Effect of Substituents and Solvents on Phenol-Isocyanate Urethane Reaction

Abstract:

Article Preview

In this study, the urethane reaction of several phenols with isocyanate was monitored with in-situ FT-IR. Reaction rate constants were calculated out to investigate the effect of substituents in phenols, as well as the polarity of different solvents. It showed that the polarity of solvents largely affected the reaction rate even without catalyst. The reactivity increased in the following order: Xylene < 1,4-Dioxane < Cyclohexanone. Furthermore, an electron-withdrawing substituent in phenols increased the reactivity of hydroxyl with isocyanate. The reason may be that the H-O bond in phenols could be easily polarized under the influence of electron-withdrawing substituent, where the hydrogen atom was more likely to attack the nitrogen atom of -NCO, thus the nucleophilic addition happened easier.

Info:

Periodical:

Advanced Materials Research (Volumes 150-151)

Edited by:

Jinglong Bu, Zhengyi Jiang and Sihai Jiao

Pages:

23-26

DOI:

10.4028/www.scientific.net/AMR.150-151.23

Citation:

P. F. Yang et al., "Effect of Substituents and Solvents on Phenol-Isocyanate Urethane Reaction", Advanced Materials Research, Vols. 150-151, pp. 23-26, 2011

Online since:

October 2010

Export:

Price:

$35.00

In order to see related information, you need to Login.

In order to see related information, you need to Login.