Kinetics on cocondensation between phenol and urea through formaldehyde II.
Authors: | Yasunori Yoshida, Bunichiro Tomita, Chung-Yun Hse |
Year: | 1995 |
Type: | Scientific Journal |
Station: | Southern Research Station |
Source: | Mokuzai Gakkaiski, Vol. 41(6): 555-560 |
Abstract
The chemical kinetics of the concurrent reactions of 2,4,6-trimethylolphenol with urea, where o- and p-methylol groups reacted simultaneously with urea, were analyzed on four kinds of catalysts: namely, sulfuric acid, hydrochloric acid, nitric acid, and oxalic acid. The results were summarized as follows:(1) assuming that each reaction follows the second-order reaction, the reactivity ratio (K=ko/kp) of the o- to p-methylol group could be obtained from the kinetic plots of equation [5] within small errors.
The reactivity ratios were determined to be 0.066 to 0.075 by the least-square method for four kinds of acid catalysts.
(3) The reactivity ratio of the pseudo-first-order rate constants obtained by competitive cocondensations under the coexistence of o- and p-methylolphenols with a sulfuric acid catalyst was found to be almost identical with that obtained by the cocncurrent cocondensation of the trimethylolphenol.