scholarly journals EXTRACTION AND REEXTRACTION OF HISTIDINE AND RIBOFLAVIN BY N-VINYLCAPROLACTAME COPOLYMERS WITH 1-VINYL- AND 1-METHACRYLOYL-3,5-DIMETHYLPYROZOLE

2018 ◽  
Vol 59 (7) ◽  
pp. 55
Author(s):  
Maria S. Lavlinskaya ◽  
Gennadiy V. Shatalov ◽  
Nadezhda Ya. Mokshina ◽  
Oksana A. Pakhomova ◽  
Vyacheslav A. Kuznetsov
Keyword(s):  
Free Radical ◽  
Uv Spectroscopy ◽  
Aqueous Media ◽  
Radical Copolymerization ◽  
Water Soluble ◽  
Solution Temperature ◽  
Free Radical Copolymerization ◽  
Critical Solution Temperature ◽  
Two Phases ◽  
Degree Of Extraction

Copolymers of N-vinylcaprolactam (VC) with 1-vinyl-3,5-dimethylpyrazole (VDMP) and 1-methacryloyl-3,5-dimethylpyrazole (MDMP) were synthesized by free radical copolymerization  in dioxane with azodiisobutironitrole as initiator. Both water-soluble and water-insoluble copolymers were obtained. The copolymers compositions were determined by FTIR and UV-spectroscopy. The copolymerization constants were calculated and they were: for VC (М1)–VDMP, r1 = 0.65 ± 0.03, r2 = 0.43 ± 0.03; for VC (М1)–MDMP, r1 = 0.79 ± 0.04, r2 = 0.21 ± 0.02. These values show that VC (М1) exhibits somewhat higher activity compared to М2 and that the tendency toward alternation of comonomer units is more pronounced in VC–MDMP copolymers (r1r2 = 0.17) compared to VC–VDMP copolymers (r1r2 = 0.27). It was found that VC–VDMP copolymers are water-soluble at VC content higher than 75 mol %, and VC–MDMP copolymers at VC content higher than 88 mol %. The water-soluble copolymers based on VC have lower critical solution temperature. Their values are in range of 54-69 °C. Two-phases water-salts systems based on synthesized water-soludle thermoresponsive copolymers are proposed for histidine and riboflavin (re)extraction in aqueous media. It was found that extraction systems based on VC-VDMP copolymers are more efficient then VC-MDMP systems. Degree of extraction for both substances in a case of VC-VDMP copolymers achieved 96%. Reextraction carried out by thermoprecipitation of VC (co)polymers. It was shown that reextraction is more efficient at pH 7.6 and its degree achieved 61.7 % for histidine.

Effect of Adding Electrolyte in Cement Paste on the Dispersing Force of Polycarboxylate-Type Superplasticizer

2009 ◽  
Vol 405-406 ◽  
pp. 160-165
Author(s):  
Jun Ying Lai ◽  
Xiao Qian Qian ◽  
Shu Lin Zhan ◽  
Min Hui Fang
Keyword(s):  
Free Radical ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Cement Paste ◽  
Electrolyte Concentration ◽  
Radical Copolymerization ◽  
Water Soluble ◽  
Hydrodynamic Diameter ◽  
Free Radical Copolymerization ◽  
Poly Ethylene

A series of water-soluble polycarboxylate-type superplasticizer (PCA) were synthesized by free-radical copolymerization of methyl acrylic acid and methoxy poly(ethylene glyco1) monoacrylate macromonomers in water solutions．Micelles were formed from the resultant PCA with predetermined hydrophobic and hydrophilic blocks in water. The hydrodynamic diameter and size distribution of micelles were determined by dynamic light scattering. The change of the concentration of the electrolyte results directly in the variation of the dispersing force of PCA in cement paste. The dispersing force degrades with increasing electrolyte concentration.

scholarly journals Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

2010 ◽  
Vol 6 ◽  
Author(s):  
Helmut Ritter ◽  
Beate E Mondrzik ◽  
Matthias Rehahn ◽  
Markus Gallei
Keyword(s):  
Free Radical ◽  
Water Soluble ◽  
Solution Temperature ◽  
Cyclodextrin Complex ◽  
Scanning Calorimetry ◽  
Water Soluble Polymer ◽  
Critical Solution Temperature ◽  
H Nmr ◽  
Nmr Spectrometry ◽  
Cyclodextrin Cavity

We report the radical initiated homopolymerization of a soluble vinylferrocene cyclodextrin-complex in water. Uncomplexed vinylferrocene 1 and the corresponding homopolymer are hydrophobic and completely insoluble in water. Complexation of 1 with methyl-β-cyclodextrin 2 results in clearly water-soluble structures due to incorporation of the ferrocene moiety into the cyclodextrin cavity. After free radical polymerization of the water-soluble complexed monomer, corresponding to polyvinylferrocene (PVFc), the water-soluble polymer is obtained due to the host guest interactions. Those polymeric complexes are stable in water up to about 90 °C. Above this temperature the polymer precipitates due to decomplexation. The complex was investigated by 1H NMR spectrometry, dynamic light scattering (DLS), differential scanning calorimetry (DSC), and lower critical solution temperature (LCST) measurements.

scholarly journals A thermoresponsive poly(ionic liquid) membrane enables concentration of proteins from aqueous media

2016 ◽  
Vol 52 (47) ◽  
pp. 7497-7500 ◽  
Author(s):  
Yuki Kohno ◽  
Douglas L. Gin ◽  
Richard D. Noble ◽  
Hiroyuki Ohno
Keyword(s):  
Ionic Liquid ◽  
Lower Critical Solution Temperature ◽  
Liquid Membrane ◽  
Aqueous Media ◽  
Water Soluble ◽  
Phase Behaviour ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
New Type ◽  
Poly Ionic Liquid

A new type of poly(ionic liquid) membrane, which shows switchable hydrated states via lower critical solution temperature-type phase behaviour, enables concentration of some water-soluble proteins from aqueous media.

High-pressure free-radical copolymerization of ethene and 2-ethylhexyl acrylate

1996 ◽  
Vol 197 (12) ◽  
pp. 4119-4134 ◽  
Author(s):  
Michael Buback ◽  
Thomas Dröge ◽  
Alex Van Herk ◽  
Frank-Olaf Mähling
Keyword(s):  
High Pressure ◽  
Free Radical ◽  
Radical Copolymerization ◽  
Free Radical Copolymerization

scholarly journals Synthesis of a thermoresponsive crosslinked MEO2MA polymer coating on microclusters of iron oxide nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alejandro Lapresta-Fernández ◽  
Alfonso Salinas-Castillo ◽  
Luis Fermín Capitán-Vallvey
Keyword(s):  
Iron Oxide ◽  
Synthesis Temperature ◽  
Water Soluble ◽  
Covalent Attachment ◽  
Solution Temperature ◽  
Tetraethylene Glycol ◽  
Critical Solution Temperature ◽  
Large Size ◽  
Transmission Electron ◽  
Azo Initiator

AbstractEncapsulation of magnetic nanoparticles (MNPs) of iron (II, III) oxide (Fe3O4) with a thermopolymeric shell of a crosslinked poly(2-(2-methoxyethoxy)ethyl methacrylate) P(MEO2MA) is successfully developed. Magnetic aggregates of large size, around 150–200 nm are obtained during the functionalization of the iron oxide NPs with vinyl groups by using 3-butenoic acid in the presence of a water soluble azo-initiator and a surfactant, at 70 °C. These polymerizable groups provide a covalent attachment of the P(MEO2MA) shell on the surface of the MNPs while a crosslinked network is achieved by including tetraethylene glycol dimethacrylate in the precipitation polymerization synthesis. Temperature control is used to modulate the swelling-to-collapse transition volume until a maximum of around 21:1 ratio between the expanded: shrunk states (from 364 to 144 nm in diameter) between 9 and 49 °C. The hybrid Fe3O4@P(MEO2MA) microgel exhibits a lower critical solution temperature of 21.9 °C below the corresponding value for P(MEO2MA) (bulk, 26 °C). The MEO2MA coating performance in the hybrid microgel is characterized by dynamic light scattering and transmission electron microscopy. The content of preformed MNPs [up to 30.2 (wt%) vs. microgel] was established by thermogravimetric analysis while magnetic properties by vibrating sample magnetometry.

Free Radical Copolymerization of Ethylene with Vinyl Acetate under Mild Conditions

2017 ◽  
Vol 50 (9) ◽  
pp. 3516-3523 ◽  
Author(s):  
A. Zarrouki ◽  
E. Espinosa ◽  
C. Boisson ◽  
V. Monteil
Keyword(s):  
Free Radical ◽  
Vinyl Acetate ◽  
Radical Copolymerization ◽  
Free Radical Copolymerization ◽  
Mild Conditions

Synthesis and characterization of hyperbranched associative polyacrylamide

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 39522-39529 ◽  
Author(s):  
Wanfen Pu ◽  
Daijun Du ◽  
Rui Liu ◽  
Jiongyi Gu ◽  
Kewei Li ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Copolymerization ◽  
Synthesis And Characterization ◽  
Functional Monomer ◽  
Free Radical Copolymerization ◽  
Ultrafine Silica ◽  
Hyperbranched Polyamide

HDPAM was synthesized by water free-radical copolymerization based on functional hyperbranched polyamide-modified ultrafine silica as functional monomer.

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