Showing papers on "Methyl isobutyl ketone published in 1995"

Behavior of biofilters for waste air biotreatment. 1. Dynamic model development.

Abstract: An novel diffusion reaction model for the determination of both the steady-state and transient-state behavior of biofilters for waste air biotreatment is developed and discussed. The model considers the reactor to comprise finite sections, for each of which transient mass balances are established and solved by digital simulation. The elimination of methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) vapors from air as single and mixed pollutants serves as an example to illustrate and discuss both the model's response and its parametric sensitivity. Experimental evaluation of the model is presented in part 2 of this paper.

Behavior of biofilters for waste air biotreatment. 2. Experimental evaluation of a dynamic model.

Abstract: Experimental evaluation of a diffusion reaction model (part 1) for the determination of both steady- and transient-state behavior of biofilters for waste air biotreatment is presented. The model, applied to the aerobic biodegradation of methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) vapors from air as single and as mixed pollutants, proved appropriate for describing most of the experiments undertaken and served as a basis for comprehensive understanding of biofilter operation.

Preconcentration of Copper Traces on C60-C70 Fullerenes by Formation of Ion Pairs and Chelates

Abstract: The adsorptive potential of C{sub 60} and C{sub 70} fullerenes for the preconcentration of copper traces was assessed for the first time in this work. The method used for this purpose involves the formation, adsorption on a fullerene mini-column, and elution with 250 {mu}L of methyl isobutyl ketone of various ion pairs or chelates of copper. A sample loading time of 2 min provides an enrichment factor for copper between 40 and 185 relative to direct introduction of aqueous solutions into an atomic absorption spectrometer. The effect of concurrent cations was investigated in order to optimize the best chemical system (ion pairs or chelate) for the determination of copper. The systematic study carried out in this work allows us to conclude that the best selectivity and sensitivity are achieved with chelate formation and sorption on C{sub 70} fullerene. 20 refs., 3 figs., 3 tabs.

Thermodynamic and kinetic parameters of lipase‐catalyzed ester hydrolysis in biphasic systems with varying organic solvents

Abstract: Kinetics of lipase-catalyzed hydrolysis of esters were modeled using reactant activities for aqueous-organic, biphasic systems. By using thermodynamic activities of the substrates in ordinary rate equations, the kinetic parameters were corrected for the contribution of substrate-solvent interactions and a uniform quantification of the substrates for lipase attached to the interface can be achieved. The kinetic parameters, on the basis of their thermodynamic activities, should be constant in different systems, provided that the solvents do not interfere with the binding of the substrates to the enzyme nor affect the catalytic mechanism. Experimental and computational methods on how to obtain the thermodynamic activities of the substrates are presented. Initial rates were determined for Pseudomonas cepacia lipase (PcL)-catalyzed hydrolysis of decyl chloroacetate in dynamic emulsions with various solvents. The thermodynamic equilibrium and corrected kinetic constants for this reaction appeared to be similar in various systems. The kinetics of PcL in an isooctane-aqueous biphasic system could be adequately described with the rate equation for a ping-pong mechanism. The observed inhibitory effect of decanol appeared to be a consequence of this mechanism, allowing the backreaction of the decanol with the chloroacetyl-enzyme complex. The kinetic performance of PcL in systems with toluene, dibutyl ether, and methyl isobutyl ketone could be less well described. The possible causes for this and for the remaining differences in corrected kinetic parameters are discussed.

Evaluation of Exposure to Solvents from Their Urinary Excretions in Workers Coexposed to Toluene, Xylene, and Methyl Isobutyl Ketone

Abstract: To evaluate the intensity of worker exposures to mixed solvents, the concentrations of hippuric acid (HA), methylhippuric acids (MHAs), and methyl isobutyl ketone in end-of-shift urine were examine...

Ketone potentiation of haloalkane-induced hepato- and nephrotoxicity. II. Implication of monooxygenases.

Abstract: Previous results in Sprague‐Dawley rats indicate that acetone (A), methyl ethyl ketone (MEK), and methyl isobutyl ketone (MiBK) pretreatment (3 d, po) at dosages of 6.8 and 13.6 mmol/kg potentiate CCl4 hepatotoxicity and CHCl3 nephrotoxicity, respectively. The potentiation potency profile observed was MiBK > A > MEK for liver and A > MEK ≥ MiBK for kidney toxicity (Raymond & Plaa, 1995). In the present study, hepatic and renal microsomes from A‐, MEK‐, and MiBK‐pretreated rats (6.8 or 13.6 mmol/kg) were examined for cytochrome P‐450 content, substrate‐specific monooxygenase activity (aminopyrine and benzphetamine N‐demethylase, aniline hydroxylase) and in vitro covalent binding of 14CHCl3 and 14CCl4. Of the three ketones, only MiBK significantly increased P‐450 content of liver and renal cortical microsomes. Similarly, 14CCl4 covalent binding under aerobic and anaerobic conditions was significantly increased by MiBK pretreatment only. 14CHCl3 covalent binding by renal cortical microsomes was significantly...

Micelle formation and polyisobutylene solubilization by polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene block copolymers

Abstract: Thermodynamics of micellization and the structure of micelles formed by polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene block copolymers were studied. A molar mass influence on the aggregation number of micelles was found. The lower the molar mass, the higher the micelle aggregation number. The solubilization of polyisobutylene by micelles of these copolymers in methyl isobutyl ketone was also examined. The saturation concentrations of polyisobutylene solubilized by different block copolymers in methyl isobutyl ketone were determined by laser light scattering. The solubility curves found were linear and dependent on the molar mass of the polyisobutylene solubilized and the copolymer. The logarithm of the maximum amount of polyisobutylene solubilized by mass unity of the triblock copolymer varies linearly with the logarithm of the molar mass of the polyisobutylene. This variation is hardly dependent on the copolymer molar mass and strongly dependent on the type of block copolymer.

Molecular Interaction in a Polar-Polar System-Methyl Isobutyl Ketone (MIBK) and Primary Aliphatic Alcohols– Using Dielectric Measurements

Abstract: Dielectric constant of binary mixtures of Methyl isobutyl Ketone (MIBK) with a number of aliphatic alcohols, namely 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol has been measured at 303.16 K and 455 kHz. The data are used to compute the mutual correlation parameter g ab , excess molar polarization Δ P , and excess Gibb's free energy Δ G in those mixtures with a view to assessing the suitability of the alcohol as a modifier. The trend of variation of g ab indicates that octanol could be grouped with other higher alcohols already used as modifier.

Analysis of Fe, Cu, Ni and Co in fluoride glasses and their precursors

Abstract: A method for the determination of iron, copper, nickel and cobalt in zirconium fluoride and heavy metal fluoride glasses is presented. This method involves dissolution in a boric acid solution, complexation of transition metal ions with sodium diethyl dithiocarbamate and ammonium pyrrolidine dithiocarbamate at pH 2.2, extraction of the complexes with methyl isobutyl ketone, back extraction with Hg (II) solution and graphite furnace atomic absorption spectroscopy analysis. This method is applicable for determination of Fe, Cu, Ni and Co at concentrations

Rubberized paint coating process

Abstract: A process for applying a rubberized paint coating to a plastic surface uses a diluent to dilute rubberized paint having a composition of comparatively larger fractions of xylene and cyclohexanone and comparatively smaller fractions of methyl isobutyl ketone (MIBK) and butylcellusolve. The preferred diluent composition is 6.4% methyl isobutyl ketone, 39.1% xylene, 13.4% butylcellosolve, and 41.1% cyclohexanone. A small amount of hardener may also be added for improved results. Drying for about 10 minutes at 35° C. is found to obtain a good rubber finish without degradation of the plastic surface. A wrapping of tissue paper for packaging the rubberized paint coated article is found to avoid dissolving, chipping, scratching, or adhering to the coated surface.

Speed of sound and isentropic compressibilities of N,N-diemthylformamide+methyl isobutyl ketone+1-alcohols at 303.15 K

Abstract: Speed of sound and densities were measured for N,N-dimethylformamide + methyl isobutyl ketone + 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol at 303.15 K. Isentropic compressibilities and excess isentropic compressibilities from ideality were computed. Excess isentropic compressibility values are negative throughout the range of volume fraction in all four ternary mixtures.

Plasma display panel barrier forming application liquid, its manufacture, and barrier forming method

Abstract: PURPOSE: To form a defect-free barrier forming layer in one run of operation by preparing a coating liquid for formation of PDP barrier from a glass powder having a low melting point, fire-resistant filler, binder resin, and solvent, wherein the boiling point of the solvent should be below 150°C at a normal pressure. CONSTITUTION: A small quantity of solvent having high boiling point such as di. 2-ethylhexylpthalate is added to a solvent having a low boiling point such as methyl isobutyl ketone, in which a binder resin such as ethyl cellulose is dissolved, and thereto a plasticizer such as polyoxyethylene alkyl phosphate (ester) is added so that a vehicle is produced. and to this vehicle, glass frit, crushed brown alumina, and black pigment are added in despersion so that a coating liquid is provided. An electrode 2 and a dielectric substance layer 3 are formed on a glass board 1 on the back surface of a plasma display panel(PDP), and the coating liquid is cast to form a barrier forming layer 4. Thereover a resist pattern 7 is formed. followed by sandblasting and baking, and a defect-free barrier 8 in good shape is obtained. COPYRIGHT: (C)1996,JPO

Production of low-molecular brominated epoxy polymer

Abstract: PURPOSE:To produce a low-molecular brominated epoxy polymer capable of providing a resin excellent in flame retardancy, mechanical strength and heat resistance while reducing formation of a by-product by reacting brominated bisphenol A with epichlorohydrin under a specified condition. CONSTITUTION:Brominated bisphenol A is reacted with excessive epichlorohydrin in the presence of an alkali metal hydroxide as a catalyst and the remaining epichlorohydrin is subsequently removed from the reaction system. The reaction product is then subjected to dehydrochlorination in the presence of an alkali metal hydroxide in an organic solvent such as methyl isobutyl ketone, thus producing the objective low-molecular brominated epoxy polymer.

Determination of silver in sulfide minerals by ETAAS

Abstract: A method for the determination of silver in sulfide minerals (realgar, orpiment, lorandite, marcasite, and stibnite) as well as dolomite by electrothermal atomic absorption spectrometry is discussed. After dissolution of the samples, silver was extracted by diphenyl thiocarbamate in hydrochloric acid media using methyl isobutyl ketone, butyl acetate, or toluene as the solvent. The procedure was verified by the method of standard additions and with standard reference samples. The standard deviation (SD) for 0.5 ng/Ag was 0.01 ng. The relative standard deviation ranged from 3-5%. The detection limit, calculated as three SDs of the blank, was found to be 0.001 μg/g.

Synergistic extraction behavior of samarium(III), europium(III) and dysprosium(III) with 1-nitroso-2-naphthol and 1,10-phenanthroline

Abstract: The equilibrium extraction behavior of Sm(III), Eu(III) and Dy(III) from aqueous NaClO4 solutions in the pH range of 4–9 at 0.1 M ionic strength into organic solutions of 1-nitroso-2-naphthol (HA) and 1,10-phenanthroline (Phen) has been studied. The equilibrium concentrations of Eu were assayed through the 344 keV photopeak of the152Eu radiotracer used. The concentrations of Sm and Dy were measured by irradiating one mL portions of the organic extract and analyzing the 104 and 108 keV photopeaks of the short-lived neutron activation products,155Sm and165mDy, respectively. Quantitative extraction of Eu with 5×10−2 M HA alone was obtained in the pH range of 6.7–7.8 with n-butanol, 7.4–8.5 with chloroform, 8.0–8.7 with ethyl acetate, 7.7–8.5 with isoamyl alcohol and 6.1–8.0 with methyl isobutyl ketone (MIBK). But, Eu was extracted only to a maximum of 78% and 83% in the pH range of 8.3–8.9 and 7.4–8.1 with carbon tetrachloride and xylene, respectively. The extraction of Sm and Dy were found quantitative in the pH range of 6.3–7.0 and 6.6–7.1, respectively, with 5×10−2 M HA alone in MIBK solutions. The synergistic extraction of Eu was quantitative in the pH range of 6.6–9.8 with chloroform, 7.8–8.9 with ethyl acetate, 7.7–8.5 with isoamyl alcohol and 6.0–9.6 with MIBK when 1×10−2 M each of HA and Phen were employed. Sm and Dy were quantitatively extracted into MIBK solutions containing 5×10−2 M each of HA and Phen in the pH range 6.0–7.5 and 6.1–7.5, respectively. The distribution ratios of these lanthanides (Ln) were determined as a function of pH, and HA and Phen concentrations. The analysis of the data suggests that these Ln are extracted as LnA3 chelates when HA alone is used. In the presence of HA and Phen, both LnA3(Phen) and LnA3(Phen)2 adducts are formed only in the MIBK system while LnA3(Phen) complexes are the predominant ones in all other solvent systems studied. The extraction constants and the adduct formation constants of these complexes have been calculated.

Fixing part containing ceramur composition

Abstract: PURPOSE: To provide an overcoat of a ceramer composition excellent in durability, wear resistance and release performance and also having one or more deterioration resistances to a toner additive such as a charge control agent by constituting the parts of a supporting substrate and a layer consisting of an integrally mutually permeated network of a haloelastomer and silica. CONSTITUTION: A base member 4 is a hollow cylinder formed of suitable metal such as aluminum. A ceramer is obtained by dissolving a haloelastomer of preferably 1-35wt.% in a suitable liquid solution such as aliphatic hydrocarbon including methyl ethyl ketone, methyl isobutyl ketone and the like preferably at 25 deg.C. To this, the required quantity of an amine base coupler and a silane compound are effectively and continuously added. In this, another compound for making the production of a ceramer easy such as a curing agent may be contained. The formation of the effective layer of a ceramer on the supporting substrate is attained by a suitable well-known method such as spraying.

Process for the preparation of polyurethane

Abstract: The anionic aqueous polyurethene adhesive coupsn. is prepd. by reacting, w.r.t. total solid component, 30-70wt.% of polyol comprising 0.5-20% mole of polyester polyol/polyether polyol, 20-35wt.% of diisocyanate, 5-10wt.% of chain extender, and 0.1-1.0wt.% of crosslinking agent in lower boiling point polymerization solvent, in the presence of a catalyst; neutralizing by alkali water solution; then distillating and removing the solvent. Pref. the lower boiling point polymerization solvent is used in the amount of 20-70wt.% w.r.t. total polyurethane component, to two or more of tetrahydrofuran, cyclohexane, acetone, methyletuyl ketone, methyl isobutyl ketone, ethyl acetate, N-methyl pyrrolidone or toluene.

Isolation and separation of tantalum and niobium

Abstract: Tantalum and niobium are recovered from raw materials contg. both elements by: digestion (fusion) using exclusively HF; sepn. of Ta and Nb from accompanying elements; sepn. of Ta and Nb from each other as fluoro-complexes by solvent extn. of the fusion soln. using methyl isobutyl ketone (MIBK); washing the loaded MIBK with exclusively water. The resultant aq. wash soln. is removed separately from the extn. operation.

Use of the electrically-driven emulsion phase contactor in chemical and biochemical processing

Abstract: An electrically driven liquid-liquid contactor has been developed to enhance the efficiency of chemical and biochemical processes. A uniform electric field is utilized to induce a drop dispersion- coalescence cycle, producing high surface area for interfacial mass transfer under continuous-countercurrent-flow conditions. The mass- transport capability of this system has been analyzed by observing the extraction of acetic acid from water (dispersed phase) into methyl isobutyl ketone. Results showed that, due to increased efficiency of mass transfer, the electrically-driven device could be an order of magnitude smaller than a conventional contactor accomplishing the same level of separation. In the case of biochemical processes within non-aqueous environments, a biocatalyst (enzymes or bacteria) is introduced in the aqueous (dispersed) phase. The biocatalyst uses nutrients and other reactants to selectively transform species transferred from the continuous (organic) phase to the interior of the drops. An example of such system that has been investigated is the oxidation of p-cresol dissolved in toluene by aqueous-phase horseradish peroxidase.