In polyesterification

the action of alcohol as a carrier of H+-ion was supposed to be negligable

in contrast to the result obtained by Tang Au-Ching. A new hypothesis of polyesterification was then suggested.This mechanism can be used to explain some other types of esterification as well. Favourable results were obtained even if p (the percent of the theoretical degree of reaction) is greater than 91%. In the hydrolysis of esters by using strong or weak acid as catalysts

results obtained were found to be better than those obtained by previous authors.