浸提法脱除聚氨酯合成革中微量DMF过程中扩散系数的测定

Measurement of diffusion coefficient of trace DMF in polyurethane leather during extraction process

采用溶剂浸提法,以去离子水为溶剂,考察了不同温度下微量DMF从聚氨酯合成革(PU革)中脱除过程,采用菲克第二定律对实验数据进行拟合。结果显示,当浸提温度从30～50℃时,扩散系数从4.45×10-10 m2/s升高到8.22×10-10 m2/s,采用Arrhenius方程对扩散速率常数进行拟合,得到PU革中DMF脱除过程的表观活化能约为24.90 kJ/mol,说明在该温度区间内,DMF的扩散过程对温度较敏感。

The de-ionized water was used as solvent to remove trace DMF from polyurethane leather by solvent extraction method. Meanwhile, the mass transfer procedure of DMF during extraction at different temperatures was investigated. According to Fick＇ s second law, the relationship between the concentration of DMF in de-ionized water and extraction time was established. The results of data fitting showed that： increasing the extraction temperature from 30 ℃ to 50 ℃, the diffusion coefficient increased from 4.28^-10m^2/s to 8.22 ^-10m^2/s. Moreover,the apparent activation energy was about 24.8 kJ/mol in Arrhenius function, showing that temperature had a great influence upon the diffusion process of DMF.