ผลของความหนาแน่นตำแหน่งกรดของแอมเบอลิสต์เรซินและซีโอไลต์ต่อเอสเทอริฟิเคชันของกรดไดคาร์บอกซิลิกกับ 2–เอทิล–1–เฮกซานอล / ชวลินทร์ หมุดสุวรรณ์ = Effects of acid site density of amberlyst resin and zeolites on esterification of dicarboxylic acids with 2-ethyl-1-hexanol / Chawalin Mudsuwan
In this research, effects of acid site density on activity and deactivation of amberlyst resin and zeolite in esterification of dicarboxylic acids (adipic acid and azelaic acid) with 2–ethyl–1–hexanol have been investigated. The acid site density of Amberlyst 15 decreased with the increasing of exchanging time and NaCl concentration. It was found that diester yield and diester selectivity increased when the acid site density of the catalyst was increased. Amberlyst 15 with the acid site density of 3.49 and 4.7 mmol g-1 gave the highest initial rate and diester yield in esterification of adipic acid and azelaic acid, respectively. The ester hydrolysis, as reverse reaction, was increased due to the enhancement of acid site density. Study on effects of particle size of the catalyst indicated that the diffusion limitation was absent. Zeolite beta can not catalyze the esterification because of small pore size. Moreover the increasing of acid site density enhanced the deactivation of catalyst by strong adsorption of larger organic compound.