Blends Containing Amphiphilic Biopolymers. Compatibility Behavior

2021 ◽  
Vol 18 ◽  
Author(s):  
Cristian Castro ◽  
Ligia Gargallo ◽  
Deodato Radić
Keyword(s):  
Single Phase ◽  
Polymeric Materials ◽  
Functionalized Polymers ◽  
Heat Of Mixing ◽  
Natural Polymers ◽  
Vinyl Polymers ◽  
Polymeric Blends ◽  
Marine Crustaceans ◽  
Direct Separation ◽  
Multifunctional Polymers

: This mini-review deals with the miscibility behavior of two biopolymers, chitosan, and alginate. It is well known that the miscibility in multifunctional polymers blends is favored due to specific interactions, which origin a negative heat of mixing. Particular interest is focused on functionalized polymers because they are the most suitable way to obtain interacting polymers, producing a single-phase material. Due to the polyfunctionality of chitosan (CS) and other biopolymers, they can be taken into account as a basis of a strongly interacting polymer. They would allow obtaining compatible polymeric materials. For this reason, blends containing CS with different vinyl polymers have been studied. The most significant polymeric blends with these natural polymers will be analyzed in this review. Chitosan is obtained from the biopolymer chitin through sequential processes of demineralization, deproteinization, and deacetylation. The native chitin is obtained by direct separation from the marine crustaceans shell, abundant on the sea coasts. Some classic results that relate to the polymeric blends containing amphiphilic polymers will be discussed. Another biopolymer of the coast is Sodium Alginate (SA). Alginate also allows the formation of compatible polymer blends. Results in this regard will also be analyzed in this review.

New Carbohydrate-Based Polymeric Materials

MRS Bulletin ◽  
1992 ◽  
Vol 17 (10) ◽  
pp. 54-59 ◽  
Author(s):  
Matthew R. Callstrom ◽  
Mark D. Bednarski
Keyword(s):  
Food Additives ◽  
Polymeric Materials ◽  
Water Soluble ◽  
Natural Polymers ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Chemically Modified ◽  
Stereochemical Control ◽  
Natural Polysaccharide ◽  
Image Position

The total world production of water-soluble polymers is estimated to be greater than five million tons per year. Water-soluble polymers are most conveniently described according to their origin in three classes (see Structures 1-6):∎ Natural polymers, including starch (1) and cellulose (2);∎ chemically modified natural polymers, including, for example, hydroxyethyl starch (3) and cellulose acetate (4); and∎ synthetic polymers, the most important of which are polyacrylamide (5) and polyvinyl alcohol (6), (commonly composed of both alcohol and acetate groups as shown). The widespread use of these materials is due to both their availability and the range of useful physical properties found in the various natural and chemically modified natural polymers.Of the commercial water-soluble polymers, approximately 50–80% are based on natural polysaccharide materials. One of the primary reasons that these materials find such widespread use is the dramatic response of their properties to changes in their functionality and stereochemistry: chemical modification or the combination of polysaccharides with other polymeric materials has yielded materials whose applications range from explosives to food additives. Although efforts directed at controlling the properties of polysaccharides has resulted in a wide variety of useful materials, we felt control of the composition of carbohydrate-based polymers at the molecular level would provide materials with properties superior to those derived from natural and chemically modified polysaccharide materials.Our approach for the preparation of new carbohydrate-based materials is to use the carbohydrate as a template for the introduction of desired functionality with complete regiochemical and stereochemical control by both chemical and enzymatic methods (Scheme I).

End-Functionalized Polymers by Controlled/Living Radical Polymerizations: Synthesis and Applications

2021 ◽  
Author(s):  
Di Zhou ◽  
Liang-Wei Zhu ◽  
Bai-Heng Wu ◽  
Zhi-Kang Xu ◽  
Ling-Shu Wan
Keyword(s):  
Polymeric Materials ◽  
Functionalized Polymers ◽  
The Past ◽  
Living Radical Polymerizations ◽  
Radical Polymerizations

The precise design of polymers with well-defined end functionality has received great interest for synthesizing polymeric materials with advanced or distinctive properties. In the past decades, considerable attention has been...

ALLOY PHASE FORMATION BY MECHANICAL ALLOYING: CONSTRAINTS AND MECHANISMS

1992 ◽  
Vol 06 (03) ◽  
pp. 127-138 ◽  
Author(s):  
E. MA ◽  
M. ATZMON
Keyword(s):  
Mechanical Alloying ◽  
Phase Formation ◽  
Single Phase ◽  
Metastable Phase ◽  
Interfacial Free Energy ◽  
Metastable Equilibrium ◽  
Heat Of Mixing ◽  
Layered Composites ◽  
Two Phase ◽  
Equilibrium Phases

Alloy phase formation in binary metallic systems by mechanical alloying (MA) of elemental powders is briefly reviewed. Our recent results indicate the inadequacy of the current understanding of the MA process, which has been depicted as an isothermal solid-state interdiffusion reaction under interfacial, metastable, equilibrium in layered composites. A structural and thermodynamic analysis of the supersaturation followed by amorphization in the Zr-Al system demonstrates that a system can be constrained to be a single phase without reaching two-phase (metastable) equilibrium during MA. Alloying, resulting in a single metastable phase, has also been achieved in immiscible systems with positive heat of mixing, such as Fe-Cu. In both cases, the interfacial free energy associated with a repeatedly deformed, fine-structured, two-phase alloy appears to pose polymorphous constraints. In addition, equilibrium phases can be formed during MA in an exothermic, self-sustained fashion, as observed for the formation of AlNi. Al-Ni phases formed under different milling conditions suggest that self-sustained reactions may occur, undetected, on a grain-by-grain basis.

Characterization of Electron Beam Irradiated Polyvinylpyrrolidone-Dextran (PVP/DEX) Blends

2012 ◽  
Vol 188 ◽  
pp. 102-108 ◽  
Author(s):  
Maria Dumitraşcu ◽  
Mădălina Georgiana Albu ◽  
Marian Vîrgolici ◽  
Cătălin Vancea ◽  
Viorica Meltzer
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Polymeric Materials ◽  
Beam Irradiation ◽  
Molecular Weights ◽  
The Past ◽  
Polymeric Blends ◽  
Irradiation Treatment ◽  
Ft Ir

In the past years an increased interest to create new polymeric blends with application in the medical area for development of new types of biomaterials has appeared. Electron beam irradiation is well known as a method of producing important changes in polymer structure, being an alternative to chemical synthesis of biomaterials based on polymeric materials. The aim of the present study was to investigate the behaviour of some polyvinylpyrrolidone-dextran (PVP/DEX) blends under electron beam irradiation. Aqueous solutions of PVP with molecular weights of 360 000 Da (PVP 360), 40 000 Da (PVP 40), and DEX with molecular weight of 500 000 Da (DEX), were mixed as to obtain 50:50 blends of PVP40/DEX and PVP360/DEX. The obtained blends were irradiated with electron beam at different radiation doses and after irradiation treatment were processed by freeze-drying. PVP/DEX blends were characterized by infrared spectroscopy (FT-IR) and thermal analysis. The analyses were conducted in order to establish the relation between radiation dose and changes of structural and thermal properties.

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.

An In-Vitro Investigation of Sliding Friction Between Biomaterials for Cartilage Substitution and Articular Cartilage

2005 ◽  
Author(s):  
E. Northwood ◽  
R. Kowalski ◽  
J. Fisher
Keyword(s):  
Articular Cartilage ◽  
Single Phase ◽  
Sliding Friction ◽  
Frictional Coefficient ◽  
Polymeric Materials ◽  
Fluid Phase ◽  
Load Carriage ◽  
Simple Geometry ◽  
In Vitro Investigation

Understanding friction and wear of biomaterials when in contact with articular cartilage is vital within the development of future hemi-arthroplasty and cartilage substitution. This study aimed to compare the frictional properties of single phase and biphasic polymeric materials against articular cartilage. Continuous sliding friction was applied by means of a simple geometry wear simulator. The single-phase polymers produced peak frictional values of 0.37(±0.02). The biphasic hydrogel produced a peak frictional coefficient of 0.17(±0.05). It is postulated that this reduction in friction can be attributed to its biphasic properties, which instigates the fluid phase load carriage within the articular cartilage/hydrogel interface to be maintained for longer, reducing the frictional coefficient. This study illustrates the importance of biphasic properties within the tribology of future cartilage substitution materials.

scholarly journals Bio- and Fossil-Based Polymeric Blends and Nanocomposites for Packaging: Structure–Property Relationship

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 471 ◽  
Author(s):  
Francesca Luzi ◽  
Luigi Torre ◽  
José Kenny ◽  
Debora Puglia
Keyword(s):  
Polymeric Materials ◽  
Barrier Properties ◽  
Synthetic Polymers ◽  
Structure Property ◽  
Functional Behavior ◽  
Polymeric Blends ◽  
Light Barrier ◽  
Nanocomposite System ◽  
Structure Property Relationship ◽  
Packaging Structure

In the present review, the possibilities for blending of commodities and bio-based and/or biodegradable polymers for packaging purposes has been considered, limiting the analysis to this class of materials without considering blends where both components have a bio-based composition or origin. The production of blends with synthetic polymeric materials is among the strategies to modulate the main characteristics of biodegradable polymeric materials, altering disintegrability rates and decreasing the final cost of different products. Special emphasis has been given to blends functional behavior in the frame of packaging application (compostability, gas/water/light barrier properties, migration, antioxidant performance). In addition, to better analyze the presence of nanosized ingredients on the overall behavior of a nanocomposite system composed of synthetic polymers, combined with biodegradable and/or bio-based plastics, the nature and effect of the inclusion of bio-based nanofillers has been investigated.

Sequence-defined non-natural polymers: synthesis and applications

2019 ◽  
Vol 10 (40) ◽  
pp. 5406-5424 ◽  
Author(s):  
Pandurangan Nanjan ◽  
Mintu Porel
Keyword(s):  
Functional Diversity ◽  
Biomedical Applications ◽  
Polymeric Materials ◽  
Next Generation ◽  
Natural Polymers

Sequence-defined polymer: A promising gateway for the next generation polymeric materials and vast opportunities for new synthetic strategies, functional diversity and its material and biomedical applications.

scholarly journals Microbial production of megadalton titin yields fibers with advantageous mechanical properties

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher H. Bowen ◽  
Cameron J. Sargent ◽  
Ao Wang ◽  
Yaguang Zhu ◽  
Xinyuan Chang ◽  
...  
Keyword(s):  
Small Molecules ◽  
High Performance ◽  
Polymeric Materials ◽  
High Strength ◽  
Microbial Production ◽  
Damping Capacity ◽  
Natural Polymers ◽  
Potential Applications ◽  
Chain Slippage ◽  
Synthetic And Natural Polymers

AbstractManmade high-performance polymers are typically non-biodegradable and derived from petroleum feedstock through energy intensive processes involving toxic solvents and byproducts. While engineered microbes have been used for renewable production of many small molecules, direct microbial synthesis of high-performance polymeric materials remains a major challenge. Here we engineer microbial production of megadalton muscle titin polymers yielding high-performance fibers that not only recapture highly desirable properties of natural titin (i.e., high damping capacity and mechanical recovery) but also exhibit high strength, toughness, and damping energy — outperforming many synthetic and natural polymers. Structural analyses and molecular modeling suggest these properties derive from unique inter-chain crystallization of folded immunoglobulin-like domains that resists inter-chain slippage while permitting intra-chain unfolding. These fibers have potential applications in areas from biomedicine to textiles, and the developed approach, coupled with the structure-function insights, promises to accelerate further innovation in microbial production of high-performance materials.

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