Dissolution of natural polymers in ionic liquids: A review

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhuojun Meng ◽  
Xuejing Zheng ◽  
Keyong Tang ◽  
Jie Liu ◽  
Shufa Qin
Keyword(s):  
Ionic Liquids ◽  
High Strength ◽  
Polymer Materials ◽  
Structure And Properties ◽  
Natural Polymer ◽  
Natural Polymers ◽  
Keratin Fibers ◽  
Strength And Stiffness ◽  
Living Organisms ◽  
Chitin And Chitosan

AbstractNatural polymers are produced by living organisms, e.g. plants, animals, microorganisms. Natural polymer materials have gained increasing attention due to their high strength and stiffness combined with carbon neutral, biocompatibility, biodegradability, renewability and sustainability. However, due to the strong interand intra-molecular hydrogen bonds, many natural polymers are extremely difficult to be dissolved in water or traditional organic solvents. The processing difficulties tremendously limit the applications of natural polymers in many fields. Recently, using ionic liquids (ILs) as novel solvents to dissolve natural polymers has attracted increasing attention. ILs has been shown to be highly effective at dissolving some natural polymers to technically useful concentrations. In this article, the structure and basic properties of ILs are introduced; the recent progress is reviewed in the dissolution of several important natural polymers using ionic liquids, including cellulose, chitin and chitosan, wool keratin fibers, silk fibroin and collagen fibers. The dissolution mechanisms of natural polymers using ILs as solvents are analyzed. The structure and properties of native and regenerated natural polymers are discussed in details.

scholarly journals A Mini-Review on Chitosan Microsphere Drug Delivery

2021 ◽  
pp. 179-186
Author(s):  
Cinnayyagari Mahesh Reddy ◽  
S. Parimala Krishnan ◽  
Challa Balashekar Reddy
Keyword(s):  
Drug Delivery ◽  
Drug Carrier ◽  
Severe Disease ◽  
Natural Polymer ◽  
Natural Polymers ◽  
Drug Bioavailability ◽  
Duration Of Treatment ◽  
Polyelectrolyte Complexes ◽  
Drug Degradation ◽  
Chitin And Chitosan

The study aims to determine the drug therapy of any disease to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug carrier systems include polymers, micelles, microcapsules, Liposomes and lipoproteins etc. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually no biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyamines giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres or nanospheres and microcapsules. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. This review also aims to include the process variables factors that affect the release of drugs from the microspheres.

Influence of low-temperature tempering on structure and properties of welded joints of high-strength steel 30Kh2N2MF

2020 ◽  
Vol 2020 (6) ◽  
pp. 20-26
Author(s):  
O.A. Gaivoronskyi ◽  
◽  
V.D. Poznyakov ◽  
O.M. Berdnikova ◽  
T.O. Alekseenko ◽  
...  
Keyword(s):  
Low Temperature ◽  
Welded Joints ◽  
High Strength Steel ◽  
High Strength ◽  
Structure And Properties

scholarly journals Viscoelastic Polyurethane Foam with Keratin and Flame-Retardant Additives

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1380
Author(s):  
Krystyna Wrześniewska-Tosik ◽  
Joanna Ryszkowska ◽  
Tomasz Mik ◽  
Ewa Wesołowska ◽  
Tomasz Kowalewski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Resistance ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Release Rate ◽  
Structure And Properties ◽  
Burning Behavior ◽  
Keratin Fibers ◽  
Scanning Electron

Viscoelastic polyurethane (VEPUR) foams with increased thermal resistance are presented in this article. VEPUR foams were manufactured with the use of various types of flame retardant additives and keratin fibers. The structure of the modified foams was determined by spectrophotometric-(FTIR), thermal-(DSC), and thermogravimetric (TGA) analyses as well as by scanning electron microscopy (SEM). We also assessed the fire resistance, hardness, and comfort coefficient (SAG factor). It was found that the use of keratin filler and flame retardant additives changed the foams’ structure and properties as well as their burning behavior. The highest fire resistance was achieved for foams containing keratin and expanding graphite, for which the reduction in heat release rate (HRR) compared to VEPUR foams reached 75%.

scholarly journals The Synthesis of Poly(Vinyl Alcohol) Grafted with Fluorinated Protic Ionic Liquids Containing Sulfo Functional Groups

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4158
Author(s):  
Patrycja Glińska ◽  
Andrzej Wolan ◽  
Wojciech Kujawski ◽  
Edyta Rynkowska ◽  
Joanna Kujawa
Keyword(s):  
Ionic Liquids ◽  
Vinyl Alcohol ◽  
Proton Exchange ◽  
Polymer Materials ◽  
Polymerization Reaction ◽  
Poly Vinyl Alcohol ◽  
Hydroxyl Groups ◽  
Protic Ionic Liquids ◽  
Synthesis Route ◽  
Sulfo Groups

There has been an ongoing need to develop polymer materials with increased performance as proton exchange membranes (PEMs) for middle- and high-temperature fuel cells. Poly(vinyl alcohol) (PVA) is a highly hydrophilic and chemically stable polymer bearing hydroxyl groups, which can be further altered. Protic ionic liquids (proticILs) have been found to be an effective modifying polymer agent used as a proton carrier providing PEMs’ desirable proton conductivity at high temperatures and under anhydrous conditions. In this study, the novel synthesis route of PVA grafted with fluorinated protic ionic liquids bearing sulfo groups (–SO3H) was elaborated. The polymer functionalization with fluorinated proticILs was achieved by the following approaches: (i) the PVA acylation and subsequent reaction with fluorinated sultones and (ii) free-radical polymerization reaction of vinyl acetate derivatives modified with 1-methylimidazole and sultones. These modifications resulted in the PVA being chemically modified with ionic liquids of protic character. The successfully grafted PVA has been characterized using 1H, 19F, and 13C-NMR and FTIR-ATR. The presented synthesis route is a novel approach to PVA functionalization with imidazole-based fluorinated ionic liquids with sulfo groups.

scholarly journals Molecular-Level Investigation of Cycloaliphatic Epoxidised Ionic Liquids as a New Generation of Monomers for Versatile Poly(Ionic Liquids)

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1512
Author(s):  
Baris Demir ◽  
Gabriel Perli ◽  
Kit-ying Chan ◽  
Jannick Duchet-Rumeau ◽  
Sébastien Livi
Keyword(s):  
Ionic Liquids ◽  
Molecular Level ◽  
Computational Approach ◽  
Polymer Materials ◽  
Chemical Structures ◽  
Cycloaliphatic Epoxy ◽  
Polymer Models ◽  
Mechanical Performances ◽  
Dynamics Simulations ◽  
New Generation

Recently, a new generation of polymerised ionic liquids with high thermal stability and good mechanical performances has been designed through novel and versatile cycloaliphatic epoxy-functionalised ionic liquids (CEILs). From these first promising results and unexplored chemical structures in terms of final properties of the PILs, a computational approach based on molecular dynamics simulations has been developed to generate polymer models and predict the thermo–mechanical properties (e.g., glass transition temperature and Young’s modulus) of experimentally investigated CEILs for producing multi-functional polymer materials. Here, a completely reproducible and reliable computational protocol is provided to design, test and tune poly(ionic liquids) based on epoxidised ionic liquid monomers for future multi-functional thermoset polymers.

scholarly journals A Review on Coordination Properties of Al(III) and Fe(III) toward Natural Antioxidant Molecules: Experimental and Theoretical Insights

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2603
Author(s):  
Luana Malacaria ◽  
Giuseppina Anna Corrente ◽  
Amerigo Beneduci ◽  
Emilia Furia ◽  
Tiziana Marino ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Natural Antioxidants ◽  
Point Of View ◽  
Water Soluble ◽  
Natural Antioxidant ◽  
Theoretical Point ◽  
Structure And Properties ◽  
Coordination Properties ◽  
Soluble Molecule ◽  
Living Organisms

This review focuses on the ability of some natural antioxidant molecules (i.e., hydroxycinnamic acids, coumarin-3-carboxylic acid, quercetin, luteolin and curcumin) to form Al(III)- and Fe(III)-complexes with the aim of evaluating the coordination properties from a combined experimental and theoretical point of view. Despite the contributions of previous studies on the chemical properties and biological activity of these metal complexes involving such natural antioxidants, further detailed relationships between the structure and properties are still required. In this context, the investigation on the coordination properties of Al(III) and Fe(III) toward these natural antioxidant molecules might deserve high interest to design water soluble molecule-based metal carriers that can improve the metal’s intake and/or its removal in living organisms.

scholarly journals Materials for Automotive Lightweighting

2019 ◽  
Vol 49 (1) ◽  
pp. 327-359 ◽  
Author(s):  
Alan Taub ◽  
Emmanuel De Moor ◽  
Alan Luo ◽  
David K. Matlock ◽  
John G. Speer ◽  
...  
Keyword(s):  
Galvanic Corrosion ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
New Materials ◽  
Specific Strength ◽  
Advanced High Strength Steels ◽  
Strength And Stiffness ◽  
The Cost

Reducing the weight of automobiles is a major contributor to increased fuel economy. The baseline materials for vehicle construction, low-carbon steel and cast iron, are being replaced by materials with higher specific strength and stiffness: advanced high-strength steels, aluminum, magnesium, and polymer composites. The key challenge is to reduce the cost of manufacturing structures with these new materials. Maximizing the weight reduction requires optimized designs utilizing multimaterials in various forms. This use of mixed materials presents additional challenges in joining and preventing galvanic corrosion.

Ionic liquids as novel solvents for the dissolution and blending of wool keratin fibers

2005 ◽  
Vol 7 (8) ◽  
pp. 606 ◽  
Author(s):  
Haibo Xie ◽  
Shenghai Li ◽  
Suobo Zhang
Keyword(s):  
Ionic Liquids ◽  
Keratin Fibers ◽  
Wool Keratin

Synthesis and Characterization of Alkeyl Imidazolium Ionic Liquids

2014 ◽  
Vol 1048 ◽  
pp. 452-455
Author(s):  
Qiang Wang ◽  
Shi Dong Wang ◽  
Ming Chen Qi ◽  
Shu Liang Zang
Keyword(s):  
Ionic Liquids ◽  
Chemical Structure ◽  
Direct Synthesis ◽  
Synthesis Method ◽  
Structure And Properties ◽  
Spectra Analysis ◽  
Infrared Spectrometer ◽  
Liquid Salts ◽  
Structure Of Matter

Two new imidazole ionic liquid salts, 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-allyl-3-methy-imidazolium hydrogen sulfate ([EMIM]HSO4), were synthesized with direct synthesis and two-step synthesis method, using a viscosity meter, PH meter, conductivity meter, densitometer, infrared spectrometer determined its chemical structure and properties. The results show that two ionic liquids in the range is slightly different, the trend is roughly same. As the temperature increases, the viscosity decreases, PH gradually increased, the density decreases slightly, can be regarded as constant, the conductivity gradually increased. Ionic liquids of the two IR spectra analysis show its structure and synthetic route consistent with the structure of matter.

Sign in / Sign up

Export Citation Format

Share Document