Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

In Situ FT-IR Studies on the Catalytic Reaction Kinetics of 1,2-Propanediol with Phenyl Isocyanate

2012 ◽  
Vol 450-451 ◽  
pp. 131-134
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Phenyl Isocyanate ◽  
Activation Entropy ◽  
Ir Studies ◽  
Initial Stage ◽  
Different Temperatures ◽  
Ft Ir ◽  
Kinetics Of

Phenyl isocyanate is used to react with 1,2-propanediol in different temperatures. Toluene is used as solvent and triethylamine is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction are calculated out, which are 74.1 kJ•mol-1, 71.3 kJ•mol-1 and -30.5 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.

In Situ FT-IR Studies on the Amine-Catalyzed Urethane Reaction Kinetics of 1,3-Butanediol

2012 ◽  
Vol 472-475 ◽  
pp. 2223-2226
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Phenyl Isocyanate ◽  
Hydroxyl Group ◽  
Activation Entropy ◽  
Ir Studies ◽  
Initial Stage ◽  
Different Temperatures ◽  
Ft Ir ◽  
Kinetics Of

Phenyl isocyanate is used to react with 1,3-butanediol at different temperatures. Toluene is used as solvent and 1,4-diazabicyclo[2,2,2]octane is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of primary hydroxyl group are calculated out, which are 26.4 kJ•mol-1, 23.6 kJ•mol-1and -186.6 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.

In Situ FT-IR Studies on the Urethane Reaction Kinetics of 3-Methyl-1,3-Butanediol in Nitrogen-Contained Solvent

2012 ◽  
Vol 446-449 ◽  
pp. 1743-1746
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Phenyl Isocyanate ◽  
Hydroxyl Group ◽  
Activation Entropy ◽  
Ir Studies ◽  
Initial Stage ◽  
Different Temperatures ◽  
Ft Ir ◽  
Kinetics Of

Phenyl isocyanate is used to react with 3-methyl-1,3-butanediol at different temperatures. Dimethylformamide is used as solvent. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of tertiary hydroxyl group are calculated out, which are 75.2 kJ•mol-1, 72.4 kJ•mol-1and -44.8 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.

In Situ FT-IR Studies on the Urethane Reaction Kinetics of 1,3-Butanediol in Nitrogen-Contained Solvent

2012 ◽  
Vol 472-475 ◽  
pp. 1911-1914
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Phenyl Isocyanate ◽  
Hydroxyl Group ◽  
Activation Entropy ◽  
Ir Studies ◽  
Initial Stage ◽  
Different Temperatures ◽  
Ft Ir ◽  
Kinetics Of

Phenyl isocyanate is used to react with 1,3-butanediol at different temperatures. Dimethylformamide is used as solvent. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of primary hydroxyl group are calculated out, which are 90.9 kJ•mol-1, 88.2 kJ•mol-1and 20.2 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.

In Situ FT-IR Studies on the Catalytic Reaction of Isophorone Diisocyanate with Benzyl Alcohol

2012 ◽  
Vol 476-478 ◽  
pp. 2197-2200
Author(s):  
Peng Fei Yang
Keyword(s):  
Benzyl Alcohol ◽  
Rate Constant ◽  
Dibutyltin Dilaurate ◽  
Activation Entropy ◽  
Isophorone Diisocyanate ◽  
Ir Studies ◽  
Initial Stage ◽  
Different Temperatures ◽  
Ft Ir

Benzyl alcohol is used to react with isophorone diisocyanate at different temperatures. Dibutyltin dilaurate is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of different isocyanates groups are respectively calculated out, which are very useful to reveal the reaction mechanism.

Kinetic Studies of Isophorone Diisocyanate-Polyether Polymerization with in situ FT-IR

2011 ◽  
Vol 16 (8) ◽  
pp. 584-590 ◽  
Author(s):  
Peng Fei Yang ◽  
Yan Hong Yu ◽  
Shun Ping Wang ◽  
Tian Duo Li
Keyword(s):  
Kinetic Studies ◽  
Isophorone Diisocyanate ◽  
Ft Ir

Effects of Solvent Polarity on the Urethane Reaction of 1,2-Propanediol

2012 ◽  
Vol 450-451 ◽  
pp. 38-41
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Solvent Polarity ◽  
Reaction Rates ◽  
Phenyl Isocyanate ◽  
Second Order Reaction ◽  
Polar Solvents ◽  
Initial Stage ◽  
Ft Ir ◽  
Kinetics Of

The urethane reaction kinetics of 1,2-propanediol with phenyl isocyanate are investigated in different solvents, such as xylene, toluene and dimethylformamide. In-situ FT-IR is used to monitor the reaction to work out rate constant. It showsthat the urethane reaction has been found to be a second order reaction, solvents largely affects reaction rates. The reaction is largely accelerated in polar solvents, following the order of dimethylformamide > toluene > xylene. Further more, when dimethylformamide is used as solvent, the rate constants are different between initial stage and final stage, which belongs to different hydroxyls in 1,2-propanediol. However, when toluene or xylene is used as solvent, the rate constant is the same. That is, there is no reactivity difference for hydroxyls in 1,2-propanediol.

Use of Entropy Minimization for the Preconditioning of Large Spectroscopic Data Arrays: Application to in Situ FT-IR Studies from the Unmodified Homogeneous Rhodium Catalyzed Hydroformylation Reaction

2002 ◽  
Vol 56 (11) ◽  
pp. 1422-1428 ◽  
Author(s):  
Li Chen ◽  
Marc Garland
Keyword(s):  
Spectroscopic Data ◽  
Kinetic Studies ◽  
Critical Issue ◽  
Pure Component ◽  
Sequential Reaction ◽  
Single Experiment ◽  
Entropy Minimization ◽  
Ir Studies ◽  
Ft Ir

In situ spectroscopic measurements are fairly common in homogeneous catalysis. However, although it is easy to accumulate vast amounts of data, their appropriate analysis becomes a critical issue. Accordingly, we have developed a simple-to-implement but numerically sophisticated tool. Let A denote a matrix of absorbance data, n denote the number of preliminary spectra obtained from the stepwise addition of reagents, k denote the number of sequential reaction spectra, and v the spectroscopic channels. Then the preconditioning problem can be stated as [Formula: see text]. A single experiment results in (1) a set of n “pure” component reference spectra and (2) a set of k preconditioned reaction spectra where the reagents have been optimally subtracted. Entropy minimization is examined as a means of achieving both objectives. The developed algorithm was applied to a set of FT-IR spectra obtained from a complex transition-metal homogeneous catalyzed organic synthesis. Excellent reference spectra and excellent preconditioned reaction spectra were readily obtained. In addition, the absorbance of the products in the preconditioned spectra was compared to the absorbance obtained after manual user-defined subtraction. Comparable results were obtained. The present approach is clearly useful for the automated numerical treatment of very large sequential spectroscopic data arrays arising from in situ kinetic studies. Extension to related types of problems in the chemical sciences and to other spectroscopic methods such as NMR are obvious.

Catalytic Effect of Triethylamine on the Urethane Reaction of Asymmetry Diol

2012 ◽  
Vol 472-475 ◽  
pp. 1837-1840
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Catalytic Effect ◽  
Reaction System ◽  
Phenyl Isocyanate ◽  
Order Reaction ◽  
Second Order Reaction ◽  
Initial Stage ◽  
Ft Ir ◽  
Kinetics Of

The urethane reaction kinetics of 1,2-propanediol and 1,3-butanediol with phenyl isocyanate are investigated in toluene. In-situ FT-IR is used to monitor the reaction to work out rate constant. The urethane reaction has been found to be a second order reaction and is largely accelerated with triethylamine as catalyst. Furthermore, the rate constants are different between initial stage and final stage when triethylamine is used as catalyst, which belongs to different hydroxyls in asymmetry diol. However, when there is no catalyst in the reaction system, the rate constant is the same. That is, there is no reactivity difference for hydroxyls in asymmetry diol. Moreover, 1,3-butanediol is more active than 1,2-propanediol when reacting with isocyanate.

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