对苯二甲酸和对羧基苯甲醛在醋酸水溶液中的溶解度

Solubilities of terephthalic acid and 1,4-carboxybenzaldehyde in binary solvent mixture of acetic acid and water

采用平衡法,在0～100%、40%～100%(质量)醋酸的水溶液中和420～505K温度下,分别测定了对苯二甲酸和对羧基苯甲醛的溶解度。在实验温度范围内,当醋酸浓度由70%增加到100%时,对苯二甲酸的溶解度逐渐降低。当温度高于470K时,对苯二甲酸的溶解性随温度升高而急速上升,其中在70%醋酸条件下,对苯二甲酸的溶解度对温度变化最敏感。在水中对苯二甲酸呈现出与醋酸的水溶液不同的溶解特性,温度低于470K时,对苯二甲酸溶解度小于含醋酸的水溶液溶解度,温度高于470K时,对苯二甲酸溶解度随温度升高而显著提高。当醋酸浓度由40%增加到100%时,对羧基苯甲醛的溶解度逐渐增加,对羧基苯甲醛的溶解度对温度变化不敏感。最后,用修正的Apelblat方程对对苯二甲酸和对羧基苯甲醛在醋酸水溶液中所有实验数据分别进行了关联,关联式计算值与实验值吻合良好。

Using the static analytical method,the solubilities of terephthalic acid and 1,4-carboxybenzaldehyde in binary solvent mixtures of acetic acid and water were measured.The experimental temperature ranged from 420 K to 505 K,and the mass fraction of acetic acid in the solvent mixtures ranged from 0 to 100% for terephthalic acid and from 40% to 100% for 1,4-carboxybenzaldehyde.It is shown that as the mass fraction of acetic acid increases from 70% to 100%,the solubility of terephthalic acid reduces gradually within the temperature range.Above 470 K,the solubility of terephthalic acid increases rapidly with temperature,and at 70% mass fraction of acetic acid the solubility is most sensitive to temperature.The solubility of terephthalic acid in water shows different characteristics from that in binary solvent mixtures of acetic acid and water.Below 470 K,the solubility of terephthalic acid is less than that in the aqueous acetic acid solution.When the mass fraction of acetic acid increases from 40% to 100%,the solubility of 1,4-carboxybenzaldehyde increases gradually,but it is not sensitive to temperature.All solubility data of terephthalic acid and 1,4-carboxybenzaldehyde are correlated by modified Apelblat equation,which is in good agreement with experimental data.