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.

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.

The Amount Effect of Catalyst on the Urethane Reaction of 1,2-Propanediol in Xylene

2012 ◽  
Vol 450-451 ◽  
pp. 197-200 ◽  
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constants ◽  
Catalyst Concentration ◽  
Phenyl Isocyanate ◽  
Order Reaction ◽  
Second Order Reaction ◽  
Amount Effect ◽  
Initial Stage ◽  
Ft Ir ◽  
Kinetics Of

The urethane reaction kinetics of 1,2-propanediol with phenyl isocyanate is monitored with in-situ FT-IR with xylene as solvent. Triethylamine is used as catalyst and its amount effect is investigated. Rate constants for the reaction with different concentrations of triethylamine are worked out. The urethane reaction has been found to be a second order reaction and the reaction is largely accelerated with the increase of catalyst concentration. Furthermore, when triethylamine is used as catalyst, the rate constants are different between initial stage and final stage, which belong to different hydroxyls in 1,2-propanediol. However, the rate constant is the same when there is no catalyst, which shows no reactivity difference for hydroxyls in 1,2-propanediol.

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 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 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 the reactions between isocyanates and carboxylic acids

1994 ◽  
Vol 6 (3) ◽  
pp. 235-239 ◽  
Author(s):  
Hong Xiao ◽  
Han X Xiao ◽  
Kurt C Frisch ◽  
Nelson Malwitz
Keyword(s):  
Carboxylic Acids ◽  
Reaction Kinetic ◽  
Arrhenius Plot ◽  
Kinetic Studies ◽  
Isobutyric Acid ◽  
Phenyl Isocyanate ◽  
Order Reaction ◽  
Second Order Reaction ◽  
Different Temperatures ◽  
Kinetics Of

Reaction kinetic studies between isocyanates and carboxylic acids were undertaken to evaluate the kinetic parameters. Various isocyanates (phenyl isocyanate, cyclohexyl isocyanate) and carboxylic acids (acetic acid, n-butyric acid, isobutyric acid, dimethylbutyric acid and benzoic acid) were used to study the kinetics of the reactions at different temperatures and in different solvents. It was found that these reactions followed the rate law of second-order reaction. From the Arrhenius plot, the activation energies of these reactions were computed.

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