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101.
Fernand Pla Christian Fonteix Sandrine Hoppe Cornelius Schrauwen Hanno Van der Wal Freddy Van Damme 《Macromolecular Symposia》2007,259(1):53-64
Summary: This work deals with the development of a process for the radical copolymerization of acrylonitrile and styrene in a dispersed medium. This process was carried out in a continuous stirred tank reactor, in the presence of a stabilizing agent produced in situ during the polymerization. The continuous phase is a polyol. Besides all elementary chemical mechanisms related to the copolymerization and to the synthesis and grafting of the stabilizing agent, this process involves several complex physical phenomena. A tendency model of the whole process was developed, using the corresponding mass balances and thermodynamics. Its unknown parameters were identified by use of an evolutionary algorithm and experimental data resulting from an adapted experimental strategy. This model was then validated and allowed to predict monomers and transfer agent conversions, amounts of solids and average molar masses, versus the operating conditions. 相似文献
102.
Jonathan Leblanc Mathilde Mercier Christian Fonteix Fernand Pla 《Macromolecular Symposia》2007,259(1):85-93
Summary: This work deals with the development of the dispersed phase morphology in immiscible blends of poly(ethylene glycol)/polyamide 66 (PEG/PA) with an extremely low viscosity ratio. The blends were obtained, under different operating conditions, by melt blending in an internal mixer. The objective was to examine the influence of the main processing parameters on the particles size of the minor phase (PEG). A model was elaborated to describe the dependence of the particle size on interfacial tension, PEG concentration, shear rate and viscosity ratio between the two blend components. 相似文献
103.
In this article, a novel methodology for the study of complex reaction mechanisms is explored, and applied to the kinetic analysis of the hydrolysis reactions of ciclohexanecarbonitriles. The kinetic data were first analyzed with the help of classic linear techniques. Subsequently, the determination of the rate constants by a non‐linear, least‐squares (LS) fitting method, followed by a novel eigenvalue‐eigenvector analysis of the sensitivity coefficients, permitted us to obtain the maximum possible information from the kinetic data. The non‐linear, LS‐fitting method, carried out by means of a new version of OPKINE program, allowed the calculation of all the rate constants of the mechanism; in addition, the sensitivity analysis permitted us to establish the uniqueness and reliability of calculated rate coefficients. Finally, the results of the sensitivity analysis were tested by means of a simulation procedure, and the results compared to those obtained from classic linear methods. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 611–626, 1999. 相似文献
104.
Jean-François Stoltz Rodolphos Jose Rasia Juana Rosa Valverde L. Pla Danielle Sontag Alain Rapaille S. Muller 《Rheologica Acta》2000,39(6):595-600
The adhesive energy of monoclonal antibody induced agglutination can be assessed from the shear dissociation of agglutinates.
Anti-A, anti-B, and anti-AB monoclonal antibodies agglutinate erythrocytes with variable strength, depending on the affinity
of antibodies and on the antigenic density on the cell surface. The time required for an applied shear stress to dissociate
cell agglutinates completely is depending on the strength of the agglutination reaction. The dissociation process under constant
shear stress can be followed by measuring intensity of light backscattered by suspended particles. The obtained dissociation
curves could be adjusted by an exponential expression governed by a parameter called characteristic time of dissociation.
This parameter decreases with increasing antibody concentration. Integration of dissociation curves provided an approach of
adhesive energy induced by monoclonal antibody.
Received: 7 May 1999 Accepted: 30 May 2000 相似文献
105.
Analytical and Bioanalytical Chemistry - 相似文献
106.
107.
Stereoselective Rhodium‐Catalysed [2+2+2] Cycloaddition of Linear Allene–Ene/Yne–Allene Substrates: Reactivity and Theoretical Mechanistic Studies 下载免费PDF全文
Ewelina Haraburda Òscar Torres Dr. Teodor Parella Prof. Dr. Miquel Solà Dr. Anna Pla‐Quintana 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):5034-5045
Allene–ene–allene ( 2 and 5 ) and allene–yne–allene ( 3 and 7 ) N‐tosyl and O‐linked substrates were satisfactorily synthesised. The [2+2+2] cycloaddition reaction catalysed by the Wilkinson catalyst [RhCl(PPh3)3] was evaluated. Substrates 2 and 5 , which bear a double bond in the central position, gave a tricyclic structure in a reaction in which four contiguous stereogenic centres were formed as a single diastereomer. The reaction of substrates 3 and 7 , which bear a triple bond in the central position, gave a tricyclic structure with a cyclohexenic ring core, again in a diastereoselective manner. All cycloadducts were formed by a regioselective reaction of the inner allene double bond and, therefore, feature an exocyclic diene motif. A Diels–Alder reaction on N‐tosyl linked cycloadducts 8 and 10 allowed pentacyclic scaffolds to be diastereoselectively constructed. The reactivity of the allenes on [2+2+2] cycloaddition reactions was studied for the first time by density functional theory calculations. This mechanistic study rationalizes the order in which the unsaturations take part in the catalytic cycle, the reactivity of the two double bonds of the allene towards the [2+2+2] cycloaddition reaction, and the diastereoselectivity of the reaction. 相似文献
108.
Friedel-Crafts acylation of ferrocene with alkynoic acids 总被引:1,自引:0,他引:1
Damian Pla?uk 《Journal of organometallic chemistry》2009,694(12):1802-3506
Ferrocene reacts with alkynoic acids (conjugated or nonconjugated terminal), trifluoroacetic anhydride and triflic acid (or boron trifluoride etherate) to afford the corresponding ferrocenyl ynones in good yields. Only in the case of propynoic- and 3-butynoic acid complex, untreatable reaction mixtures were obtained. However, propynoilferrocene was obtained by desilylation of (trimethylsilyl)propynoilferrocene with KF/18-crown-6. Reaction with nonconjugated terminal alkynoic acids, carried out in the presence of a large excess of triflic acid (4 equiv.) results in formation of complex mixtures of products (in the reaction with 4-pentynoic acid enol triflate of ferrocenyl 1,4-diketone and 2-ferrocenyl-5-methylfuran were isolated). Ferrocenyl ynones obtained in this work can be used for synthesis of more complex ferrocenyl systems by “click” chemistry. 相似文献
109.
Atamestane (SH 489) was synthesized from 17β-Acetoxy-1α-methyl-5α-androstan-3-one. Thus dibromination followed by dehydrobromination of the A-ring gave dienone (5) in good yield, which was hydrolyzed and oxidized to give the title compound in 60% overall yield. 相似文献
110.
Ioannis J. Stavrou Leonard Moore Jr. Vivian E. Fernand Constantina P. Kapnissi‐Christodoulou Isiah M. Warner 《Electrophoresis》2013,34(9-10):1334-1338
In this study, the dissolution of polysaccharides into an ionic liquid was investigated and applied as a coating onto the capillary walls of a fused‐silica capillary in open‐tubular CEC. The coating was evaluated by examining the chiral separation of two analytes (thiopental, sotalol) with three cellulose derivatives (cellulose acetate, cellulose acetate phthalate, and cellulose acetate butyrate). Baseline separation of thiopental enantiomers was achieved by use of each polysaccharide coating (Rs: 7.0, 8.1, 7.1), while sotalol provided partial resolution (Rs: 0.7, 1.0, 0.9). In addition, reproducibility of the cellulose‐coated capillaries was evaluated by estimating the run‐to‐run and capillary‐to‐capillary RSD values of the EOF. Both stability and reproducibility were very good with RSD values of less than 7%. 相似文献