Science Record

SCIENCE RECORD

New Ser. Vol. III, No. 1, 1959

CHEMISTRY

MECHANISM OF HYDROGEN-ION CATALYSIS IN ESTERIFICATION* IV. A STUDY ON THE KINETICS OF ESTERIFICATION REACTIONS BETWEEN SEBACIC ACID AND NORMALOR ISO-OCTYL ALCOHOL

Tane Av-cuin** (fE#UE), Yuo Kuo-sur G@EIFS), ZHenc Ruen-KUN (#64238) anp Gin Yune-pa (#234) (Institute of Applied Chemistry, Academia Sinica, Changchun)

Normal-octyl sebacate and iso-octyl sebacate are two important plasticizers in the modern plastic industry. The purpose of this report is to indicate the probably best conditions for preparations of the above-mentioned two important. plasticizers from the viewpoint of kinetic studies, and is also to examine the mechanism of hydrogen ion catalysis in esterification suggested by two members of the authors!" -

The experimental procedures of this report are the same as those of our first report“!, When sebacic acid and normal octyl alcohol or iso-octyl alcohol in equivalent quantity ratio react at different temperatures in the presence or absence of the foreign acid, the experimental results of the esterification reactions are treated respectively according to the following kinetic equations:

(1/1—p)?? — 1 = 3/2K C32, (1) 1/1—p — 1 = Ky Cu Cor, (2) where p is the extent of the reaction, K = eae ; Co, the initial concentration

of the carboxyl group of sebacic acid in equivalents per kilogram; and Cy, a constant, represents the concentration of hydrogen ion derived from the foreign acid.

EXPERIMENTAL RESULTS The results of the esterification reactions between an equivalent quantity

ratio of sebacic acid and normal-octyl alcohol, and between an equivalent

*Received Nov, 3, 1958. **Member of Academia Sinica,