scholarly journals Cross-Linking Strategies for Fluorine-Containing Polymer Coatings for Durable Resistant Water- and Oil-Repellency

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 723
Author(s):  
Julia Kredel ◽  
Deborah Schmitt ◽  
Jan-Lukas Schäfer ◽  
Markus Biesalski ◽  
Markus Gallei
Keyword(s):  
Textile Industry ◽  
Uv Light ◽  
Tensile Elongation ◽  
Water Repellency ◽  
Ethyl Acrylate ◽  
Polymer Coatings ◽  
Cross Linking ◽  
Functional Coatings ◽  
Functional Coating ◽  
The Cross

Functional coatings for application on surfaces are of growing interest. Especially in the textile industry, durable water and oil repellent finishes are of special demand for implementation in the outdoor sector, but also as safety-protection clothes against oil or chemicals. Such oil and chemical repellent textiles can be achieved by coating surfaces with fluoropolymers. As many concerns exist regarding (per)fluorinated polymers due to their high persistence and accumulation capacity in the environment, a durable and resistant coating is essential also during the washing processes of textiles. Within the present study, different strategies are examined for a durable resistant cross-linking of a novel fluoropolymer on the surface of fibers. The monomer 2-((1,1,2-trifluoro-2-(perfluoropropoxy)ethyl)thio)ethyl acrylate, whose fluorinated side-chain is degradable by treatment with ozone, was used for this purpose. The polymers were synthesized via free radical polymerization in emulsion, and different amounts of cross-linking reagents were copolymerized. The final polymer dispersions were applied to cellulose fibers and the cross-linking was induced thermally or by irradiation with UV-light. In order to investigate the cross-linking efficiency, tensile elongation studies were carried out. In addition, multiple washing processes of the fibers were performed and the polymer loss during washing, as well as the effects on oil and water repellency were investigated. The cross-linking strategy paves the way to a durable fluoropolymer-based functional coating and the polymers are expected to provide a promising and sustainable alternative to functional coatings.

A photoenhanced oxidation of amino acids and the cross-linking of lysozyme mediated by tetrazolium salts

2021 ◽  
Vol 23 (6) ◽  
pp. 3761-3770
Author(s):  
Jianfeng Zhao ◽  
Ruixue Zhu ◽  
Xiting Zhang ◽  
Bowu Zhang ◽  
Yancheng Liu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Uv Light ◽  
Cross Linking ◽  
Tetrazolium Salts ◽  
The Cross

Mechanisms of UV light-enabled strong oxidizing capacity of tetrazolium salts and their oxidization towards proteins were first elucidated.

scholarly journals Photochemical cross-linking of cap binding proteins to eucaryotic mRNAs: effect of mRNA 5' secondary structure.

1985 ◽  
Vol 5 (11) ◽  
pp. 3222-3230 ◽  
Author(s):  
J Pelletier ◽  
N Sonenberg
Keyword(s):  
Secondary Structure ◽  
Binding Proteins ◽  
Uv Light ◽  
Specific Interaction ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Cross Linking ◽  
Kinase Gene ◽  
The Cross

We used UV light-induced cross-linking to study the interactions of cap binding proteins with the 5' cap structure of eucaryotic mRNAs. Thymidine kinase gene (herpes simplex virus type 1) transcripts prepared in vitro using the SP6 RNA polymerase transcription system were capped and methylated posttranscriptionally with [alpha-32P]GTP and S-adenosyl-L-methionine to yield cap-labeled transcripts. Irradiation of capped transcripts with crude rabbit reticulocyte initiation factors in the presence of ATP-Mg2+ resulted in the cap-specific cross-linking of two polypeptides with molecular masses of 24 and 80 kilodaltons (kDa). The cross-linking characteristics of these polypeptides resemble those of the cap-binding proteins previously detected by a chemical cross-linking assay (N. Sonenberg, D. Guertin, D. Cleveland, and H. Trachsel, Cell 27:563-572, 1981). However, the relative efficiency of the cross-linking of these two polypeptides to the cap structure was different from that in previous studies, and there was no detectable cross-linking of the previously described 50-kDa polypeptide. In addition, we present data indicating that the insertion of secondary structure into the 5' noncoding region of tk mRNA, 6 nucleotides from the cap structure, decreases the cap-specific cross-linking of the 80-kDa but not the 24-kDa polypeptide. In contrast, the insertion of secondary structure 37 nucleotides from the cap structure had no significant effect on the cross-linking of either the 24- or the 80-kDa cap-specific polypeptide. These results demonstrate that the position of mRNA 5'-proximal secondary structure relative to the cap structure can influence the cap-specific interaction between the mRNA and a translation initiation factor.

Photochemical cross-linking of cap binding proteins to eucaryotic mRNAs: effect of mRNA 5' secondary structure

1985 ◽  
Vol 5 (11) ◽  
pp. 3222-3230
Author(s):  
J Pelletier ◽  
N Sonenberg
Keyword(s):  
Secondary Structure ◽  
Binding Proteins ◽  
Uv Light ◽  
Specific Interaction ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Cross Linking ◽  
Kinase Gene ◽  
The Cross

We used UV light-induced cross-linking to study the interactions of cap binding proteins with the 5' cap structure of eucaryotic mRNAs. Thymidine kinase gene (herpes simplex virus type 1) transcripts prepared in vitro using the SP6 RNA polymerase transcription system were capped and methylated posttranscriptionally with [alpha-32P]GTP and S-adenosyl-L-methionine to yield cap-labeled transcripts. Irradiation of capped transcripts with crude rabbit reticulocyte initiation factors in the presence of ATP-Mg2+ resulted in the cap-specific cross-linking of two polypeptides with molecular masses of 24 and 80 kilodaltons (kDa). The cross-linking characteristics of these polypeptides resemble those of the cap-binding proteins previously detected by a chemical cross-linking assay (N. Sonenberg, D. Guertin, D. Cleveland, and H. Trachsel, Cell 27:563-572, 1981). However, the relative efficiency of the cross-linking of these two polypeptides to the cap structure was different from that in previous studies, and there was no detectable cross-linking of the previously described 50-kDa polypeptide. In addition, we present data indicating that the insertion of secondary structure into the 5' noncoding region of tk mRNA, 6 nucleotides from the cap structure, decreases the cap-specific cross-linking of the 80-kDa but not the 24-kDa polypeptide. In contrast, the insertion of secondary structure 37 nucleotides from the cap structure had no significant effect on the cross-linking of either the 24- or the 80-kDa cap-specific polypeptide. These results demonstrate that the position of mRNA 5'-proximal secondary structure relative to the cap structure can influence the cap-specific interaction between the mRNA and a translation initiation factor.

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.

Effects of a crosslinking agent on a supramolecular gel to control lost circulation

2021 ◽  
Vol 45 (16) ◽  
pp. 7089-7095
Author(s):  
Bo Wang ◽  
Jinsheng Sun ◽  
Kaihe Lv ◽  
Feng Shen ◽  
Yingrui Bai
Keyword(s):  
Crosslinking Agent ◽  
Network Density ◽  
Cross Linking ◽  
Supramolecular Gel ◽  
Lost Circulation ◽  
The Cross

The Cr3+ can improve the cross-linking degree and network density of the GP-A gel, and enhance its strength and plugging ability to control lost circulation.

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