scholarly journals Synthesis of random copolymer of isobutylene with p-methylstyrene by cationic polymerization in ionic liquids

e-Polymers ◽  
2018 ◽  
Vol 18 (5) ◽  
pp. 423-431 ◽  
Author(s):  
Xiaoqian Zhang ◽  
Wenli Guo ◽  
Yibo Wu ◽  
Yuwei Shang ◽  
Shuxin Li ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Random Copolymer ◽  
Monomer Conversion ◽  
High Viscosity ◽  
Feed Ratio ◽  
Copolymer Composition ◽  
Ionization Time ◽  
Cationic Copolymerization ◽  
Monomer Feed ◽  
New Generation

AbstractPoly(isobutylene-co-p-methylstyrene) (IB/p-MeSt) random copolymer is a new generation of polyisobutylene-based elastomer. The cationic copolymerization of IB with p-MeSt was thoroughly examined by using various initiating systems in [Hmim][NTf2] at −30°C. The effects of initiating systems and monomer feed ratio on the monomer conversion, molecular weight and copolymer composition are discussed. The polymers were characterized by 1H-nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and matrix-assisted laser desorption/ionization-time-of-flight-mass spectroscopy (MALDI-TOF-MS) to determine their chemical composition and molecular structure. The results show that high polarity, high viscosity and ionic environment of ionic liquids (ILs) influenced the copolymerization. The corresponding mechanism of cationic copolymerization in ILs is also proposed.

Influence of Ionic Liquids on the Free Radical Copolymerization of Styrene with Acrylonitrile

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Inga Woecht ◽  
Gudrun Schmidt-Naake
Keyword(s):  
Ionic Liquids ◽  
Free Radical ◽  
Radical Copolymerization ◽  
Polymerization Rate ◽  
Dimethyl Formamide ◽  
Copolymer Composition ◽  
Free Radical Copolymerization ◽  
Molecular Weights ◽  
Monomer Feed ◽  
Dibenzoyl Peroxide

AbstractFree radical copolymerization of styrene (S) and acrylonitrile (AN) in the ionic liquids (ILs) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), 1,3-dimethylimidazolium dimethylphosphate ([MMIM]Me2PO4) and 1-ethyl-3- methylimidazolium ethylsulfate ([EMIM]EtSO4) were investigated. 2,2’-azobisiso butyronitrile (AIBN) and dibenzoyl peroxide (BPO) were used as initiators and dimethyl formamide (DMF) and methanol as reference solvents. The influence of the viscosity on the conversion and the molecular weights was studied by variation of the reaction temperature and the IL concentration. At reaction temperatures of 80 - 85 °C already after 30 minutes a conversion of about 80 % and almost a doubling of the molecular weights is reached for the S/AN (50/50 mol%) copolymerization. In addition the copolymerization behavior of S/AN in [EMIM]EtSO4 was investigated. With increasing concentration of AN in the monomer feed the polymerization rate as well as the molecular weights of the copolymers increase. The influence of the ionic liquid on the copolymer composition, glass-transition temperature and rheological behavior was studied.

Polymerized Ionic Liquids: The Effect of Random Copolymer Composition on Ion Conduction

2009 ◽  
Vol 42 (13) ◽  
pp. 4809-4816 ◽  
Author(s):  
Hong Chen ◽  
Jae-Hong Choi ◽  
David Salas-de la Cruz ◽  
Karen I. Winey ◽  
Yossef A. Elabd
Keyword(s):  
Ionic Liquids ◽  
Random Copolymer ◽  
Copolymer Composition ◽  
Ion Conduction

Biocompatibility of Dicationic Imidazolium-Based Ionic Liquids: A New Generation of Multifunctional Coatings for Titanium Implants

2019 ◽  
Author(s):  
Sutton E. Wheelis ◽  
Claudia C. Biguetti ◽  
Shruti Natarajan ◽  
Lidia Guida ◽  
Brian Hedden ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Titanium Implants ◽  
New Generation

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 Cationic Copolymerization of Isobutylene with 4-Vinylbenzenecyclobutylene: Characteristics and Mechanisms

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 201 ◽  
Author(s):  
Zhifei Chen ◽  
Shuxin Li ◽  
Yuwei Shang ◽  
Shan Huang ◽  
Kangda Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cationic Polymerization ◽  
Transfer Reaction ◽  
Chain Transfer ◽  
Solid Phase ◽  
Random Copolymer ◽  
Glass Transition Temperatures ◽  
Cationic Copolymerization ◽  
Chain Transfer Reaction

A random copolymer of isobutylene (IB) and 4-vinylbenzenecyclobutylene (4-VBCB) was synthesized by cationic polymerization at −80 °C using 2-chloro-2,4,4-trimethylpentane (TMPCl) as initiator. The laws of copolymerization were investigated by changing the feed quantities of 4-VBCB. The molecular weight of the copolymer decreased, and its molecular weight distribution (MWD) increased with increasing 4-VBCB content. We proposed a possible copolymerization mechanism behind the increase in the chain transfer reaction to 4-VBCB with increasing of feed quantities of 4-VBCB. The thermal properties of the copolymers were studied by solid-phase heating and crosslinking. After crosslinking, the decomposition and glass transition temperatures (Tg) of the copolymer increased, the network structure that formed did not break when reheated, and the mechanical properties remarkably improved.

Experimental and numerical investigation of electrostatic spray liquid-liquid extraction with ionic liquids

2012 ◽  
Vol 33 (1) ◽  
pp. 167-183 ◽  
Author(s):  
Marek Krawczyk ◽  
Kamil Kamiński ◽  
Jerzy Petera
Keyword(s):  
Ionic Liquids ◽  
Numerical Investigation ◽  
High Viscosity ◽  
Liquid Extraction ◽  
Separation Processes ◽  
Organic Mixture ◽  
Liquid Liquid Extraction ◽  
Key Factor ◽  
A New Technique ◽  
Electrostatic Spray

Experimental and numerical investigation of electrostatic spray liquid-liquid extraction with ionic liquids A new concept of an electrostatic spray column for liquid-liquid extraction was investigated. An important problem for separation processes is the presence of azeotropic or close-boiling mixtures in their production, for example heptane with ethanol, since the separation is impossible by ordinary distillation. The use of ionic liquids (IL) as a dispersed solvent specially engineered for any specific organic mixture in terms of selectivity is a key factor to successful separation. As IL present particularly attractive combination of favorable characteristics for the separation of heptane and ethanol, in this work we use 1-butyl-3-methylimidazolium methyl sulfate [BMIM][MeSO4]. Because of high viscosity and relatively high cost of IL a new technique was introduced, consisting in the electrostatically spray generation to enhance the mass transport between the phases. In order to optimally design the geometry of the contactor a series of numerical simulation was performed. Especially multi-nozzle variants for better exploitation of contactor volume were investigated. Experiments showed excellent possibility of control of the dispersion characteristics by applied voltage and thus control of the rate of extraction. The preliminary simulations based on our mathematical model for a three nozzle variant exhibited visual agreement with the theory of electrostatics.

Synthesis, characterisation and properties of aramid copolymers prepared from AB and AB2 monomers

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Orietta Monticelli ◽  
Stefano Fiori ◽  
Alberto Mariani ◽  
Saverio Russo ◽  
Hartmut Komber
Keyword(s):  
Liquid Crystalline ◽  
Reaction Medium ◽  
Aromatic Polyamide ◽  
Degree Of Crystallinity ◽  
Feed Ratio ◽  
Structure Evolution ◽  
Monomer Composition ◽  
Degradation Temperature ◽  
Monomer Feed ◽  
Monomer Feed Ratio

Abstract Aromatic polyamide (aramid) copolymers having a highly branched architecture were prepared by direct polycondensation of an AB2 monomer (5-(4-aminobenzoylamino) isophthalic acid) with an AB monomer (N-(4-aminophenyl)terephthalamic acid). Two synthetic routes have been followed for copolymer preparation, differing from each other in the overall monomer content and the type of salts added to the reaction medium (LiCl or LiCl + CaCl2). Otherwise, both methods used the same conditions and the same condensing agent (triphenyl phosphite). The feed ratio of the monomers affected the copolymer solubility in aprotic polar solvents such as N,N-dimethylformamide, N-methylpyrrolidone and dimethyl sulfoxide. Only high AB2/AB monomer ratios allowed obtaining completely soluble polymers in the above media. Also copolymer intrinsic viscosity was influenced by that ratio as well as by the polymerisation routes. IR measurements gave an indication of polymer structure evolution as a function of the monomer feed ratio, while 1H NMR experiments verified the actual monomer composition in the synthesized polymers. The monomer feed ratio turned out to influence polymer properties, such as degree of crystallinity, thermal degradation temperature and liquid crystalline behaviour. Some of the characterisation techniques we used (1H and 31P NMR, IR, SEM-EDS) revealed the presence of phosphorus derivatives in the copolymers, despite extensive sample purification. This presence is coming from derivatives of the condensing agent, and is directly related to the content of AB2-type structures present in the copolymers.

scholarly journals Modification of Chitin Particles with Ionic Liquids Containing Ethyl Substituent in a Cation

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Malgorzata M. Jaworska ◽  
Andrzej Górak ◽  
Joanna Zdunek
Keyword(s):  
Particle Size ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Hydrogen Bonds ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
High Viscosity ◽  
Physical Structure ◽  
Ethyl Group ◽  
Network Of Hydrogen Bonds

Chitin cannot be dissolved in conventional solvents due to the strong inter- and intrasheet network of hydrogen bonds and the large number of crystalline regions. Some ionic liquids (ILs) have been suggested in the literature as possible solvents for chitin. Seven of them, all having an ethyl group as substituent in the cationic ring, have been tested in this work: [Emim][Cl], [Emim][Br], [Emim][I], [Emim][OAc], [Emim][Lact], [Epyr][I], and [EMS][BFSI]. Chitin was insoluble in [EMS][BFSI] while for all other ILs solubility was limited due to high viscosity of solutions and equilibria have not been reached. Changes in physical structure, particle size distribution, and crystallinity of recovered chitin depended on ionic liquid used. Increase in porosity was observed for chitin treated with [Emim][Cl], [Emim][I], [Emim][Br], and [Emim][Lact]; changes in particle size distribution were observed for [Emim][AcOH] and [EMS][BFSI]; increase in crystallinity was noticed for chitin treated with [Epyr][I] while decrease in crystallinity for [Emim][I] was noticed. All tested ionic liquids were reused four times and changes in FTIR spectra could be observed for each IL.

scholarly journals A Review of the electrochemical corrosion of metals in choline chloride based deep eutectic solvents

2021 ◽  
Author(s):  
Mihael Bučko ◽  
Jelena Bajat
Keyword(s):  
Ionic Liquids ◽  
Corrosion Rate ◽  
Wide Spectrum ◽  
Choline Chloride ◽  
Electrochemical Corrosion ◽  
Deep Eutectic Solvents ◽  
High Viscosity ◽  
Metal Corrosion ◽  
Melting Points ◽  
Separate Class

Deep eutectic solvents (DESs) are a class of mixtures with melting points notably lower than those of their raw constituent components. These liquids have found a tremendously wide spectrum of applications in the last two decades of their research, so their contact and interaction with technical metals and alloys are inevitable. Therefore, the corrosivity of DESs towards metals is an extremely important topic. This review summarizes research efforts collected in the last two decades related to the corrosion rate of various metals in different DESs. Since the DESs are mainly composed of organic raw compounds, and by their physicochemical properties they may be regarded as a separate class of ionic liquids, the literature data about DESs corrosivity has been compared to the data related to the corrosivity of various organic solvents and ionic liquids as well. All the results gained until now show significantly low corrosivity of DESs. This observation is discussed in relation to the chemical composition of DESs. The absence of the oxidizing agents, the inhibitory action of organic ions and molecules, high viscosity and low electrical conductivity have been recognized as the main factors contributing to the low metal corrosion rate in DESs.

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