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Byeng-gil Ahn - One of the best experts on this subject based on the ideXlab platform.
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Electrorheological Properties of Phosphoric Ester Cellulose Electrorheological Suspensions with Activation of Dispersed Particles
Polymer Journal, 2003Co-Authors: Byeng-gil AhnAbstract:The electrorheological (ER) behavior of activated ER suspensions in silicone oil of Phosphoric Ester cellulose powder (average particle size : 17.77 μm) was investigated at room temperature with electric fields up to 2.5 kV mm^-1. For increasing ER effect of ER suspensions, activating effect of dispersed particles, Phosphoric Ester cellulose, on ER activity was studied. Anhydrous ER suspensions based on Phosphoric Ester cellulose particles made from cellulose treated in chemical solution of 2 M Phosphoric acid and 4 M urea, heated at 150 °C and crushed were measured. After activating the dispersed particles in anhydrous ER suspensions at 120 °C, analysis of the dispersed Phosphoric Ester cellulose particles was made. ER properties of ER suspensions such as dielectric constant, current density, electrical conductivity, and rheological properties were studied. Activating of dispersed particles had large influence on ER activities of anhydrous ER suspensions based on Phosphoric Ester cellulose. With activation time, particle size, and number of dispersed particles per unit volume, electrical properties, dynamic yield stress on electric field, initial apparent viscosity (η_0), and ER effect (τ_A/τ_0) of Phosphoric Ester cellulose ER suspensions increased at 120 °C.
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Electrorheological Properties of Phosphoric Ester Cellulose Electrorheological Suspensions at Elevated Temperatures
Polymer Journal, 2000Co-Authors: Byeng-gil Ahn, Ung-soo Choi, Oh-kwan KwonAbstract:The electrorheological (ER) behavior of suspensions in silicone oil of Phosphoric Ester cellulose powder (average particle size: 17.77 μm was investigated at elevated temperatures up to 100°C. For development of anhydrous ER suspensions for use at wide temperature range, the effect of temperature on ER activity has studied. Anhydrous ER suspensions were mixed with the Phosphoric Ester cellulose particles made from the Phosphoric Ester reactions of cellulose. During increasing temperature, not only analysis of electrical properties, such as dielectric constant, current density and electrical conductivity but also rheological properties of ER suspensions were studied. Current density, conductivity and electrorheological effect (τ_A/τ_0) of Phosphoric Ester cellulose ER suspensions showed law dependence on temperature. Shear stress was closely related to the square of dielectric constant mismatch parameter (β^2) under constant shear rate and electric field.
Oh-kwan Kwon - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Activation Time of Phosphoric Ester Cellulose Particles on the Electrorheological Properties of Anhydrous ER Fluids
International Journal of Modern Physics B, 2001Co-Authors: Ung-su Choi, Oh-kwan KwonAbstract:The electrorheological (ER) behavior of suspensions in silicone oil of Phosphoric Ester cellulose powder (average particle size: 17.77 μm) was investigated at room temperature with electric fields up to 2.5 kV/mm. For development of anhydrous ER fluids using at wide temperature range, it was sought the effect of activation time of Phosphoric Ester cellulose particles on the ER activities. Anhydrous ER fluids based on the Phosphoric Ester cellulose particles made from cellulose particles treating in chemical solution of 2M Phosphoric acid and 4M urea and heating at 150°C were measured. After activating the Phosphoric Ester cellulose anhydrous ER fluids at 120°C, not only analysis of dispersing cellulose particles but also electroroheological characteristics of ER fluids such as dielectric constant, current density, electrical conductivity and rheological properties were studied. Activation time had a large influence to ER properties of anhydrous ER fluids based on Phosphoric Ester cellulose. As the activation time went by, particle size and number of dispersing particles, electrical properties, dynamic yield stress on electric field, initial apparent viscosity (η0) and electrorheological effect (τA/τ0) of Phosphoric Ester cellulose ER fluids increased with increasing activation time at 120°C till activation time over 5 hours.
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Electrorheological Properties of Phosphoric Ester Cellulose Electrorheological Suspensions at Elevated Temperatures
Polymer Journal, 2000Co-Authors: Byeng-gil Ahn, Ung-soo Choi, Oh-kwan KwonAbstract:The electrorheological (ER) behavior of suspensions in silicone oil of Phosphoric Ester cellulose powder (average particle size: 17.77 μm was investigated at elevated temperatures up to 100°C. For development of anhydrous ER suspensions for use at wide temperature range, the effect of temperature on ER activity has studied. Anhydrous ER suspensions were mixed with the Phosphoric Ester cellulose particles made from the Phosphoric Ester reactions of cellulose. During increasing temperature, not only analysis of electrical properties, such as dielectric constant, current density and electrical conductivity but also rheological properties of ER suspensions were studied. Current density, conductivity and electrorheological effect (τ_A/τ_0) of Phosphoric Ester cellulose ER suspensions showed law dependence on temperature. Shear stress was closely related to the square of dielectric constant mismatch parameter (β^2) under constant shear rate and electric field.
Ung-soo Choi - One of the best experts on this subject based on the ideXlab platform.
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Electrorheological Properties of Phosphoric Ester Cellulose Electrorheological Suspensions at Elevated Temperatures
Polymer Journal, 2000Co-Authors: Byeng-gil Ahn, Ung-soo Choi, Oh-kwan KwonAbstract:The electrorheological (ER) behavior of suspensions in silicone oil of Phosphoric Ester cellulose powder (average particle size: 17.77 μm was investigated at elevated temperatures up to 100°C. For development of anhydrous ER suspensions for use at wide temperature range, the effect of temperature on ER activity has studied. Anhydrous ER suspensions were mixed with the Phosphoric Ester cellulose particles made from the Phosphoric Ester reactions of cellulose. During increasing temperature, not only analysis of electrical properties, such as dielectric constant, current density and electrical conductivity but also rheological properties of ER suspensions were studied. Current density, conductivity and electrorheological effect (τ_A/τ_0) of Phosphoric Ester cellulose ER suspensions showed law dependence on temperature. Shear stress was closely related to the square of dielectric constant mismatch parameter (β^2) under constant shear rate and electric field.
Polezhaeva N. - One of the best experts on this subject based on the ideXlab platform.
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β-Keto phosphonic Esters - Communication 5. Structures of the products of the reaction of some α-halo ketones of the carbocyclic series with triethyl phosphite and sodium diethyl phosphite
2020Co-Authors: Arbuzov B., Polezhaeva N.Abstract:1. On the basis of chemical and spectrographic data it was shown that the product of the action of sodium diethyl phosphite on 2-chlorocyclopentanone is diethyl 1,2-epoxycyclopentylphosphonate. The product of the action of sodium diethyl phosphite on 2 -bromocyelohexanone is a mixture of 1-cyclohexen-1-yl diethyl phosphate and diethyl 1,2-epoxycyclohexylphosphonate. 2. The products of the action of sodium diethyl phosphite and of triethyl phosphite on 2-chloro-2-methyl-cyclohexanone consist of diethyl 2-methyl-1-cyclohexen-1-yl phosphate; the product of the action of triethyl phosphite on 3-bromo-3-methyl-2-butanone is diethyl isopropenyl phosphate. 3. The product of the action of sodium diethyl phosphite on 3-bromocamphor is the corresponding mixed Phosphoric Ester. © 1961 Consultants Bureau Enterprises, Inc
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Esters of β-ketophosphonic acids - Communication 8. Reaction of 2,6-dibromocyclohexanone with triethyl phosphite
2020Co-Authors: Arbuzov B., Polezhaeva N.Abstract:1. The reaction of triethyl phosphite with 2,6-dibromocyclohexanone follows a complex course. In addition to the expected diethylPhosphoric Ester of the enol form of the Ester of cyclohexanone-2-phosphonic-1 acid, by-products are formed which are produced by conversions of the latter compound (diethyl Ester of cyclohexanone-2-phosphonic-1 acid and tetraethyl Ester of hypoPhosphoric acid), and also an intermediate product, diethyl bromo-6-cyclohexen-1-yl Phosphoric Ester [diethylcyclohexadien-1,5-yl phosphate, diethyl phenyl phosphate]. 2. The cis- and trans-isomers of 2,6-dibromocyclohexanone react differently with triethyl phosphite. The trans-isomer gives the diethylPhosphoric Ester of the enol form of the Ester of cyclohexanone-2-phosphonic-1 acid as the main reaction product. With the cis-form the diethyl Ester of cyclohexanone-2-phosphonic-1 acid is formed. In both cases, the products enumerated in paragraph 1 also are obtained. © 1962 Consultants Bureau Enterprises, Inc
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Esters of β-ketophosphonic acids - Communication 9. Reaction of 2,6-dibromo- and 2,6-dichlorocyclohexanone with one and two moles of triethyl phosphite
2020Co-Authors: Arbuzov B., Polezhaeva N.Abstract:1. The reaction of trans-2,6-dibromocyclohexanone with one and two molecules of triethyl phosphite follows a complex course. The reaction with one molecule of triethyl phosphite stops at the stage of formation of the diethyl bromo-6-cyclohexen-1-yl Ester of Phosphoric acid, which is further converted to diethyl cyclohexadien-1,3-yl-2 phosphate and diethyl phenyl phosphate. The diethyl Phosphoric Ester of the enol form of the Ester of cyclohexanone-2-phosphonic-1 acid is not produced in this process. 2. The cis- and trans-isomers of 2,6-dichlorocyclohexanone reacr with two molecules of triethyl phosphite with the formation of diethyl chloro-6-cyclohexen-1-yl Ester of Phosphoric acid. 3. The bromination of the diethyl cyclohexenyl Ester of Phosphoric acid with bromosuccinimide with subsequent treatment with triethyl phosphite does not lead to the diethylPhosphoric Ester of the enol form of cyclohexan-one-2-phosphonic-1 acid. A mixture of products is formed similar to the mixture obtained when triethyl phosphite acts on cis-2,6-dibromocyclohexanone. © 1962 Consultants Bureau Enterprises, Inc
Yoshiharu Kimura - One of the best experts on this subject based on the ideXlab platform.
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controlled crystal nucleation in the melt crystallization of poly l lactide and poly l lactide poly d lactide stereocomplex
Polymer, 2003Co-Authors: Hiroshi Urayama, Takeshi Kanamori, Kazuki Fukushima, Yoshiharu KimuraAbstract:Abstract Among the various inorganic nucleators examined, Talc and an aluminum complex of a Phosphoric Ester combined with hydrotalcite (NA) were found to be effective for the melt-crystallization of poly( l -lactide) (PLLA) and PLLA/poly( d -lactide) (PDLA) stereo mixture, respectively. NA (1.0 phr (per one hundred resin)) can exclusively nucleate the stereocomplex crystals, while Talc cannot suppress the homo crystallization of PLLA and PDLA in the stereo mixture. Double use of Talc and NA (in 1.0 phr each) is highly effective for enhancing the crystallization temperature of the stereo complex without forming the homo crystals. The stereocomplex crystals nucleated by NA show a significantly lower melting temperature (207 °C) than the single crystal of the stereocomplex (230 °C) in spite of recording a large heat of crystallization ΔHc (54 J/g). Photomicrographic study suggests that the spherulites with a symmetric morphology are formed in the stereo mixture added with NA while the spherulites do not grow in size in the mixture added with Talc. The exclusive growth of the stereocomplex crystals by the melt-crystallization process will open a processing window for the PLLA/PDLA.
