scholarly journals Direct Fluorination as Method of Improvement of Operational Properties of Polymeric Materials

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2836
Author(s):  
Nikolay A. Belov ◽  
Alexander Y. Alentiev ◽  
Yulia G. Bogdanova ◽  
Artem Y. Vdovichenko ◽  
Dmitrii S. Pashkevich
Keyword(s):  
Chemical Structure ◽  
Chemical Resistance ◽  
Polymeric Materials ◽  
Barrier Properties ◽  
Elemental Fluorine ◽  
Energy Characteristics ◽  
Mechanical And Electrical Properties ◽  
Current Review ◽  
Direct Fluorination ◽  
Fluorinated Surface

Direct fluorination of polymers is a widely utilized technique for chemical modification. Such introduction of fluorine into the chemical structure of polymeric materials leads to laminates with highly fluorinated surface layer. The physicochemical properties of this layer are similar to those of perfluorinated polymers that differ by a unique combination of chemical resistance, weak adhesion, low cohesion, and permittivity, often barrier properties, etc. Surface modification by elemental fluorine allows one to avoid laborious synthesis of perfluoropolymers and impart such properties to industrial polymeric materials. The current review is devoted to a detailed consideration of wetting by water, energy characteristics of surfaces, adhesion, mechanical and electrical properties of the polymers, and composites after the direct fluorination.

scholarly journals Effect of Direct Fluorination on the Transport Properties and Swelling of Polymeric Materials: A Review

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 713
Author(s):  
Nikolay A. Belov ◽  
Dmitrii S. Pashkevich ◽  
Alexandre Yu Alentiev ◽  
Alain Tressaud
Keyword(s):  
Polymeric Materials ◽  
Polymeric Films ◽  
Methanol Permeability ◽  
Elemental Fluorine ◽  
Fuel Cell Membranes ◽  
Polymeric Blends ◽  
Direct Fluorination ◽  
Permeable Polymer ◽  
Surface Fluorination ◽  
Separation Parameters

Fluorine-containing polymers occupy a peculiar niche among conventional polymers due to the unique combination of physicochemical properties. Direct surface fluorination of the polymeric materials is one of the approaches for the introduction of fluorine into the chemical structure that allows one to implement advantages of fluorinated polymers in a thin layer. Current review considers the influence of the surface interaction of the polymeric materials and membranes with elemental fluorine on gas, vapor and liquid transport as well as swelling and related phenomena. The increase in direct fluorination duration and concentration of fluorine in the fluorination mixture is shown to result mostly in a reduction of all penetrants permeability to a different extent, whereas selectivity of the selected gas pairs (He-H2, H2-CH4, He-CH4, CO2-CH4, O2-N2, etc.) increases. Separation parameters for the treated polymeric films approach Robeson’s upper bounds or overcome them. The most promising results were obtained for highly permeable polymer, polytrimethylsilylpropyne (PTMSP). The surface fluorination of rubbers in printing equipment leads to an improved chemical resistance of the materials towards organic solvents, moisturizing solutions and reduce diffusion of plasticizers, photosensitizers and other components of the polymeric blends. The direct fluorination technique can be also considered one of the approaches of fabrication of fuel cell membranes from non-fluorinated polymeric precursors that improves their methanol permeability, proton conductivity and oxidative stability.

The Barrier Properties of Carbon-Chain and Heterochain Polymers and Polymer Composite Materials

2018 ◽  
Vol 45 (2) ◽  
pp. 67-70
Author(s):  
A.I. Ermilova ◽  
O.B. Ushakova ◽  
E.V. Kalugina
Keyword(s):  
Chemical Structure ◽  
Polymeric Materials ◽  
Barrier Properties ◽  
Polyamide 6 ◽  
Carbon Chain ◽  
Hot Water ◽  
Gas Barrier ◽  
Water Pipes ◽  
Heterochain Polymers ◽  
Organomodified Montmorillonite

A comparative assessment of the gas barrier properties of polymeric materials of different chemical structure and of composites with organomodified montmorillonite based on polyamide-6 is carried out, with the aim of using them as a barrier layer for polymer hot water pipes.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

scholarly journals Electrochemically Produced Copolymers of Pyrrole and Its Derivatives: A Plentitude of Material Properties Using “Simple” Heterocyclic Co-Monomers

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 281
Author(s):  
Tomasz Jarosz ◽  
Przemyslaw Ledwon
Keyword(s):  
Biological Activity ◽  
Material Properties ◽  
Building Block ◽  
Conjugated Polymer ◽  
Chemical Structure ◽  
Heterocyclic System ◽  
Repeat Unit ◽  
Polymeric Materials ◽  
Pyrrole Derivatives ◽  
Pyrrole Monomer

Polypyrrole is a classical, well-known conjugated polymer that is produced from a simple heterocyclic system. Numerous pyrrole derivatives exhibit biological activity, and the repeat unit is a common building block present in the chemical structure of many polymeric materials, finding wide application, primarily in optoelectronics and sensing. In this work, we focus on the variety of copolymers and their material properties that can be produced electrochemically, even though all these systems are obtained from mixtures of the “simple” pyrrole monomer and its derivatives with different conjugated and non-conjugated species.

scholarly journals Nanocomposites Materials of PLA Reinforced with Nanoclays Using a Masterbatch Technology: A Study of the Mechanical Performance and Its Sustainability

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2133
Author(s):  
Helena Oliver-Ortega ◽  
Josep Tresserras ◽  
Fernando Julian ◽  
Manel Alcalà ◽  
Alba Bala ◽  
...  
Keyword(s):  
Food Packaging ◽  
Mechanical Performance ◽  
Polymeric Materials ◽  
Barrier Properties ◽  
Food Tray ◽  
Environmental Concerns ◽  
Poly Lactic Acid ◽  
The Matrix ◽  
Surface Modified ◽  
Being Moved

Packaging consumes around 40% of the total plastic production. One of the most important fields with high requirements is food packaging. Food packaging products have been commonly produced with petrol polymers, but due to environmental concerns, the market is being moved to biopolymers. Poly (lactic acid) (PLA) is the most promising biopolymer, as it is bio-based and biodegradable, and it is well established in the market. Nonetheless, its barrier properties need to be enhanced to be competitive with other polymers such as polyethylene terephthalate (PET). Nanoclays improve the barrier properties of polymeric materials if correct dispersion and exfoliation are obtained. Thus, it marks a milestone to obtain an appropriate dispersion. A predispersed methodology is proposed as a compounding process to improve the dispersion of these composites instead of common melt procedures. Afterwards, the effect of the polarity of the matrix was analyzing using polar and surface modified nanoclays with contents ranging from 2 to 8% w/w. The results showed the suitability of the predispersed and concentrated compound, technically named masterbatch, to obtain intercalated structures and the higher dispersion of polar nanoclays. Finally, the mechanical performance and sustainability of the prepared materials were simulated in a food tray, showing the best assessment of these materials and their lower fingerprint.

The formation of halogenated succinates by liquid-phase direct fluorination with elemental fluorine

1994 ◽  
Vol 67 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Robert G. Syvret ◽  
Daniel L. Vassilaros ◽  
David M. Parees ◽  
Guido P. Pez
Keyword(s):  
Liquid Phase ◽  
Elemental Fluorine ◽  
Direct Fluorination

An Investigation of the Barrier Properties and of the Residual Acetaldehyde in Polyethylene Terephthalate Composites

2017 ◽  
Vol 44 (12) ◽  
pp. 19-22
Author(s):  
A.S. Shabaev ◽  
S.Yu. Khashirova ◽  
A.K. Mikitaev ◽  
I.V. Musov ◽  
A.L. Slonov
Keyword(s):  
Carbon Dioxide ◽  
Polymer Composites ◽  
Polyethylene Terephthalate ◽  
Oxygen Permeability ◽  
Gas Permeability ◽  
Polymeric Materials ◽  
Barrier Properties ◽  
Diffusion Cell ◽  
Polybutylene Terephthalate

The diffusion cell to a Tsvet-800 chromatograph for determining the gas permeability of polymeric materials has been optimised. The oxygen permeability and the carbon dioxide permeability of polymer composites based on polyethylene terephthalate and polybutylene terephthalate have been studied. The optimum compositions, combining high barrier properties and a low acetaldehyde content, have been found.

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