scholarly journals Synthesis of New Fixings of Mobile Sands

2021 ◽  
Vol 36 (1) ◽  
pp. 356-361
Author(s):  
A.I. Sharipova ◽  
I.L. Akhmadjоnov ◽  
A.B. Аbdikamalova ◽  
Kh.I. Akbarov ◽  
Sh.A. Kuldasheva
Keyword(s):  
Moisture Absorption ◽  
Water Soluble ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
Binding Agent ◽  
Negative Effects ◽  
Water Soluble Polymer ◽  
Plastic Strength ◽  
Mechanical Erosion ◽  
Kinetics Of

The issues of the synthesis of a water-soluble polymer preparation, which can find application in agriculture as a structure-forming agent of soils and mobile sands to prevent water, wind, mechanical erosion, increase fertility, moisture absorption, moisture retention, consolidation of soils, dumps, and mobile sands to eliminate negative effects on the environment. Maleic acid and acrylamide were chosen as monomers for the copolymerization reaction, and potassium persulfate was chosen as the initiator. As it turned out, an increase in the concentration of the initiator from 0.01 to 0.05% (by weight of monomers) promotes an increase in the rate of the polymerization process, maintaining its value for a longer time, reducing the time of this process from 7.0-6.5 to 5, 5-6 hours. In this case, the yield of the polymerization reaction increased exactly from 81.2 to 96.0% for the reaction with the ratio of starting materials 1: 5. When a small amount of alkali is introduced into the reaction mixture, high molecular weight polymers can be obtained. In this case, the yield of the process increases, and the reaction time is reduced by 2-3 hours. Analysis of the kinetics of fixing processes using synthesized and various other reagents, as well as changes in the plastic strength of sands, showed the dependence of the conditions of penetration of the fixer with the formation of a free flow in space under the influence of gravitational or capillary forces on the type of binding agent and on the composition of the sand itself.

A sensitive fluorescence method for monitoring the kinetics of microemulsion polymerization

2010 ◽  
Vol 88 (3) ◽  
pp. 185-191 ◽  
Author(s):  
Haike Feng ◽  
Yi Dan ◽  
Yue Zhao
Keyword(s):  
Induction Period ◽  
Sodium Dodecyl ◽  
Fluorescence Emission ◽  
Fluorescence Method ◽  
Water Soluble ◽  
Polymerization Process ◽  
Ionic Surfactant ◽  
Microemulsion Polymerization ◽  
Measurement Results ◽  
Kinetics Of

We present a fluorescence method that allows one to monitor the kinetics of microemulsion polymerization of very low monomer contents (water-to-monomer ratio can readily be superior to 1000). The microemulsion polymerization of methyl methacrylate (MMA) was investigated using N-(2-anthracene)methacrylamide (AnMA) as the probe whose fluorescence emission intensity was proportional to the conversion of MMA into the polymer. The real-time-measurement results show that in the regime of very low monomer contents, the surfactant exerted a profound effect on the kinetic process. In a microemulsion containing 0.1 wt% of MMA with respect to water, with the anionic surfactant of sodium dodecyl sulfate (SDS), the fast polymerization was preceded by an induction period whose length increased with reducing the concentration of the water-soluble initiator of potassium persulfate (KPS). By contrast, with the non-ionic surfactant of polyoxyethylene (20) oleyl ether (Brij98), the induction period was short and the decrease in the KPS concentration mainly resulted in a decrease of the reaction rate. The unprecedented sensitivity of this fluorescence method made it possible to access kinetic data of microemulsion polymerization with very low monomer contents for the first time, providing new insight into the effects of surfactant and initiator on this heterophase polymerization process.

scholarly journals POLYMERIZATION BY INTERACTION a-HALOACRYLIC ACIDS WITH TERTIARY AMINES

2021 ◽  
pp. 890-899
Author(s):  
Юсуф Ахматович Малкандуев ◽  
Анета Ахмедовна Кокоева ◽  
Абдулахат Турапович Джалилов
Keyword(s):  
Spectroscopic Studies ◽  
Nanocomposite Materials ◽  
Water Soluble ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
Tertiary Amines ◽  
Spontaneous Polymerization ◽  
Modified Montmorillonite ◽  
Limiting Stage ◽  
Two Stages

Приведены результаты самопроизвольной полимеризации а -хлоракриловой и а -бромакриловой кислот с третичными аминами при невысокой температуре. В результате самопроизвольной полимеризации при взаимодействии а -галоидакриловых кислот с третичными аминами образуются полимеры, содержащие четвертичные аммониевые группы. С целью подтверждения данного предположения были проведены ЯМР- и ИК-спектроскопические исследования продуктов самопроизвольной полимеризации. Показано, что сопутствующая реакция кватернизации, спонтанной полимеризации, имеет место как в смеси реагентов, так и в присутствии растворителя, т.е. и при смешении непредельного амина и галоидного алкила. Изучены кинетические закономерности реакции полимеризации и показано, что реакция кватернизации, являющаяся лимитирующей стадией процесса самопроизвольной полимеризации, протекает по S 2 - механизму. Описываются первые попытки получения новых нанокомпозиционных материалов на основе синтезированных сополимеров и модифицированного монтмориллонита. Анализ литературных данных показывает, что особенности получения нанокомпозитов на основе Na - монтмориллонита и водорастворимых сополимеров ранее не изучались. The results of spontaneous polymerization of а -chloroacrylic and а -bromoacrylic acids with tertiary amines at a low temperature are presented. As a result of spontaneous polymerization during the interaction of а -halodacrylic acids with tertiary amines, polymers containing quaternary ammonium groups are formed. In order to confirm this assumption, nuclear magnetic resonance and infrared spectroscopic studies of the products of the spontaneous polymerization were carried out. Spontaneous polymerization proceeds, consisting of two stages: the quaternization reaction and the polymerization reaction. The kinetic regularities of the polymerization reaction were studied and it was shown that the quaternization reaction, which is the limiting stage of the spontaneous polymerization process, proceeds according to the S 2 - mechanism. It has described the first attempts to obtain new nanocomposite materials based on synthesized copolymers and modified montmorillonite. Analysis of the literature data shows that the features of the preparation of nanocomposites based on Na - montmorillonite and water-soluble copolymers have not been previously studied.

scholarly journals Enhancement of Separation Efficiency for Nano Filtration Membrane using Water-Soluble Polymer.

2019 ◽  
Vol 8 (2) ◽  
pp. 1470-1474
Keyword(s):  
Heavy Metal ◽  
Flow Rate ◽  
Metal Ion ◽  
Separation Efficiency ◽  
Water Soluble ◽  
Ion Concentration ◽  
Heavy Metal Ion ◽  
Binding Agent ◽  
Water Soluble Polymer ◽  
Filtration Membrane

In this study, an aqueous solution containing a mixture of heavy metal ion Cr(III) were treated by polymer enhanced Nanofiltration using polyethylene glycol as a binding agent polymer. The performance of PEG in removing heavy metal ion Cr (III) was compared with PEG and without PEG addition using polyamide Nano filtrationmembrane. The percentage rejection of heavy metal ions was studied under the different value of pH, metal ion concentration and flow rate. AtpH 10,percentage rejection of heavy metal ion was highest at around 99.2%,whereas,at 200ppm concentration and at 3(l/hm2 )flow rate percentage rejection of heavy metal ion with PEG was highest 99.5%,it was found that PEG gave higher percentage rejection of Cr(III) ion than without the addition of PEG

Paclitaxel-albumin interaction in view of molecular engineering of polymer-drug conjugates

2009 ◽  
Vol 81 (3) ◽  
pp. 439-450 ◽  
Author(s):  
Michael Hess ◽  
Byung-Wook Jo ◽  
Stefan Wunderlich
Keyword(s):  
Anticancer Agent ◽  
Molecular Engineering ◽  
Water Soluble ◽  
Hydrophobic Core ◽  
Water Soluble Polymer ◽  
Polymer Conjugates ◽  
Drug Conjugates ◽  
Model Protein ◽  
Polymer Drug Conjugates ◽  
Kinetics Of

The interaction of water-soluble polymer conjugates of the anticancer agent paclitaxel and albumin as model protein has been investigated using fluorescence spectroscopy and NMR. Drugs and drug conjugates can enter the hydrophobic core of albumin; the kinetics of the interaction with the fluorophore, however, differs. Given the information about the steric situation of the formed complexes, some aspects of molecular engineering of the drug are discussed.

Neurotoxicity and Neuroprotective Effects of Polyimides (PI) and Polyphenylenevinylene (PPV) against Hydrogen Peroxide (H2O2)

2011 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Norfaezah Mazalan ◽  
Mazatulikhma Mat Zain ◽  
Nor Saliyana Jumali ◽  
Norhanim Mohalid ◽  
Zurina Shaameri ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drug Delivery Systems ◽  
Neuronal Cells ◽  
Water Soluble ◽  
Brain Delivery ◽  
Specific Therapy ◽  
Neuroprotective Effects ◽  
Water Soluble Polymer ◽  
Site Specific ◽  
Novel Drugs

Recently, research and development in the field of drug delivery systems (DDS) facilitating site-specific therapy has reached significant progression. DDS based on polymer micelles, coated micro- and nanoparticles, and various prodrug systems including water-soluble polymer have been prepared and extensively studied as novel drugs designed for cancer chemotherapy and brain delivery. Since polymers are going to be used in human, this study has the interest of testing two types of polymer, polyimides (PI) and polyphenylenevinylene (PPV) on neuronal cells. The objective of this study was to determine the possible neurotoxicity and potential neuroprotective effects of PI and PPV towards SH-SY5Y neuronal cells challenged by hydrogen peroxide (H2O2) as an oxidant. Cells were pretreated with either PI or PPV for 1 hour followed by incubation for 24 hour with 100 µM of H2O2. MTS assay was used to assess cell viability. Results show that PI and PPV are not harmful within the concentration up to 10 µM and 100 µM, respectively. However, PI and PPV do not protect neuronal cells against toxicity induced by H2O2 or further up the cell death.

scholarly journals Influence of the Active Layer Structure on the Photovoltaic Performance of Water-Soluble Polythiophene-Based Solar Cells

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1640
Author(s):  
Massimiliano Lanzi ◽  
Debora Quadretti ◽  
Martina Marinelli ◽  
Yasamin Ziai ◽  
Elisabetta Salatelli ◽  
...  
Keyword(s):  
Solar Cells ◽  
Layer Structure ◽  
Photovoltaic Performance ◽  
Phase Segregation ◽  
Water Soluble ◽  
Polymerization Reaction ◽  
Fullerene Derivative ◽  
C60 Fullerene ◽  
Photovoltaic Efficiency ◽  
Single Material

A new side-chain C60-fullerene functionalized thiophene copolymer bearing tributylphosphine-substituted hexylic lateral groups was successfully synthesized by means of a fast and effective post-polymerization reaction on a regioregular ω-alkylbrominated polymeric precursor. The growth of the polymeric intermediate was followed by NMR spectrometry in order to determine the most convenient reaction time. The obtained copolymer was soluble in water and polar solvents and was used as a photoactive layer in single-material organic photovoltaic (OPV) solar cells. The copolymer photovoltaic efficiency was compared with that of an OPV cell containing a water-soluble polythiophenic homopolymer, functionalized with the same tributylphosphine-substituted hexylic side chains, in a blend with a water-soluble C60-fullerene derivative. The use of a water-soluble double-cable copolymer made it possible to enhance the control on the nanomorphology of the active blend, thus reducing phase-segregation phenomena, as well as the macroscale separation between the electron acceptor and donor components. Indeed, the power conversion efficiency of OPV cells based on a single material was higher than that obtained with the classical architecture, involving the presence of two distinct ED and EA materials (PCE: 3.11% vs. 2.29%, respectively). Moreover, the synthetic procedure adopted to obtain single material-based cells is more straightforward and easier than that used for the preparation of the homopolymer-based BHJ solar cell, thus making it possible to completely avoid the long synthetic pathway which is required to prepare water-soluble fullerene derivatives.

scholarly journals Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

2021 ◽  
Author(s):  
Aranee Pleng Teepakakorn ◽  
Makoto Ogawa
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

scholarly journals Synthesis of poly (n-butyl acrylate) with tempo by nitroxide mediated polymerization method

2021 ◽  
pp. 096739112110245
Author(s):  
Amrita Sharma ◽  
PP Pande
Keyword(s):  
Butyl Acrylate ◽  
Low Cost ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
High Concentration ◽  
Acrylate Monomer ◽  
Controlled Polymerization ◽  
Acrylate Monomers ◽  
Nitroxide Mediated Polymerization ◽  
Polymerization Method

It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly ( n-butyl acrylate) viz. polystyrene-block-poly-( n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.

Sign in / Sign up

Export Citation Format

Share Document