Kinetic study of organotin catalyzed alcohol-isocyanate reactions Part 2: Inhibition by foreign substances in acetonitrile and toluene

Draye, Anne-Cécile; Tondeur, J. J.

doi:10.1016/s1381-1169(98)00209-x

Cited by 23 publications

(6 citation statements)

References 3 publications

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Section: Resultsmentioning

confidence: 99%

“…Another possibility is the previous activation of the alcohol by the Tin catalyst followed by complexation of the isocyanate compound with subsequent formation of a urethane product. 6,49,50 A proposed mechanism of the catalytic process is represented in Scheme 2. 51 Reports mention there is deceleration of the isocyanate-alcohol reaction rate due to the production of small amounts of carboxylic acids from the alcoholysis of Sn-(Tin II catalyst) with OH R (polyol).…”

Section: Double Peaks Phenomenon Is Observed For All Pus Compoundsmentioning

confidence: 99%

“…6,49,50 A proposed mechanism of the catalytic process is represented in Scheme 2. 51 Reports mention there is deceleration of the isocyanate-alcohol reaction rate due to the production of small amounts of carboxylic acids from the alcoholysis of Sn-(Tin II catalyst) with OH R (polyol).…”

Section: Double Peaks Phenomenon Is Observed For All Pus Compoundsmentioning

confidence: 99%

“…Conversion of isocyanate as a function of temperature composition S C H E M E 2 Urethane-formation catalyzed by Tin alcoholate reaction rate, probably resulting from a competition between alcoholysis and hydrolysis of dialkyltin dicarboxylate. [49][50][51] Assuming the complete curing as C 1 + C 2 , the curing may be analyzed separately. The two peaks were integrated to compute the degree of conversion (α) and curing rates (dα/dt), which are illustrated in Figure 9.…”

Section: Double Peaks Phenomenon Is Observed For All Pus Compoundsmentioning

confidence: 99%

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Curing and morphology approaches of polyurethane/poly(ethylene glycol) foam upon poly(lactic acid) addition

Almeida

Albuquerque

Silva

et al. 2022

Polymers for Advanced Techs

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The effect of poly(lactic acid) (PLA) content on the curing of polyethylene glycol (PEG) based polyurethanes (PU) was investigated. Aiming to produce biobased PU foams, pentamethylene diisocyanate (PDI) was used. Fourier transform infrared spectroscopy (FTIR) found no curing evidence at 30 C and verified that the curing was completed at 300 C. This method tracks hydrogen bonding and NCO consumption.

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Section: Resultsmentioning

confidence: 99%

Section: Double Peaks Phenomenon Is Observed For All Pus Compoundsmentioning

confidence: 99%

Section: Double Peaks Phenomenon Is Observed For All Pus Compoundsmentioning

confidence: 99%

Section: Double Peaks Phenomenon Is Observed For All Pus Compoundsmentioning

confidence: 99%

See 2 more Smart Citations

Curing and morphology approaches of polyurethane/poly(ethylene glycol) foam upon poly(lactic acid) addition

Almeida

Albuquerque

Silva

et al. 2022

Polymers for Advanced Techs

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“…So far, mechanistic studies on metal complex catalyzed PU reaction have been performed mainly for organotin catalysts, 58,[60][61][62][63][64][65] leaving critical questions still unanswered. It remains for example unclear what factors determine the selectivity and speed of the isocyanate-hydroxyl reaction when catalyzed by tin, zirconium, bismuth, or zinc catalysts.…”

Section: Mechanistic Investigation and Density Functional Theory Calcmentioning

confidence: 99%

Heterobimetallic complexes composed of bismuth and lithium carboxylates as polyurethane catalysts – alternatives to organotin compounds

et al. 2021

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Fluoropolyethers end-capped by polar functional groups. II. Effect of catalyst and reagents concentration, solvent nature, and temperature on reaction kinetics of ?,?-bis(hydroxy)-terminated fluoropolyethers with cycloalyphatic and aromatic diisocyanates

Mashlyakovskiy

Khomko

Zaiviy

et al. 2000

J. Polym. Sci. A Polym. Chem.

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A comparative kinetic study of the dibutyltin dilaurate (DBTDL) and 1,4‐diazabicyclo[2,2,2]octane (DABCO) catalyzed reactions of α,ω‐bis(hydroxy)‐terminated fluoropolyethers (FPEs)—Z‐DOLs and Z‐DOL TXs—of various molecular weights and purity, with 4,4′‐dicyclohexylmethane diisocyanate (H12MDI), isophorone diisocyanate (IPDI) and 2,4‐toluene diisocyanate (TDI) was carried out in different solvents. An analytical method was used to follow the kinetics of the reactions at four different temperatures. The rate of NCO disappearance measured by two independent methods—IR spectroscopy and chemical titration were found to be very close. Straight proportionality between rate constants kcat and catalyst concentration was found. But in some cases for the DBTDL catalyzed reactions effect of catalyst saturation along with appearance of the limiting DBTDL concentration Clim below which the rate of reaction was close to zero were observed. Reactivity of Z‐DOLs in the tin‐catalyzed urethane reactions was found to decrease with their storage time at RT due to the slow hydrolysis of the end COOR groups impurities, which give the corresponding acids that act as a strong inhibitor of the DBTDL activity. These acid admixtures have no influence on the DABCO catalyzed reactions. For the DBTDL and DABCO catalyzed reactions of Z‐DOLs with IPDI the dependence of effective rate constants keff (where keff = kcat · 0.01/[DBTDL] and catalyst concentration is taken in mol % based on IPDI) on total reagents concentration were found to be described by curves with a maximum. Critical reagents concentration, after which the relationship keff = f (C) changes from proportional to inverse proportional, seems do not substantially depend on the solvent nature. Hydrogenated analog poly(ethylene glycol) MW 400 (PEG‐400) differs greatly from Z‐DOLs: only steady decrease of keff was observed with increase of reagents concentration C from 5 up to 95 wt %. Activation energies for all the studied reactions are within the range of 10.8–16.7 kcal/mol. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2579–2602, 2000

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Kinetic study of organotin catalyzed alcohol-isocyanate reactions Part 2: Inhibition by foreign substances in acetonitrile and toluene

Cited by 23 publications

References 3 publications

Curing and morphology approaches of polyurethane/poly(ethylene glycol) foam upon poly(lactic acid) addition

Curing and morphology approaches of polyurethane/poly(ethylene glycol) foam upon poly(lactic acid) addition

Heterobimetallic complexes composed of bismuth and lithium carboxylates as polyurethane catalysts – alternatives to organotin compounds

Fluoropolyethers end-capped by polar functional groups. II. Effect of catalyst and reagents concentration, solvent nature, and temperature on reaction kinetics of ?,?-bis(hydroxy)-terminated fluoropolyethers with cycloalyphatic and aromatic diisocyanates

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