Temeprature effect on alcohol—isocyanate kinetics

Abstract

The kinetics of the reaction of cyclopentanol with PhNCO or OCN(Cd-In)NCO was studied in toluene, di-n-butyl ether and acetonitrile. The results suggest a predominant influence of the aggregation state of alcohol.

On the Versatility of Urethane/Urea Bonds: Reversibility, Blocked Isocyanate, and Non-isocyanate Polyurethane

“…The n−π* transition of CO absorbs at 282−283 nm. Tondeur et al 28,52,53 studied cyclopentanol−phenylisocyanate kinetics of reaction by calculating the conversion ratio according to eq 10: (10) where A 282 stands for absorbance at 282 nm and ε NCO and ε ure stand for the extinction coefficients of phenylisocyanate and urethane, respectively. When heat is applied to blocked isocyanate adducts, the urethane linkage scission leads to an endothermic transition in the DSC curve, possibly preceded by a sharp transition that corresponds to the adduct melting.…”

Di- and tri-organotin(IV) complexes of the new bis(1-methyl-1H-imidazol-2-ylthio)acetate ligand and the decarboxylated analogues

“…Many organotin compounds have been tested for their in vitro activity against a large variety of tumor lines [4][5][6]. Recently organotin compounds have been used as reagents in reduction, transmetallation and coupling reactions or as extremely versatile catalysts in organic reactions [7][8][9][10][11][12][13][14]; the generally high selectivity of organotin reagents allows one to save time and to avoid product losses of protectiondeprotection cycles. In industry, organotin compounds are utilized for esterification and transesterification reactions, for silicone curing, for the preparation of polyurethanes [15], but the stabilization of poly(vinyl chloride) (PVC) is their largest application so far [16].…”

Activation Parameters of an Organotin Catalyzed Alcohol-Isocyanate Reaction

“…Variable fractional orders were found with respect to catalyst and to alcohol and were interpreted with the help (a) of data related to the ratio of monomeric alcohol in the used solvents [3], which is considered as the most reactive alcohol species towards isocyanate [4], (b) of rate laws derived from a reaction scheme (scheme l) [5][6][7][8] in which the catalysis would mainly proceed through a scarcely active monoalkoxytin(IV) able to form with isocyanate and alcohol and/or solvent molecule(s) a pre-reaction complex. This latter would, in the rate determining step, turn into a N-stannylcarbamate easily alcoholysed to yield urethane and restore the catalytic active species.…”