scholarly journals Thermally Stable and Antimicrobial Active Poly(Catechin) Obtained by Reaction with a Cross-Linking Agent

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Malgorzata Latos-Brozio ◽  
Anna Masek ◽  
Małgorzata Piotrowska
Keyword(s):  
Enzymatic Reaction ◽  
Antimicrobial Properties ◽  
Polymeric Materials ◽  
Transition Metal Ions ◽  
Cross Linking ◽  
Polymeric Form ◽  
Functional Additive ◽  
Vis Spectroscopy ◽  
Green Tea Leaves ◽  
The Cross

(+)-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.

scholarly journals Novel Polymeric Biomaterial Based on Naringenin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2142
Author(s):  
Malgorzata Latos-Brozio ◽  
Anna Masek ◽  
Małgorzata Piotrowska
Keyword(s):  
Antimicrobial Properties ◽  
Citrus Fruit ◽  
Polymeric Materials ◽  
Cross Linking ◽  
Plant Materials ◽  
Polymeric Form ◽  
Environmental Friendliness ◽  
Resistance To Oxidation ◽  
Raw Plant Materials ◽  
Polymeric Biomaterial

Biomaterials prepared based on raw plant materials are becoming more and more popular due to their specific properties and environmental friendliness. Naringenin is a flavonoid naturally occurring in citrus fruit with antioxidant and pharmacological activity. Polymeric materials based on flavonoids may have favorable properties in comparison to monomeric polyphenols, such as stronger antioxidant and antimicrobial properties. One of the methods of obtaining the polymeric form of flavonoids is polymerization with a cross-linking compound. This method has already been used to obtain poly(quercetin) and poly(rutin) from a flavonol group as well as poly(catechin) from the flavan-3-ol group of flavonoids. However, to date, no polymeric forms of flavanones have been prepared in a cross-linking reaction; the aim of this study was to obtain poly(naringenin) by reaction with a cross-linking compound using glycerol diglycide ether GDE. The degree of conversion of naringenin to poly(naringenin) determined by FTIR spectroscopy was 85%. In addition, the thermal, antioxidant and antimicrobial properties of poly(naringenin) were analyzed. Poly(naringenin) was characterized by greater resistance to oxidation and better thermal stability than monomeric naringenin. Moreover, polymeric naringenin also had a better ability to scavenge ABTS and DPPH free-radicals. In contrast to monomeric form, poly(naringenin) had antimicrobial activity against Candida albicans. Polymeric biomaterial based on naringenin could potentially be used as a natural stabilizer and antimicrobial additive for polymer compositions, as well as pro-ecological materials.

scholarly journals The photoacoustic spectroscopy applied in the characterization of the cross-linking process in polymeric materials

2002 ◽  
Vol 32 (2b) ◽  
pp. 523-530 ◽  
Author(s):  
D. T. Dias ◽  
A. N. Medina ◽  
M. L. Baesso ◽  
A. C. Bento ◽  
M. F. Porto ◽  
...  
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Polymeric Materials ◽  
Cross Linking ◽  
The Cross

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 ◽  
...  
Keyword(s):  
Polymeric Materials ◽  
Petroleum Products ◽  
Optimal Concentration ◽  
Sorption Properties ◽  
Cross Linking ◽  
Optimal Parameters ◽  
Mass Ratio ◽  
Drying Temperature ◽  
Leather Waste ◽  
The Cross

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.

scholarly journals Mineral plastic hydrogels from the cross-linking of polyacrylic acid and alkaline earth or transition metal ions

2019 ◽  
Vol 55 (34) ◽  
pp. 4913-4916 ◽  
Author(s):  
David J. Schupp ◽  
Xiaotong Zhang ◽  
Shengtong Sun ◽  
Helmut Cölfen
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Polyacrylic Acid ◽  
Alkaline Earth ◽  
Transition Metal Ions ◽  
Cross Linking ◽  
Inorganic Hybrid ◽  
Ph Values ◽  
Hybrid Hydrogels ◽  
The Cross

Based on ‘Mineral Plastics’, organic–inorganic hybrid hydrogels were synthesized by utilization of different metal ions and pH-values.

Cross-Linked Effects by Genipin on Physicochemical Properties of Chitosan Film

2016 ◽  
Vol 1133 ◽  
pp. 108-112
Author(s):  
Siti Farhana Hisham ◽  
Siti Hajar Kasim ◽  
Syazana Abu Bakar ◽  
Siti Noorzidah Mohd Sabri ◽  
Azreena Mastor ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Transmission Rate ◽  
Chitosan Film ◽  
Cross Linking ◽  
Elongation At Break ◽  
Oxygen Transmission Rate ◽  
Light Yellow ◽  
Vis Spectroscopy ◽  
The Cross ◽  
Dark Blue

The aim of this paper was to investigate the effects of cross-linked reaction on physicochemical properties of chitosan film by using genipin as cross-linker agent. Series of chitosan film samples with different amount concentration of genipin loaded (0-3 wt %) were prepared and characterized. The physicochemical properties of films were evaluated by Fourier Transform Infra-red (FTIR), UV-vis spectroscopy, Oxygen Transmission Rate (OTR), Scanning Electron Microscopy (SEM), water vapour and tensile test. The cross-linking reaction had affected on colour changing of chitosan film samples from light yellow to dark blue in line with the increasing of genipin concentration. Thus, UV-vis spectroscopy on the cross-linked samples showed the absorbance value at 600 nm wavelength due to genipin content. FTIR observation on cross-linked film samples showed no characteristic of –OCH3 peak from genipin at 1444 cm-1 which resulted by new covalent bonding occurred between chitosan and genipin. Cross-linking also had increased the oxygen barrier and reduced the water vapor rate through the film. Chitosan film sample with addition of 1 wt% genipin achieved the highest tensile stress average at 49.46 MPa compared to other samples while percent of elongation at break reduced with the increasing of genipin concentration loaded

scholarly journals Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

2021 ◽  
Author(s):  
Istebreq A. Saeedi ◽  
Sunny Chaudhary ◽  
Thomas Andritsch ◽  
Alun S. Vaughan
Keyword(s):  
Glass Transition ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Epoxy Resins ◽  
Functional Network ◽  
Cross Linking ◽  
Network Modifier ◽  
Epoxy Resin System ◽  
The Cross ◽  
The Impact

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.

scholarly journals The Effect of Surfactant-Modified Montmorillonite on the Cross-Linking Efficiency of Polysiloxanes

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik
Keyword(s):  
Total Pore Volume ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Cross ◽  
Chain Lengths ◽  
First Time ◽  
Substituent Influence ◽  
Benzyl Substituent

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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