聚胺基甲酸酯之合成及其在木材塗裝與膠合上之應用（I）聚酯化反應之反應動力學探討

Studies on the Synthesis of Polyurethane and its Utilization as Adhesives and Coatings for Wood (1) Reaction Kinetics of Polyesterifications

本研究乃探討己二酸及乙二醇在無催化劑或酸催化劑存在下聚酯化反應之動力學，所得重要結果為：酸與醇之聚酯化反應過程中若無催化劑存在，則其反應初期之酸價降低迅速，但至反應末期其酸價之降低緩慢。升高反應溫度或增加反應時醇對酸之莫耳比（MR）均可使其反應速率增快。其反應對酸而言為二次反應，反應活化能約為17.0～19.5 kcal/mole。催化劑之存在對於聚酯化反應初期之反應速率有極明顯之促進作用，但對其末期之反應幾無作用。 The react ion kinetics of polyesterifications of ethylene glycol and adipic acid under none acid-catalyzed or under acid-catalyzed were investigated in this study. The results are summarized as follows. Polyesterification in the absence of a foreign acid, the acid value decreased fast at the beginning of the reaction and then became slower in the later retention time. The higher reaction temperature or great alcohol to acid molar ratio, the faster reaction rate could be obtained. The reaction rate was proportional to the second order of the carboxyl group concentration. The activation energies of the uncatalyzed polyesterification were about 17.0~19.5 kcal/mole. The catalyst would accelerate the rate of polyesterification in early stage but not in the late stage.

The react ion kinetics of polyesterifications of ethylene glycol and adipic acid under none acid-catalyzed or under acid-catalyzed were investigated in this study. The results are summarized as follows. Polyesterification in the absence of a foreign acid, the acid value decreased fast at the beginning of the reaction and then became slower in the later retention time. The higher reaction temperature or great alcohol to acid molar ratio, the faster reaction rate could be obtained. The reaction rate was proportional to the second order of the carboxyl group concentration. The activation energies of the uncatalyzed polyesterification were about 17.0~19.5 kcal/mole. The catalyst would accelerate the rate of polyesterification in early stage but not in the late stage.