Acid Acrylamide Research Articles

Resistance‐based switching humidity property of crosslinked acrylic acid–acrylamide copolymers and their ionization effect against the critical humidity

AbstractThe resistance‐based switching humidity property of crosslinked acrylic acid–acrylamide copolymers was measured with an LCZ meter, and their ionic mobilities, which varied with humidity, were measured by the polar‐inversion method. Their conduction mechanism was discussed, and it was found that the ionization effect of some binding ions against a critical humidity takes place in switchable humidity‐sensitive materials. The effect is that some binding ions in materials turn into free ions when a given ambient humidity, called a critical humidity, is reached. The avalanching‐conduct electricity then occurs in materials. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1057– 1060, 2002

Synthesis of New Sulfonic Acid Acrylamide Derivative from Acrylonitrile, Camphene, and Oleum

Synthesis of New Sulfonic Acid Acrylamide Derivative from Acrylonitrile, Camphene, and Oleum

Synthesis of cyclic RGD derivatives via solid phase macrocyclization using the Heck reaction

A novel intramolecular macrocyclization reaction on a solid support using the Heck reaction has been achieved. For head to tail cyclization on a solid support, the linear precursor was anchored to a chlorotrityl chloride resin via an ester linkage using the β-carboxyl group of Asp. The Heck coupling of acrylic acid amide to 3-iodobenzylamine on the solid support proceeds smoothly to yield a cyclic tetrapeptide derivative, which contains a new 3-substituted cinnamic acid template and Arg-Gly-Asp sequence. The macrocyclization reaction takes place considerably more rapidly on a solid support than in solution. The solid phase procedure was successfully used for the construction of cyclic RGD libraries having diverse side chain structures, combined with a variety of ring sizes.

Diastereo- and enantioselective hydrodimerization of β-monosubstituted acrylic acid amides induced by chiral samarium(II) complexes

The chiral samarium(II) complex prepared from SmI2, (R)-BINOL, and an achiral tertiary amine promoted the reductive homo-coupling reaction of β-monosubstituted acrylic acid amides to give the corresponding 3,4-trans-disubstituted adipamides with high enantioselectivities (up to 85% ee).

Preparation of new membranes by complex formation of itaconic acid–acrylamide copolymer with polyvinylpyrrolidone: studies on gelation mechanism by light scattering

Mechanism of membrane formation by dipping a 10 wt% aqueous homogeneous polymer solution of poly(itaconic acid– co-acrylamide) (75:25 molar ratio)/polyvinylpyrrolidone (50/50) into acid solution was investigated by time-resolved light scattering and the pH effect of the acid solution to gelation mechanism during membrane formation was discussed. In the pH range 1.58–1.25, the gelation was governed by phase separation mechanism via the spinodal decomposition and then a membrane with regular pore size was obtained. The phase separation was caused by polymer–polymer complex formation between polymers. From an analysis based on Cahn's linearized theory of the spinodal decomposition, the apparent diffusion coefficient D app of phase separation was smaller for lower pH. Because, at low pH there exists a lot of complex which dramatically reduces the chain mobility. The average pore size of membrane also depends on pH. When the pH was lower than 1.25, the liquid–liquid phase separation did not occur but the solution gelled homogeneously and a wrinkle-like morphology without pore was observed. FTIR analysis of the dried membranes showed that the complex formation had occurred by hydrogen bonding between the component polymers and its extent increased linearly with decreasing pH.

Synthesis of deoxy(thiosulfato)chitin as the precursor for noncatalytic photoinduced graft copolymerization

Photoinduced graft copolymerization of vinyl monomers onto deoxy(thiosulfato)chitin (S2O3–chitin) has been studied. Chitin was first tosylated and subsequently transformed into S2O3–chitin. S2O3–chitin has good solubility over tosyl–chitin. Graft copolymerization of S2O3–chitin proceeded very easily by ultraviolet irradiation without catalyst. Photolysis of S2O3 groups was confirmed by infrared spectra. But the photolysis occurred only in quartz, not in a Pyrex tube. Methyl methacrylate (MMA) and acrylonitrile showed good grafting activities. In the case of acrylic acid and acryl amide, homopolymer formation was predominant, and the degree of grafting was low. We chose the MMA monomer for further information. The grafting rate of S2O3–chitin using MMA was much faster than those of chitin and O-acetyl–chitin. Under the appropriate conditions, the degree of grafting reached 600% only in 2 h, and the grafting efficiency was over 75% in any monomer concentration. But addition of DMSO into the polymerization system decreased the degree of grafting. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 189–195, 1999

Macrocyclization on solid support using Heck reaction

A novel intramolecular macrocyclization reaction on solid support using Heck reaction was achieved. The Heck coupling of acrylic acid amide to 3-iodobenzylamine on solid support proceeds smoothly to yield a cyclic tetrapeptide derivative containing a new 3-substituted cinnamic acid template and Arg-Gly-Asp sequence. The macrocyclization reaction takes place more rapidly on solid support than in solution.

Fluorescence Properties of Polyacrylic Acid Derivative - Eu3+ Ion - Low Molecular Ligand Complexes

The polyacrylic acid derivative, the copolymer (PABAM) of acrylic acid (AA) and p-benzoic acid acrylamide (BAM) were prepared by polymeric reaction. The coordinate structure of the polymer–Eu3+ complexes was characterized by X-ray photoelectron spectroscopy. The fluorescence intensity of the PABAM–Eu3+ complex was enhanced because of introduction of a BAM unit in the polyacrylic acid and reached a maximum when the mole ratio of AA to BAM was about 1 : 1. The ternary complexes of Eu3+–polymer–1,10-phenanthroline (PRL), or 2,2-bipyridine (BPD) were synthesized. The polymers used were PABAM and polyacrylic acid (PAA). The fluorescence intensity of the polymer–Eu3+ complexes was increased by 5∼21 times owing to the introduction of PRL and BPD.

Suppression of Influenza Virus Infection by an N-Thioacetylneuraminic Acid Acrylamide Copolymer Resistant to Neuraminidase

We have previously shown that α-2-O-methyl-5-N-thioacetylneuraminic acid (α-Neu5thioAc2Me) has a higher affinity to bromelain-treated hemagglutinin (HA) of influenza A virus than sialic acid from natural sources (Machytka et al., 1993, FEBS Lett. 334, 117-120). We have now compared the inhibitory effects of α-Neu5thioAc2Me and other sialic acid analogs on receptor binding and plaque formation of intact influenza A viruses. When α-Neu5thioAc2Me was polymerized by conjugation to polyacrylamide, its affinity to HA increased 103-fold. When analyzed by plaque reduction, the α-Neu5thioAc2 polymer was about 10 times more efficient as an inhibitor of virus replication than the α-Neu5Ac2 polymer, stressing the importance of sulfur at C5. The S-glycoside α-2-S-methyl-5-N-thioacetylneuraminic acid (α-Neu5thioAc2SMe) had the same affinity to HA as α-Neu5thioAc2Me, but was resistant to neuraminidase. The α-Neu5thioAc2S polymer interfered with the replication of a wider spectrum of influenza A virus subtypes than the α-Neu5thioAc2 polymer. The results indicate that the αNeu5thioAc2S polymer has the potential to be used as an inhibitor of influenza virus infection.

Methacrylic acid–acrylamide‐g‐poly(ethyleneterephthalate) fibres for urea hydrolysis

AbstractThis paper presents the results of urease immobilization onto methacrylic acid–acrylamide grafted poly(ethyleneterephthalate) fibres. The graft yield strongly affected the maximum activity of the immobilized enzyme up to a value of 70·2%. Higher grafting caused a decline in urease activity and led to the degradation of the fibres. The minor changes observed in Km and Vmax demonstrated that the conformational changes existed during immobilization were not extensive. However, 70·2% methacrylic acid–acrylamide‐g‐fibres containing urease were more stable towards acidic and alkaline pH, high temperature and storage conditions compared with free enzyme. Apart from the increase in stability to heat inactivation, the initial enzymatic activity of the urease–fibre system remained almost unchanged even after 40 repeated assays corresponding to 10 h of operation in 4 months, indicating the excellent durability of the system.

Interaction between drugs and pressure-sensitive adhesives in transdermal therapeutic systems.

Release experiments with four drugs using representative pressure-sensitive adhesive (PSA) matrices were performed at 37 degrees C, and drug-PSA polymer interaction was determined by the Williams, Landel, and Ferry (WLF) equation. Two acrylic-type [2-ethylhexylacrylate and acrylic acid copolymer (2EHA/AA) or acrylamide copolymer (2EHA/AAm)], one rubber-type (a mixture of high and low molecular weight polyisobutylene), and one silicone-type PSA were used, and dipropylphthalate (PP), aminopyrine (AMP), ketoprofen (KP), and lidocaine (LC) were selected as model drugs because of their molecular size and functional groups. PSA containing acrylic acid (2EHA/AA) strongly interacted with the amide LC, with the tertiary amine AMP, and with the carboxylic acid KP; PSA-containing acrylamide (2EHA/AAm), however, did not interact with LC or AMP, although it markedly interacted with KP. The rubber-type and silicone-type PSAs, composed of no or only a few polar functional groups, did not interact with any of the drugs used in this experiment. Therefore, the diffusion coefficient of the drugs through PSA was influenced by the drug-PSA polymer interaction, and the extent of this interaction can be estimated by the relationship between the drug concentrations in the PSA and their diffusion coefficients.

Cyclopentadienyl-, Indenyl- und Trifluormethylcyclopentadienyl-Cobalt-Komplexe mit Akzeptor-substituierten Olefinen als Liganden / Cyclopentadienyl, Indenyl and Trifluoromethylcyclopentadienyl Cobalt Complexes with Acceptor-Substituted Olefins as Ligands

The complexes C5H5Co(PMe3)2 (1), C9H7Co(PMe3)2 (2) and (C5H4CF3)Co(PMe3)2 (3) react with mono- and disubstituted ethenes such as styrene, acrylic acid methylester, methylvinylketone, acroleine, acrylic acid amide, acrylonitrile, maleic anhydride, maleic and fumaric acid dimethylester, and fumaric dinitrile to give the olefin(phosphane)cobalt compounds (ring)Co(PMe3)(olefin) (4-32) in good to excellent yields. With acrylonitrile, two different rotamers are obtained which indicates that there is a considerable energy barrier for rotation around the metal-olefin bond. The reactions of 1 and 3 with maleic acid dimethylester (MDE) lead not only to the formation of the expected products (ring)Co(PMe3)(MDE) (22, 23) but also to the thermodynamically favored isomers (ring)Co(PMe3)(FDE) (24, 26) containing fumaric acid dimethylester (FDE) as ligand. A similar isomerization has been observed upon treatment of 2 and 3 with fumaric dinitrile (FDN) which gives besides the complexes (ring)Co(PMe3)(FDN) (29, 31) also the maleic dinitrile (MDN) derivatives (ring)Co(PMe3)(MDN) (30, 32). The olefin(trimethylphosphane)cobalt compounds are surprisingly inert and neither on photolysis nor on heating give the isomeric hydrido(vinyl)metal complexes.

Deformation of polyelectrolyte gels under the influence of electric field

AbstractDeformation of acrylic acid–acrylamide copolymer gels in an aqueous solution under the influence of a dc electric field was studied. In the electric field, the gel swells, shrinks, or bends. It depends on the concentration of polyion coo− in the gel. When the concentration is low, the gel shrinks, and, when high, it swells. The gel which does not contain polyion is not influenced by the electric field. The long and thin gel is bent in an arc. The bent gel can be recovered to the original shape by removing the applied electric field or by changing the polarity of the applied electric field. The deformation is closely related to two substantial changes. One is the change of the osmotic pressure caused by the ion concentration difference between the inside and the outside of a gel. The other is the conformational change of the polymer network with decreasing of the polyion concentration.

Synthesis of Layered Polysilicic Acid–Acrylamide Intercalation Compounds and Polymerization in the Interlayer Spaces

Abstract Layered polysilicic acid–acrylamide intercalation compounds were synthesized by the reaction of H-magadiite (H2Si14O29·xH2O) and H-kenyaite (H2Si20O41·xH2O) with acrylamide saturated aqueous solutions. The formation of the intercalation compounds were ascertained by X-ray powder diffraction, IR, 13C-CP MAS NMR, DTA, and chemical analysis. However, when H-magadiite was used, a part of the intercalated acrylamide molecules was oligomerized during the intercalation. A heat treatment of the layered polysilicic acid–acrylamide intercalation compounds led to a polymerization of the acrylamide in the interlayer spaces.

A new coupling agent for aramid fibers

Various compounds were used for the surface treatment of aramid fibers in order to promote adhesion to polymeric matrices. The improvement of adhesive bond could be based either on the roughness of fiber surface or on chemical modification introduced by grafting. The compounds used are more or less reactive to the secondary amide groups, present on the aramid chain. Thus, the fibers were impregnated with acetic acid anhydride, sulfuric acid–acrylamide, and methacryloyl chloride. The effect of such treatment was first evaluated by optical microscopy and infrared analysis. Tensile measurements were also carried out in order to define any changes of strength and modulus. Finally, tensile specimens were prepared using unsaturated polyester reinforced with aramid fibers and the effect of chemical treatment on the tensile strength was determined. From the above study, methacryloyl chloride was proved an effective coupling agent with possible grafting to aramid fibers.

A method for the calculation of compositions of radical‐chain copolymerizations

AbstractIn this article the straight‐line relationship between In A and B, where A and B denote the concentrations of the two types of monomers in any reaction period, is examined to exist in the radical copolymerizations of 1.02 ≥ r1r2 ≥ 0.25. Utilizing this observation, we propose an easy‐to‐use compositions calculation method in which a single empirical parameter is included. The method is derived without involving the constant monomer reactivity ratios assumption. The copolymerizations of styrene–methyl methacrylate vinyl chloride–vinyl acetate, methyl methacrylate–vinyl acetate, acrylic acid–acrylamide, methacrylic acid–methacrylamide, and sodium methacrylate–methacrylamide are investigated. The instantaneous and cumulative copolymer compositions and the residued monomer compositions computed by this proposal are in very good agreement with the experimental data.

Interactions between aluminium ions and acrylic acid—acrylamide copolymers in aqueous solution: 1. Study by 27Al nuclear magnetic resonance

Aluminium binding to acrylic acid-acrylamide copolymers at different pH values has been studied by 27Al n.m.r. at 104.2 MHz. The study of a pure AlCl 3 solution of 1 × 10 −3 moll −1 concentration (at 25°C) allowed us, using a computer calculation, to define the concentration of different presumed Al species during the Al 3+ hydrolysis, when the OH − Al varied from 0 to 3. A model is proposed which takes into account the electrostatic interaction between trivalent Al species (Al 3+ and Al 13(OH) 3+ 27) and the carboxylate groups of the copolymers. The amount of Al cations bound to the copolymers was then calculated as a function of the pH.

Study of copolymer–copolymer interactions and formation of intermacromolecular complexes

AbstractInterpolymer complex formation has been studied between methacrylic acid‐methacrylamide copolymer and acrylic acid–acrylamide copolymer. The respective co‐monomer units of the two copolymers enter into complex formation through H‐bonding and ion dipole interactions. The unreacted units in the copolymer complex also interact with homopolymers such as PEO and PVP to form ternary complex. Formation of complexes and replacement reactions could be shown through several experimental techniques, e.g., viscometry, conductometry, and potentiometry.

Identification of histone H2b as a heat-shock protein in Drosophila.

Total cell polypeptides synthesized, in cultured Drosophila cells under control (25 degrees C) and heat-shock (37 degrees C) conditions have been compared in two different two-dimensional polyacrylamide gel electrophoresis systems which, together, resolve polypeptides having a wide range of isoelectric points, including the most basic polypeptides of the cell. The electrophoresis of basic proteins showed that the most prominent basic polypeptide synthesized in heat shock comigrated with histone H2b. This heat-shock polypeptide was identified as histone H2b by two criteria: (a) it comigrated with authentic histone H2b in Triton-urea-acetic acid acrylamide gel electrophoresis after solubilization from nuclei with acid; and (b) partial proteolysis peptide maps of the basic heat-shock protein and histone H2b were identical. The synthesis of histone H2b was induced threefold in heat shock, whereas synthesis of the other histones was reduced from two- to tenfold. The noncoordinate synthesis of histones in Drosophila in heat shock provides an interesting system in which to investigate transcriptional and translational controls of histone synthesis as well as assembly of histones into chromatin.

Preparation and Reactions of Some Derivatives of Acrylic Acid Hydrazides and Amides

Preparation and Reactions of Some Derivatives of Acrylic Acid Hydrazides and Amides