Showing papers on "Acrylic acid published in 2000"
TL;DR: In this paper, a shell cross-linked knedel-like nanoparticles (SCKs) possessing an amphiphilic core−shell morphology consisting of a crosslinked shell and a hydrolytically degradable, crystalline core domain were synthesized from poly(e-caprolactone)-b-poly(acrylic acid) (PCL-b-PAA) copolymers via a two-step process.
Abstract: Shell cross-linked knedel-like nanoparticles (SCKs) possessing an amphiphilic core−shell morphology consisting of a cross-linked shell and a hydrolytically degradable, crystalline core domain were synthesized from poly(e-caprolactone)-b-poly(acrylic acid) (PCL-b-PAA) amphiphilic diblock copolymers via a two-step process: self-assembly of PCL-b-PAA into polymer micelles followed by cross-linking of the hydrophilic shell layer via condensation reactions between the carboxylic acid functionalities of PAA and the amine groups of 2,2‘-(ethylenedioxy)bis(ethylamine). PCL-b-PAA was prepared from the selective hydrolysis of a poly(e-caprolactone)-b-poly(tert-butyl acrylate) (PCL-b-PtBA) precursor, which was synthesized by ring opening polymerization (ROP) of e-caprolactone (e-CL) followed by atom transfer radical polymerization (ATRP) of tert-butyl acrylate (tBA). Selective hydrolysis of the tert-butyl ester groups of the PtBA block by reaction with trimethylsilyl iodide (TMSI), followed by reaction with aqueous...
365 citations
TL;DR: In this paper, a series of monodisperse PNIPAM/AAc microgels with different content of acrylic acid were synthesized by surfactant-free emulsion polymerization employing sonication instead of a conventional stirring technique.
345 citations
TL;DR: In this article, the formation of the nacre of a shell is mimicked to synthesize layered polymer/calcium carbonate composites such as that shown in the Figure, where the combination of insoluble chitin or chitosan solid matrices with soluble acidic macromolecules such as poly(acrylic acid) is used to induce thin-film crystallization of CaCO3 on the solid matrix.
Abstract: Formation of the nacre of a shell is mimicked here to synthesize layered polymer/calcium carbonate composites such as that shown in the Figure. The combination of insoluble chitin or chitosan solid matrices with soluble acidic macromolecules such as poly(acrylic acid) is used to induce thin-film crystallization of CaCO3 on the solid matrices. The polymorph formed can also be controlled employing this method.
236 citations
TL;DR: In this article, a cross-linked polyacrylic acid (PAA) hydrogel was synthesized using a two-step method and the swelling behavior of the gels was studied as a function of the concentration of PAA in aqueous solution during γ-irradiation, radiation dose and pH of the swelling medium.
220 citations
TL;DR: In this article, the influence of polyelectrolyte on the lower critical solution temperature (LCST) of temperature/pH sensitive hydrogels was investigated in the pH range of 2∼12.
180 citations
TL;DR: In this article, selective oxidations of ethane to ethene and acetic acid and of propane to acrylic acid were carried out over hydrothermally synthesized Mo-V-M-O (M=Al, Ga, Bi, Sb and Te) complex metal oxide catalysts.
Abstract: Selective oxidations of ethane to ethene and acetic acid and of propane to acrylic acid were carried out over hydrothermally synthesized Mo-V-M-O (M=Al, Ga, Bi, Sb, and Te) complex metal oxide catalysts. All the synthesized solids were rod-shaped crystallites and gave a common XRD peak corresponding to 4.0 A d -spacing. From the different XRD patterns at low angle region below 10° and from the different shape of the cross-section of the rod crystal obtained by SEM, the solids were classified into two groups: Mo-V-M-O (M=Al, possibly Ga and Bi) and Mo-V-M-O (M=Sb, and Te). The former catalyst was moderately active for the ethane oxidation to ethene and to acetic acid. On the other hand the latter was found to be extremely active for the oxidative dehydrogenation. The Mo-V-M-O (M=Sb, and Te) catalysts were also active for the propane oxidation to acrylic acid. It was found that the grinding of the catalysts after heat-treatment at 600°C in N 2 increased the conversions of propane and enhanced the selectivity to acrylic acid. Structural arrangement of the catalytic functional components on the surface of the cross-section of the rod-shaped catalysts seems to be important for the oxidation activity and selectivity.
166 citations
TL;DR: Graft copolymerizations of acrylamide and/or acrylic acid onto cassava starch by a simultaneous irradiation technique using gamma-rays as the initiator were studied with regard to various parameters of importance as discussed by the authors.
158 citations
TL;DR: In this article, a multilayer self-assembly technique was used to combine DAR and poly(acrylic acid) polyanion structures using the layer-by-layer selfassembly technique.
Abstract: Diazo-resins (DAR) as polycation and poly(acrylic acid) (PAA) as polyanion were alternately assembled into a multilayer structure by using the layer-by-layer self-assembly technique. PAA as a weak ...
128 citations
TL;DR: In this article, the authors investigated the solution properties and the phase behaviour of random copolymers of N -isopropylacrylamide (NIPAM) with acrylic acid (AA).
126 citations
TL;DR: Pulsed laser-induced polymerization in combination with analysis of formed polymer by size exclusion chromatography (SEC) has been successfully applied in determining propagation rate coefficient, kp, of acrylic and methacrylic acid in organic solvents and water as discussed by the authors.
Abstract: Pulsed laser-induced polymerization (PLP) in combination with analysis of formed polymer by size exclusion chromatography (SEC) has been successfully applied in determining propagation rate coefficient, kp, of acrylic and methacrylic acid in organic solvents and water. For methacrylic acid solution polymerization in methanol and in dimethyl sulfoxide (DMSO), minor but not negligible variations of kp with solvent have been observed. In contrast, kp values for polymerizations in water are significantly influenced by the solvent and furthermore by monomer concentration. The kp values obtained from polymerization experiments in water are significantly larger than the corresponding values obtained in methanol or DMSO. Weighted nonlinear least-squares fitting (NLLS) has been applied to calculate frequency factors, A, and activation energies, Ea, from the temperature dependence of kp for methacrylic acid in methanol, DMSO, and water in order to underline the reliability of the data. For acrylic acid it turns out...
121 citations
TL;DR: In this article, a large number of carboxylic groups were introduced onto chitosan by grafting with poly(acrylic acid) as an efficient way of modification.
Abstract: A large number of carboxylic groups were introduced onto chitosan by grafting with poly(acrylic acid) as an efficient way of modification. The reactions were carried out in a homogeneous aqueous phase by using potassium persulfate and ferrous ammonium sulfate as the combined redox initiator system. The efficiency of grafting was found to depend on monomer, initiator, and ferrous ion concentrations as well as reaction time and -temperature. It was observed that the level of grafting could be controlled to some degree by varying the amount of ferrous ion used as a co-catalyst in the reaction. Evidence of grafting was obtained by comparison of FTIR spectra of chitosan and the graft copolymer as well as solubility characteristics of the products. The swelling behavior of chitosan samples, grafted with 115% and 524% poly(acrylic acid), was studied as function of pH, in distilled water and in aqueous NaCl solution. The sample that has 115% grafting swells considerably more both in distilled water (pH 5.8) as well as higher pH values than the sample with 524% grafting. In contrast, an inverse swelling behavior at pH 2 was observed. An unusual swelling behavior at pH 2 was found for the sample with 524% grafting, which swells to a greater extent than in distilled water. This was attributed to the amphiphilic nature of the modified chitosan from which complex inter- and/or intramolecular interactions could originate.
TL;DR: Aqueous acrylic-polyurethane hybrid emulsions were prepared by semi-batch emulsion polymerization of a mixture of acrylic monomers (butyl acrylate, methyl methacrylate and acrylic acid) in the presence of polyurehane dispersion.
Abstract: Aqueous acrylic-polyurethane hybrid emulsions were prepared by semi- batch emulsion polymerization of a mixture of acrylic monomers (butyl acrylate, methyl methacrylate, and acrylic acid) in the presence of polyurethane dispersion Equivalent physical blends were prepared by mixing acrylic emulsion and polyurethane dispersion The weight ratio between acrylic and polyurethane components varied to obtain differ- ent emulsion properties, microphase structure, and mechanical film properties of hy- brid emulsions and physical blends Particle size and molecular mass measurements, scanning electron microscopy, glass transition temperature, and rheological measure- ments performed characterization of the latex system The mechanical properties were investigated by measuring tensile strength and Koenig hardness of dried films The experimental results indicate better acrylic-polyurethane compatibility in hybrid emul- sions than in physical blends, resulting in improved chemical and mechanical proper- ties © 2000 John Wiley & Sons, Inc J Appl Polym Sci 78: 67- 80, 2000
TL;DR: In this paper, copolymers of N-isopropylacrylamide and acrylic acid were prepared in benzene with varying contents of acrylic acid (0 to 3%) and the thermal properties were evaluated.
Abstract: To improve the properties of a reversible syn- thetic extracellular matrix based on a thermally reversible polymer, copolymers of N-isopropylacrylamide and acrylic acid were prepared in benzene with varying contents of acrylic acid (0 to 3%) and the thermal properties were evalu- ated. The poly(N-isopropylacrylamide) and copolymers made with acrylic acid had molecular weights from 0.8 to 1.7 ◊10 6 D. Differential scanning calorimetry (DSC) showed the high-molecular-weight acrylic acid copolymers had similar onset temperatures to the homopolymers, but the peak width was considerably increased with increasing acrylic acid content. DSC and cloud point measurements showed that polymers with 0 to 3% acrylic acid exhibit a lower criti- cal solution temperature (LCST) transition between 30° and 37°C. In swelling studies, the homopolymer showed signifi- cant syneresis at temperatures above 31°C. Copolymers with 1 and 1.5% showed syneresis beginning at 32° and 37°C, respectively. At 37°C the copolymers with 1.5-3% acrylic acid showed little or no syneresis. Due to the high water content and a transition near physiologic conditions (below 37°C), the polymers with 1.5-2.0% acrylic acid exhibited properties that would be useful in the development of a refillable synthetic extracellular matrix. Such a matrix could be applied to several cell types, including islets of Langer- hans, for a biohybrid artificial pancreas. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 51, 69-79, 2000.
TL;DR: In this article, an active carbon-supported catalysts were used for catalytic wet air oxidation (CWAO) of phenol and of acrylic acid (160°C and 20 bar of O2).
Abstract: Ru/C catalysts promoted, or not, by cerium were prepared by impregnation of an active carbon (961 m2 g−1) with chlorine-free precursors of Ru and Ce. They were characterized by chemisorption of H2 and of CO and by electron microscopy. TEM and H2 chemisorption gives coherent results while CO chemisorption overestimates Ru dispersion. In Ru–Ce/C, Ce is in close contact with Ru and decreases Ru accessibility. Catalytic wet air oxidation (CWAO) of phenol and of acrylic acid (160°C and 20 bar of O2) was investigated over these catalysts and their performance (activity, selectivity to intermediate compounds) compared with that of a reference Ru/CeO2 catalyst. Carbon-supported catalysts were very active for the CWAO of phenol but not for acrylic acid. Although high conversions were obtained, phenol was not totally mineralized after 3 h. It was shown that acrylic acid was more strongly adsorbed than phenol. Moreover, the number of contact points between Ru particles and CeO2 crystallites constitutes a key parameter in these reactions. A high surface area of ceria is required to insure O2 activation when the organic molecule is strongly adsorbed.
TL;DR: In this paper, the authors show that complexation of cationic fluorosurfactants to well-defined acrylic acid plasma polymer surfaces gives rise to oleophobic/hydrophilic behavior.
Abstract: Complexation of cationic fluorosurfactants to well-defined acrylic acid plasma polymer surfaces gives rise to oleophobic/hydrophilic behavior. This is in marked contrast to the usual oleophobic/hydrophobic liquid repellent attributes of conventional polyelectrolyte−fluorosurfactant complexes formed by solution-phase synthesis.
TL;DR: In this paper, thin organic films were deposited from plasmas of allyl alcohol, acrylic acid, allylamine, and octa-1,7-diene onto aluminum substrates.
Abstract: Thin organic films were deposited from plasmas of allyl alcohol, acrylic acid, allylamine, and octa-1,7-diene onto aluminum substrates. These plasma polymerized films were analyzed by X-ray photoel...
TL;DR: In this article, the formation of graft copolymers was confirmed by gravimetric measurement, acid hydrolysis and IR spectroscopy, and the activation energies at every stage of decomposition for all the polymer samples were determined from their primary thermograms.
Abstract: The graft copolymers of pure granular maize starch with acrylamide, methacrylamide, acrylic acid and methacrylonitrile were synthesized using ceric ammonium nitrate as an initiator. The formation of graft copolymer was confirmed by gravimetric measurement, acid hydrolysis and IR spectroscopy. The thermal analysis of the pure granular maize starch and graft copolymers was carried out using thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), differential scanning calorimetry (DSC), differential thermal analysis (DTA) and isothermal analysis. In order to determine the mechanism of decomposition of these polymers, the isothermal analysis was coupled with IR spectroscopy. The activation energies at every stage of decomposition for all the polymer samples were determined from their primary thermograms. The glass transition temperatures (T g ) for pure granular maize starch and all the graft copolymers have been reported. Except starch-graft-acrylic acid, all other graft copolymers showed enhanced thermal stability over pure starch. T g of pure starch was observed as 91 °C. All the graft copolymers showed lower values of T g with a minimum of 57 °C for starch-graft-methacrylonitrile. DTA studies indicated a delayed oxidative degradation of graft copolymers.
TL;DR: In this article, a hybrid miniemulsion polymerization with acrylic monomers (methyl methacrylate, butyl acrylate and acrylic acid) in the presence of oil-modified polyurethane resin was carried out.
Abstract: As part of a wider effort to develop a new class of waterborne coatings, hybrid miniemulsion polymerization was carried out with acrylic monomers (methyl methacrylate, butyl acrylate, and acrylic acid) in the presence of oil-modified polyurethane resin. Latexes with different ratios of resin to acrylic monomers were synthesized. The monomer emulsions prepared for hybrid miniemulsion polymerization showed excellent shelf-life stability (>5 months) and the polymerization was run free of coagulation. Solvent extraction indicated that the grafting efficiency of polyacrylics was greater than 29% for all the samples produced. A 13C solution NMR spectrum showed that a substantial fraction of the original carbon double bonds (>61%) in oil-modified polyurethane remained after polymerization for film curing. Films obtained from the latexes presented good adhesion properties and fair hardness properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 105–114, 2000
TL;DR: The homopolymer proportion in the enzymatically produced grafts of Ca-LS and acrylic acid was 5 to 6x lower than those initiated by the Fenton-like reagent; no such differences were observed for Na-LS.
Patent•
28 Feb 2000
TL;DR: In this article, a process for the catalytic gas-phase oxidation of propene to acrylic acid is described, in which the reaction gas starting mixture is oxidized, with a high propene loading, in a first reaction stage, over a first fixed-bed catalyst which is housed in two successive reaction zones A, B, the reaction zone B being at a higher temperature than the reaction Zone A, A, and the acrolein-containing product gas mixture of the reaction stage is then oxidized in a second reaction stage.
Abstract: A process for the catalytic gas-phase oxidation of propene to acrylic acid, in which the reaction gas starting mixture is oxidized, with a high propene loading, in a first reaction stage, over a first fixed-bed catalyst which is housed in two successive reaction zones A, B, the reaction zone B being kept at a higher temperature than the reaction zone A, and the acrolein-containing product gas mixture of the first reaction stage is then oxidized in a second reaction stage, with a high acrolein loading, over a second fixed-bed catalyst which is housed in two successive reaction zones C, D, the reaction zone D being kept at a higher temperature than the reaction zone C.
TL;DR: In this paper, graft copolymers were synthesized by free radical copolymerization of AAc with PDMAAm macromonomer, and they were shown to be water-soluble at lower temperatures, while they showed a liquid−liquid phase separation from water above the characteristic transition temperatures.
Abstract: To investigate the influence of molecular architecture of poly(acrylic acid) (PAAc)-graft-poly(N,N-dimethylacrylamide) (PDMAAm) (PAAc-g-PDMAAm) on its solution properties in aqueous media, graft copolymers were synthesized by free radical copolymerization of AAc with PDMAAm macromonomer. PAAc-g-PDMAAms were water-soluble at lower temperatures, while they showed a liquid−liquid phase separation from water above the characteristic transition temperatures. The phase transition behavior was affected by the copolymer compositions and pH of the solution. Below the transition temperature, hydrogen-bonding formation between AAc and DMAAm units was observed in the PAAc-g-PDMAAm aqueous solution by FT-IR−ATR measurement. Graft copolymers were thus formed spherical associates with a diameter of ca. 150 nm estimated from the dynamic light scattering measurement. At higher temperatures, the dehydrated regions and the weak dehydration of the PDMAAm chains induced cooperatively the hydrophobic aggregation, resulting in ...
TL;DR: In this paper, composite films consisting of metallic Cu nanoparticles dispersed in poly(acrylic acid) (PAA) have been prepared by reduction of Cu2+ ions from the copper salt of PAA above 220°C under a H2======
Abstract: Composite films consisting of metallic Cu nanoparticles dispersed
in poly(acrylic acid) (PAA) have been prepared by reduction of Cu2+
from the copper salt of PAA above 220 °C under a H2
atmosphere. Optical absorption properties and structures have also been investigated
by UV/VIS, WAXD, TEM and IR. Spherical Cu particles were found to be homogeneously
dispersed in the PAA and the diameters of the particles were in the range
10–16 nm. The composite films exhibited an optical absorption
peak centered at ca. 570 nm, which was attributed to surface
plasmon resonance of Cu nanoparticles. The composite film made by heat treatment
at 220 °C was less stable because Cu particles in the film were
oxidized to Cu2+ ions within several weeks, while the composite
films prepared by heating above 230 °C were stable and the Cu particles
in their films were not oxidized. The stability of the Cu nanoparticles in
PAA is suggested to be related to the formation of ketone groups by condensation
reactions between carboxylic acids of PAA above 230 °C.
TL;DR: In this paper, a kinetic study of seeded emulsion polymerization using seed latices electrosterically stabilized with poly(acrylic) acid was performed, where data were obtained at 50 °C for the steady-state rate of polymerization initiated with persulfate and for the non-steady-state relaxation initiated using γ-radiolysis; conditions were chosen so the system obeyed ''zero-one'' kinetics (when entry of a radical into a particle already containing a growing radical leads to instantaneous termination).
Abstract: A kinetic study of seeded emulsion polymerization using seed latices electrosterically stabilized with poly(acrylic) acid was performed. Data were obtained at 50 °C for the steady-state rate of polymerization initiated with persulfate and for the non-steady-state relaxation initiated using γ-radiolysis; conditions were chosen so the system obeyed `zero-one' kinetics (when entry of a radical into a particle already containing a growing radical leads to instantaneous termination). The relaxation data directly measure the rate coefficient k for radical exit (desorption) from particles, which in combination with the steady-state rate then yields the rate coefficient for radical entry, ρ. Electrosterically stabilized particles were synthesized from well-characterized seed (made with ionic surfactant) by second-stage polymerization of a small amount of styrene and acrylic acid. Two degrees of surface coverage were employed using 5 and 15 wt % acrylic acid. The low-coverage particles were much more colloidally stable than the polystyrene latices stabilized by initiator fragments and adsorbed surfactant but the behavior of k and ρ was the same as that of the ionically stabilized seed. The colloidal stability of the high-coverage latices was strongly pH-dependent, with high stability at high pH. These latices exhibited strongly reduced k (by a factor of about 3) at low pH but ρ was only slightly lower compared to the ionically stabilized seed. At high and neutral pH, kinetic parameters could not be determined for the highly covered particles because of secondary nucleation; however, a decreased rate was observed with increasing pH, despite an increase in particle number, indicating a reduced ρ. Thus, extensive electrosteric stabilizer seems to reduce entry and exit rate coefficients, although to a lesser extent than reported in an earlier preliminary study. For sparsely electrosterically stabilized particles, the dependences of ρ and k on particle size and (for ρ) initiator concentration were in accord both with those observed for ionically stabilized ones and with the values predicted from models for these processes (transfer diffusion for k and `propagation to z-mer' for ρ).
TL;DR: Hybrid miniemulsion polymerization was performed with a three-component acrylic system of methyl methacrylate, butyl acrylate and acrylic acid in the presence of a Bayer® Roskydal TPLS2190 unsaturated polyester resin this paper.
Abstract: Hybrid miniemulsion polymerization was performed with a three-component acrylic system of methyl methacrylate, butyl acrylate, and acrylic acid in the presence of a Bayer® Roskydal TPLS2190 unsaturated polyester resin. Latexes were obtained in which the polyester resin was grafted to the acrylic polymer, forming a water-based crosslinkable coating. Grafting between the resinous component and the acrylic polymer is a feature different from the work of others who have attempted to combine the properties of both systems in water-based blends. Both emulsions and latexes were shelf-stable for over 6 months, shear-stable, and resistant to at least one freeze/thaw cycle. Resin-to-monomer ratios were studied as high as 1 : 1 (wt : wt), and total emulsion solids, as high as 45%. Monomer droplet and latex particle sizes were similar, suggesting evidence of the preponderance of droplet nucleation. A high level of crosslinking (>70%) during polymerization was observed in this particular hybrid system in contrast to those involving alkyd or polyurethane resins (<5%). Films, both homogeneous and hard, were achieved with exceptional adhesion. Electron microscopy showed the hybrid particle morphology to have internal domains of polyester resin in an acrylic matrix. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 916–927, 2000
TL;DR: In this paper, the stability of water-in-CO2 (W/C) emulsions with poly(dimethylsiloxane)-b-poly(methacrylic acid) (PDMS-b-PMA) and PDMS b-polypoly(acrylic acids) (PAA) ionomer surfactants is reported as a function of surfactant architecture, pH, temperature, pressure, and droplet flocculation.
Abstract: The stability of water-in-CO2 (W/C) emulsions stabilized with poly(dimethylsiloxane)-b-poly(methacrylic acid) (PDMS-b-PMA) and PDMS-b-poly(acrylic acid) (PDMS-b-PAA) ionomer surfactants is reported as a function of surfactant architecture, pH, temperature, pressure, and droplet flocculation. For a given PDMS block length, the stability of the emulsion is correlated with the distance from the balanced state where the surfactant prefers the water and CO2 phases equally. When the pH starting at 3 is raised up to 5−6, the hydrophilic/CO2-philic balance of the surfactant increases, because of ionization of COOH, and the emulsion becomes more stable. At the pH of maximum stability, the emulsion becomes more stable with a decrease in the PDMS length, for a given ratio of block lengths, because of gelation of the flocculated 2−5 μm primary droplets. W/C emulsions are stable with respect to sedimentation for >24 h and are resistant to coalescence for more than 7 days. Because of gelation, the W/C emulsions are mor...
TL;DR: In this article, the surface of ground calcium carbonate has been modified with several unsaturated acids and acid anhydrides of varying molecular weight The modified calcium carbonates were then compounded with polypropylene, both in the presence and absence of dicumyl peroxide as an initiator, through twin screw extrusion to give compounds containing 75 phr of filler.
TL;DR: In this article, epoxy urethane acrylates were prepared from epoxy resins, acrylic acid and 4,4′-diphenylmethane diisocyanate using two-stage polymerization.
TL;DR: In this paper, the effect of anionic polyelectrolytes on the electrokinetic and rheological properties of concentrated Si 3 N 4 suspensions was investigated experimentally.
Abstract: The effect of anionic polyelectrolytes on the electrokinetic and rheological properties of concentrated Si 3 N 4 suspensions was investigated experimentally. We found that polyelectrolyte adsorption and, thus, colloidal stability at pH>pH Si 3 N 4 iep is mainly governed by the surface charge density of the solid phase. Comparing anionic methacrylic acid comb copolymer modifications with grafted poly(ethylene oxide) chains (PMMA-PEO), with poly(acrylic acid) (PAA) showed that the grafted PEO chains have a minor influence on the colloidal stability. The common viscosity minimum for all the anionic polyelectrolytes around pH 7 suggests that the suspensions are electrosterically stabilized. The polyacrylic backbone attains an extended conformation perpendicular to the surface. The effect of excess addition of polyelectrolyte was also discussed; we attribute the significant increase in suspension viscosity to the increased ionic strength caused by the release of associated counterions of the polymer functional groups.
TL;DR: In this article, the effects of low-molecular-weight additives, temperature and mechanical action on the structure and properties of starch are discussed, and special attention is given to mixtures of starch with synthetic polymers, e.g., co-polymers of ethylene with vinyl acetate, vinyl alcohol, acrylic acid, cellulose derivatives and other natural polymers.
Abstract: The effects of low-molecular-weight additives, temperature and mechanical action on the structure and properties of starch are discussed. Special attention is given to mixtures of starch with synthetic polymers, e.g., co-polymers of ethylene with vinyl acetate, vinyl alcohol, acrylic acid, cellulose derivatives and other natural polymers. These mixtures can be used in the development of novel environmentally safe materials (films, coatings, packaging materials) and various articles for short-term use. The bibliography includes 105 references.
TL;DR: In this article, the effects of sodium dodecyl sulfate (SDS) on surface tension and rheology of aqueous solutions of an associative polymer, poly(ethylene oxide)−b-poly(propylene oxide),−b-(poly(methylene oxide))−g-poly (acrylic acid) (Pluronic-PAA) have been studied.
Abstract: Effects of sodium dodecyl sulfate (SDS) on surface tension and rheology of aqueous solutions of an associative polymer, poly(ethylene oxide)−b-poly(propylene oxide)−b-(poly(ethylene oxide))−g-poly(acrylic acid) (Pluronic-PAA) have been studied. SDS starts to bind to the Pluronic-PAA copolymer at a concentration that is 25-fold lower than the critical micellization concentration (CMC) of the surfactant. The data indicate predominant binding between SDS and polyether segments of Pluronic-PAA. Incorporation of SDS into the Pluronic micelles makes the polymer less surface-active, as the surface tension increases. The Pluronic-PAA chains collapse when SDS binds, because the surfactant enhances hydrophobic intramolecular associations.