecture and included function groups have been modified through the use of so-called functional network modifier (FNM) molecules. The study reported here set out to investigate the effect of a glycidyl polyhedral oligomeric silsesquioxane (GPOSS) FNM on the cross-linking reactions, glass transition, breakdown strength and dielectric properties of an amine-cured epoxy resin system. Since many previous studies have considered POSS to act as an inorganic filler, a key aim was to consider the impact of GPOSS addition on the stoichiometry of curing. Fourier transform infrared spectroscopy revealed significant changes in the cross-linking reactions that occur if appropriate stoichiometric compensation is not made for the additional epoxide groups present on the GPOSS. These changes, in concert with the direct effect of the GPOSS itself, influence the glass transition temperature, dielectric breakdown behaviour and dielectric response of the system. Specifically, the work shows that the inclusion of GPOSS can result in beneficial changes in electrical properties, but that these gains are easily lost if consequential changes in the matrix polymer are not appropriately counteracted. Nevertheless, if the system is appropriately optimized, materials with pronounced improvements in technologically important characteristics can be designed.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik

Polymer–clay mineral composites are an important class of materials with various applications in the industry. Despite interesting properties of polysiloxanes, such matrices were rarely used in combination with clay minerals. Thus, for the first time, a systematic study was designed to investigate the cross-linking efficiency of polysiloxane networks in the presence of 2 wt % of organo-montmorillonite. Montmorillonite (Mt) was intercalated with six quaternary ammonium salts of the cation structure [(CH3)2R’NR]+, where R = C12, C14, C16, and R’ = methyl or benzyl substituent. The intercalation efficiency was examined by X-ray diffraction, CHN elemental analysis, and Fourier transform infrared (FTIR) spectroscopy. Textural studies have shown that the application of freezing in liquid nitrogen and freeze-drying after the intercalation increases the specific surface area and the total pore volume of organo-Mt. The polymer matrix was a poly(methylhydrosiloxane) cross-linked with two linear vinylsiloxanes of different siloxane chain lengths between end functional groups. X-ray diffraction and transmission electron microscopy studies have shown that the increase in d-spacing of organo-Mt and the benzyl substituent influence the degree of nanofillers’ exfoliation in the nanocomposites. The increase in the degree of organo-Mt exfoliation reduces the efficiency of hydrosilylation reaction monitored by FTIR. This was due to physical hindrance induced by exfoliated Mt particles.


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