分散染料对PHA纤维的染色动力学和热力学研究

Kinetics and thermodynamics of disperse dyed PHA fibers

研究了分散蓝79对聚羟基脂肪酸酯的染色动力学和热力学。试验结果表明,分散蓝79上染PHA纤维的过程符合准二级动力学模型,随着温度的升高,上染速率增加,扩散系数增大,半染时间明显缩短;分散染料对PHA纤维的吸附模型属于能斯特型,染色温度越高,分散蓝79对PHA纤维的亲和力降低,上染PHA纤维的染色熵为-6.02 J/(mol·K),染色热为-21.31 k J/mol,2者都为负值,说明染色过程为自发放热过程。

Dyeing kinetics and thermodynamics of polyhydroxyalkanoates with Disperse Blue 79 were studied. The results showed that Disperse Blue 79 dyed PHA fibers accorded with pseudo-second order kinet- ic model. The dyeing rate increased with the temperature rising, the diffusion coefficient increased and half-dye- ing time significantly decreased. The adsorption model of disperse dye on PHA fibers belongs to Nernst type model. The higher the dyeing temperature, the lower the affinity of Disperse Blue 79 to PHA fiber. The dyeing entropy of Disperse Blue 79 to PHA fiber was -6.02 J/（mol. K）, and heat of dyeing was -21.31 kJ/mol. Both of them were negative, indicating the dyeing process was spontaneous exothermic process.