Showing papers on "Acrylamide published in 1999"

Role of cytochrome P450 2E1 in the metabolism of acrylamide and acrylonitrile in mice.

Abstract: Acrylonitrile (AN) and acrylamide (AM) are commonly used in the synthesis of plastics and polymers. In rodents, AM and AN are metabolized to the epoxides glycidamide and cyanoethylene oxide, respectively. The aim of this study was to determine the role of cytochrome P450 in the metabolism of AM and AN in vivo. Wild-type (WT) mice, WT mice pretreated with aminobenzotriazole (ABT, 50 mg/kg ip, 2 h pre-exposure), and mice devoid of cytochrome P450 2E1 (P450 2E1-null) were treated with 50 mg/kg [13C]AM po. WT mice and P450 2E1-null mice were treated with 2.5 or 10 mg/kg [13C]AN po. Urine was collected for 24 h, and metabolites were characterized using 13C NMR. WT mice excreted metabolites derived from the epoxides and from direct GSH conjugation with AM or AN. Only metabolites derived from direct GSH conjugation with AM or AN were observed in the urine from ABT-pretreated WT mice and P450 2E1-null mice. On the basis of evaluation of urinary metabolites at these doses, these data suggest that P450 2E1 is possi...

Immobilization of acrylamide-modified oligonucleotides by co-polymerization

Abstract: A flexible chemistry for solid phase attachment of oligonucleotides is described. Oligonucleotides bearing 5'-terminal acrylamide modifications efficiently co-polymerize with acrylamide monomers to form thermally stable DNA-containing polyacrylamide co-polymers. Co-polymerization attachment is specific for the terminal acrylamide group. Stable probe-containing layers are easily fabricated on supports bearing exposed acrylic groups, including plastic microtiter plates and silanized glass. Attachment can be accomplished using standard polyacrylamide gel recipes and polymerization techniques. Supports having a high surface density of hybridizable oligonucleotide (approximately 200 fmol/mm2) can be produced.

Determination of Acrylamide Monomer in Polyacrylamide Degradation Studies by High-Performance Liquid Chromatography

Abstract: A high-performance liquid chromatography method using C18 and ion-exchange columns in series is developed for the determination of acrylamide and acrylic acid monomers in polymeric samples. The C 18 column acts as a guard column, trapping surfactants and impurities and retaining the nonionic species. The ion-exchange column then separates the monomers according to their respective ionic strengths. This method has been proven in the laboratory to work successfully for all types of acrylamide/acrylic acid polymers and matrices. Detection limits for both monomers can be achieved in the parts-per-billion range. The method is used to study the possible degradation of polyacrylamide to acrylamide monomer in the presence of glyphosate (a herbicide) and sunlight. Polyacrylamide is used as a spray drift reduction aid in combination with glyphosate. In normal applications, the polymer and herbicide are in contact with each other in the presence of sunlight. The results show that the polymer does not degrade to acrylamide in the presence of glyphosate or sunlight or any combination of the two. It is also observed that glyphosate influences the solubility of polyacrylamide, and care must be used when combining the two.

Fungal laccase grafts acrylamide onto lignin in presence of peroxides

Abstract: Laccase (EC 1.10.3.2) from the white-rot basidomycete Trametes versicolor in the presence of organic peroxides, particularly dioxane peroxide, tetrahydrofuran peroxide and t-butylhydroperoxide, initiated free-radical copolymerization of acrylamide and lignin. Hydrogen peroxide showed no such effect. Both the type of peroxide and the catalytic efficiency of the enzyme were important to ensure a significant yield of copolymerisate and a high rate of acrylamide incorporation into a lignin backbone. The mechanism of the enzymatic grafting is discussed.

Sodium dodecyl sulfate capillary electrophoresis of wheat proteins. 1. Uncoated capillaries.

Abstract: Four different polymer/buffer systems (a commercial polymer from Bio-Rad, dextran, poly(ethylene oxide) (PEO), and non-crosslinked poly(acrylamide)) were evaluated for use in sodium dodecyl sulfate capillary electrophoresis (SDS-CE) separations of wheat proteins. These polymers were chosen on the basis of published reports of their use in uncoated or dynamically coated capillaries. Each polymer was optimized (where possible) by manipulating the polymer concentration and buffer concentration, and through the use of organic modifiers such as methanol and ethylene glycol. The addition of ethylene glycol to the separation buffer was found to improve the resolution of the separations, despite dilution of the sieving polymers. When PEO was used as the sieving polymer, however, no improvement was seen when ethylene glycol was added. Despite producing similar separations of molecular mass markers, the polymers did not all produce similar wheat protein separations. The commercial reagent and dextran produced similar separations, while the poly(acrylamide) produced faster separations than either. The poly(acrylamide) displayed much lower resolution in the 40-60 kDa range than the other polymers, though this polymer was able to separate the high molecular mass glutenin subunits (HMM-GS) without the use of added organic solvent. PEO produced much different wheat protein separations than the other polymers, despite similar separations of the molecular weight markers. This may have been due to interaction between the wheat proteins and PEO. Each polymer system also predicted different molecular masses of the various wheat protein fractions separated, with the PEO and poly(acrylamide) grossly overestimating the masses for all protein classes. This could have been due to protein-polymer interactions. Further work was done with the Bio-Rad buffer modified by the addition of ethylene glycol. Several different wheat protein fractions as well as proteins extracted from several different cultivars were separated with this buffer and compared. SDS-CE separations were also compared to SDS-poly(acrylamide) gel electrophoresis (PAGE) and several differences in the migration pattern of HMM-GS were noted.

A kinetic approach to acrylamide radical polymerization by horse radish peroxidase‐mediated initiation

Abstract: Free-radical polymerization of acrylamide in water at room temperature involves catalysis by horse radish peroxidase to produce radical species from hydrogen peroxide and 2,4-pentanedione through an oxidoreductive pathway. In the presence of the vinylic monomer, initiation takes place, leading to polyacrylamide formation after a long and unreproducible inhibition period. Conversion-time plots are presented, and some kinetic features are compared with results of previous studies of classical acrylamide polymerization.

Self-condensing vinyl polymerization of acrylamide

Abstract: A novel approach to branched polyacrylamide was described. The branched structure resulted from the amidyl radicals which were formed by the reaction of amide groups with Cu(III) of potassium diperiodatocuprate, K5[Cu(HIO6)2], in alkaline medium and capable of initiating the vinyl polymerization of acrylamide monomer. The obtained polymer was characterized by 1H NMR, FT-IR and intrinsic viscosity measurements.

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry for monitoring alkylation of beta-lactoglobulin B exposed to a series of N-substituted acrylamide monomers.

Abstract: Delayed-extraction matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry, in both linear and reflectron modes, has been used to examine the alkylation of bovine beta-lactoglobulin-bound cysteines exposed to various molar concentrations (0.5-30 mM) of acrylamide and a number of its N-substituted monomers. These measurements were conducted at pH approximately 9.5, and showed that at 0.5 mM all monomers (except N-acryloylaminopropanol) resulted in a measurable alkylation of at least one cysteine out of five. At higher concentrations (15 mM) all investigated monomers resulted in substantial alkylation which, for some, involved all five cysteine residues. Reflectron MALDI-TOF measurements of a number of alkylated protein digests revealed that, at low molar ratios, the alkylation site is influenced by the identity of the monomer. For example acrylamide and N, N-dimethylacrylamide attacked Cys(160) as well as one of the three cysteines within the tryptic fragment [102-124], while other investigated monomers did not involve Cys(160). The implications of the present data for two-dimensional (2D) gel electrophoresis, and their eventual correlation to the toxicity of the investigated monomers, are discussed.

The grafting of acrylamide onto poly(?-caprolactone) and poly(1,5-dioxepan-2-one) using electron beam preirradiation. I. Influence of dose and Mohr's salt for the grafting onto poly(?-caprolactone)

Abstract: Poly(e-caprolactone) films (TONE® 787) were irradiated by electron beam in air prior to grafting in aqueous solutions of acrylamide. The grafting kinetics and molecular weight of the grafted poly(acrylamide) chains were studied with irradiation doses between 2.5 and 20 Mrad and in the Mohr's salt concentration range of 0.0025-1 wt %. The grafting rate and yield were strongly dependent on the Mohr's salt concentration. By molecular weight analysis of grafted poly(acrylamide) chains, it was shown that the molecular weight is approximately proportional to the mass of the grafted PAAm.

Gamma‐radiation‐induced graft copolymerization of acrylamide onto crosslinked poly(N‐vinylpyrrolidone)

Abstract: Crosslinked poly(N-vinylpyrrolidone) (PVPy) beads were irradiated with y-rays in air from a 60 Co source. Preirradiated beads were grafted with polyacrylamide by refluxing with acrylamide in water or dioxane. Conditions for optimum grafting were determined under a variety of reaction parameters, such as the total dose, duration, and temperature of heating, and the molar concentration of acrylamide used. The effect of the addition of methanol to the aqueous medium during grafting was also studied. The pendant carboxamide groups of PVPy-g-polyacrylamide were transformed into amino, aminoethylamido, and hydrazide functionalities terminating in primary amino or hydrazido groups. These provide sites for immobilizing proteins through their amino or carboxyl groups and, also, handles for attaching reagent molecules.

Swelling of hydrophobically modified poly(acrylamide) and poly(acrylamide)-co-(acrylic acid) gels in surfactant solutions

Abstract: A series of hydrophobically modified polyacrylamide and polyacrylamide-co-poly(acrylic acid) gels with systematically varying hydrophobicity were prepared by free-radical polymerization of acrylamide, n-alkylacrylamides (n = 10, 12, and 14), and acrylic acid. The swelling of these gels was examined in water and in both anionic and cationic surfactant solutions. It was found that the gels which incorporated acrylic acid showed extremely high swelling in water. Maximum swelling was observed in gels which incorporated 10 mol% acrylic acid. The swelling of these gels was much less in solutions of both anionic and cationic surfactants than in water. The gels which did not incorporate acrylic acid demonstrated little swelling in water, but showed increased swelling in both anionic and cationic surfactant solutions with increased hydrophobicity of the gel.

Volume phase transition behavior of N‐isopropyl acrylamide–N‐cyanomethyl acrylamide copolymer gel particles: The effect of crosslinking density

Abstract: We prepared submicron-sized N-isopropyl acrylamide (NIPA)–N-cyanomethyl acrylamide (NCMA) copolymer gel particles by precipitation polymerization. Volume phase transition behaviors of gel particles with various compositions and crosslinking density were observed by using photon correlation spectroscopy (PCS). The experimental data showed that both the volume transition temperature and the swelling ratio of copolymer gel particles were varied with the mole ratio of NCMA and NIPA. We compared the swelling behaviors of given systems with the thermodynamic model based on the extended Flory–Huggins theory. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1091–1099, 1999

Process for the inhibition of scale in harsh systems and novel antiscalants for same

Abstract: Improved process for inhibiting calcium carbonate scaling in aqueous systems such as that employed in the Kraft pulping process. Such an improved process is achieved by the addition of at least one antiscalant comprising one monomer unit derived from the group consisting of 1,2-dihydroxy-3-butene, N-(hydroxymethyl)acrylamide and N-(sulfoxymethyl)acrylamide, and at least one monomer unit derived from the group consisting of maleic acid, acrylic acid, acrylamide, methacrylic acid, itaconic acid, vinyl sulfonic acid, styrene sulfonic acid, N-tertbutylacrylamide, butoxymethylacrylamide, N,N-dimethylacrylamide, sodium acrylamidomethyl propane sulfonic acid, and salts thereof.

Paper surface improver

Abstract: PROBLEM TO BE SOLVED: To obtain a surface coating agent comprising an aqueous solution of a high-molecular but lowly viscous acrylamide polymer SOLUTION: This improver comprises an aqueous solution of an acrylamide polymer obtained by subjecting an aqueous solution of a mixture comprising at least 40 mol% acrylamide, 01-30 mol% anionic monomer, and 005-10 mol% methacrylonitrile to a polymerization reaction It is desirable that the aqueous solution of the mixture further contains at least one member selected from among a vinyl cyanide compound, a crosslinking agent, and a chain transfer agent in an amount of 01-45 mol% based on the entire weight of the monomers constituting the acrylamide polymer when the mixture contains the vinyl cyanide compound, 0005-3 mol% based on the entire weight of the monomers when it contains the crosslinking agent, or 001-8 mol% based on the entire weight of the monomers when it contains the chain transfer agent

Detection of protease activities using specific aminoacyl or peptidyl p-nitroanilides after sodium dodecyl sulfate - polyacrylamide gel electrophoresis and its applications.

Abstract: A general method for detecting protease activities on acrylamide or agarose gels after sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) using specific aminoacyl p-nitroanilide (NA) or peptidyl NA as substrate is described This method is extended from the spectrophotometric assay of p-nitroaniline, which is a chromogenic product liberated by protease action on aminoacyl NA or peptidyl NA The acrylamide gel containing protein bands was dipped directly into a solution which contained specific synthetic aminoacyl NA or peptidyl NA as a substrate or had been overlaid with an agarose gel containing the same substrate The p-nitroaniline released on the acrylamide or agarose gel by the specific protease was diazotized with sodium nitrite and then coupled to N-(1-naphthyl)-ethylenediamine to produce distinct activity band(s) The substrates used for protease activity staining on gels were identical to those used for spectrophotometric assays Some applications are described

Method of preparing gel-like material for plastics of soft tissues

Abstract: FIELD: medicinal polymers. SUBSTANCE: gel-like material containing 1.0- 8.0 wt % of acrylamide/methylene-bis-acrylamide copolymer (from 100:0.5 to 100:5.0) and 92.0-99.0 wt % of weakly alkaline water with pH 6.9- 8.5, level of permanganate oxidability up to 1 mgO/l and level of bromination capacity not higher than 3.0 mgBr/l is prepared by copolymerization of acrylamide with methylene-bis-acrylamide in aqueous medium at pH 9.0-9.5 in presence of peroxide polymerization initiator. Reaction mixture is incubated for 2 to 24 hr at 20 to 90 C and then 2-4 hr at 100-105 C. Upon implantation of this material, there is lack of marked inflammatory response and, in later phases, sclerotic phenomena and intergrowth of implant are not observed, while homogeneous structure is preserved. EFFECT: improved biological compatibility. 3 cl, 1 dwg

Synthesis, characterization and associative properties of triblock and diblock perfluorinated poly(acrylamide)s

Abstract: A triblock perfluorinated poly(acrylamide) was produced by polymerization of acrylamide at 82 °C in acetonitrile using a difunctional azo-derivative initiator bearing fluorinated groups. The presence of triblock structures was revealed by GPC analyses by changing the nature of the solvent. Fractionation of a poly(acrylamide) sample allowed us to isolate the triblock fractions from the diblock ones. Polymerization with a small amount of initiator led to a sample with few triblock structures compared to a polymerization with a large amount of initiator. It can be concluded from this that acrylamide rather gives disproportionation according to the literature and that triblock formation comes from primary radical termination.

Production of acrylamide-based polymer dispersion

Abstract: PROBLEM TO BE SOLVED: To provide a method for producing a highly concentrated acrylamide- based polymer dispersion having good fluidity and capable of being readily treated at a low cost by polymerizing a water-soluble monomer including an acrylamide-based monomer in an aqueous solution of an inorganic salt in the presence of a polymer consisting essentially of vinylpyrrolidone and a glycol derivative. SOLUTION: (A) A water-soluble monomer including an acrylamide-based monomer (e.g. sodium acrylate) is polymerized in an aqueous solution of (B) an inorganic salt (e.g. ammonium sulfate and sodium sulfate) in the presence of (C) a polymer consisting essentially of vinylpyrrolidine (e.g. polyvinylpyrrolidone, a copolymer of the vinylpyrrolidone and vinyl acetate) and (D) a glycol derivative (e.g. propylene glycol monomethyl ether) in the method for producing a highly concentrated acrylamide-based polymer dispersion. The component A in an amount of 1-40 wt.% based on the whole weight of the reaction liquid is preferably included. The component C in an amount of 0.1-100 pts.wt. and the component D in an amount of 0.01-10 pts.wt. based on 100 pts.wt. component A are preferably used.

Peptide Maps of Porcine Pepsin Prepared Using Soluble and Immobilized α-Chymotrypsin

Abstract: Reverse-phase high performance liquid chromatography (RP-HPLC) was used for characterization of peptide maps of porcine pepsin using soluble or immobilized α-chymotrypsin. The immobilized enzyme was prepared by its coupling to periodate-oxidized poly(acrylamide- co -allyl α-D-galactoside or allyl β-lactoside) copolymer ( O -glycosylated acrylamide copolymer). After sodium cyanoborohydride reduction, a stable linkage was formed. Specific activity of α-chymotrypsin, linked to the copolymer containing bound α-D-galactosyl or β-lactosyl residues was 59.1 or 314.4% activity of soluble enzyme.

The chemistry and properties of poly(acrylamide-acrylic acid) resins

Abstract: Acrylamide polymeric resins such as: poly(acrylamide-acrylic) acid p(AM-AA), poly (acrylamide-acrylic acid-diallylamine hydrochloride p(AM-AA-DAA)+Cl−] and poly(acrylamide-acrylic acid-diallylethylamine hydrochloride) p[(AM-AA-DAEA)+Cl−] were prepared by gamma radiation-initiated template polymerization of acrylic acid on acrylamide polymers. Copolymerization of acrylic acid with acrylonitrile produce poly(acrylic acid-acrylonitrile) p(AA-AN) resin. The capacities of the prepared polymeric materials were investigated at different doses. The results showed that the maximum experimental capacities are similar to their theoretical values. The chemical stability of the polymeric materials were investigated at different pH-values. The mechanism of interaction between the functional groups of the polymeric chains and ions in aqueous solution were studied. The polymeric materials have extraordinary capacities and were used as good exchangers in the treatment of wastewater for removal of metallic ions from their ...

Purification of aqueous solution of acrylamide and production of acrylamide polymer

Abstract: PROBLEM TO BE SOLVED: To provide a process for purifying an aqueous solution of acrylamide in high quality with easy operation compared with conventional process. SOLUTION: An aqueous solution of acrylamide produced by the hydration of acrylonitrile in the presence of a copper catalyst is subjected to copper- removal treatment and maintained at 5-40 deg.C and pH 10-12. An acrylamide polymer is produced by homopolymerization or copolymerization of the aqueous solution of acrylamide produced by the purification process. The aqueous solution of acrylamide produced by the process gives a high-molecular acrylamide polymer having a molecular weight of especially about 15,000,000-20,000,000 and having high performance such as water-solubility.

Synthesis of n-monoalkyl(meth)acrylamide

Abstract: PROBLEM TO BE SOLVED: To inexpensively and stably obtain the subject high-purity compound by using industrially inexpensively available cyclohexylamine as a protective agent for the double bond of a (meth)acrylic ester. SOLUTION: This compound, an N-monoalkyl(meth)acrylamide, is obtained using an amino amide of formula I (R1 is H or CH3; R2 is CnH2n+1; n is a natural number of 1-4) as intermediate. The amide adduct of formula I, in turn, is prepared by synthesizing a Michael adduct of a (meth)acrylic ester of formula II (R3 is CmH2m+1; m is a natural number of 1-4) and cyclohexylamine followed by reaction of the Michael adduct with a monoalkylamine in the presence of a strongly basic catalyst; the amino adduct thus obtained is thermally decomposed to form the objective N-monoalkyl(meth)acrylamide, which can be purified by distillation; thereby the objective compound can be afforded in an industrially advantageous way, such as without substantially producing dimeric adduct.