二甲苯甲醛樹脂之研究 第一報 二甲苯異構體與甲醛反應速度之測定

Study on Xylene-Formaldehyde Resin l. Determination of Reaction Rates of Xylene Isomers with Formaldehyde

曹福湧(Fu-Yung Tsao)

《化學》 58年3期 (1969/09) Pp. 46-50

https://doi.org/10.6623/chem.1969010

摘要

二甲苯各異構體對甲醛反應速度不同，間、對、鄰二甲苯及乙苯之反應速度比約爲10：1：1.6：0.4。反應溫度，觸媒硫酸用量；甲醛與二甲苯異構體比率均對反應之快慢有顯著影響。反應溫度每增加15°C反應速度增加一倍以上。間二甲苯與對二甲苯如欲藉與甲醛反應而分離，其適宜條件爲甲醛溶液（36%）125克，硫酸（98%）53.0克，二甲苯異構體53.0克，反應溫度75°C，反應時間6小時。在此情形下，如爲間二甲苯，反應者50克，未反應者3克，而對二甲苯，反應者4克，未反應者49克。

並列摘要

A series of experiments were made on the reaction of xylene isomers with formaldehyde in the presence of H_2SO_4 as catalyst. Reactions were found to proceed in different speeds of which the relative ratio was meta-xylene: para-xylene: ortho-xylene: ethyl benzene=10:1:1.6:0.4. Factors such as temperature, amount of catalyst H_2SO_4 used, ratio of formaldehyde to xylene isomer affected the reaction greatly. An increase of 15℃ doubled the reaction rate. The favorable condition for separating meta- and para- xylene from their mixture by reacting with formaldehyde was formalin (36%) 125 grams, H_2SO_4 (98%) 53 grams, xylene isomer 53 grams, temperature 75°C, and reaction time 6 hrs. Under this condition 50 grams of meta-xylene were converted and 3 grams remained, while only 4 grams of para-xylene reacted, and 49 grams remained.