聚合物反胶团萃取氨基酸的研究

利用德国BASF公司生产的Pluronic型和PluronicR型两类嵌段聚合物制备聚合反应胶团萃取氨基酸（L－苯丙氨酸和L－异亮氨酸）， 聚合物反胶团对氨基酸的萃取平衡特性，实验表明，聚合物反胶团对氨基酸的萃取平衡时间与纯有机溶剂的物理萃取相比差别很小，溶质在反胶团外壳部分与其内部水池间的平衡分配系数K都普遍较大，另外，当氨基酸水溶液的PH值接近等电点时，反胶团萃取达到最佳效果。通过理论分析得到如下推断，聚合物反胶团对两亲性氨基酸的增溶主要在基外壳部分，很可能是包裹在聚氧丙烯外壳内或缠绕在聚氧丙烯链之间，亲油作用和氢键作用是聚合物反胶团萃取的主要推动力。

Extraction of Amino Acids by Polymeric Reverse Micelles

Polymeric reverse micelles were formed with polyoxyalkylene block copolymers as surfactant and 1- octanol as cosolvent in the polyoxyalkylene block copolymers/1-octanol/ p-xylene system. The polyoxyalkylene block copolymers consist of hydrophilic poly(ethylene oxide)(PEO) and hydrophobic poly(propylene oxide)(PPO). Two types of copolymers, PEO-PPO-PEO-type and PPO-PEO-PPO-type triblock copolymers were used. Our present interests are focused on the separation of amino acids by the polymeric reverse micelle solutions. Extraction equilibrium partition of amino acids between polymeric reversed micelle solutions and water was investigated to study the extraction behaviors. The copolymer type and aqueous phase pH affects the extraction process. A model for solute solubilization by the polymeric reverse micelles was proposed. The model of polymeric reversed micelles to solubilize amino acid is most probably as follows: Amino acid is surrounded in the poly(propylene oxide) hydrophobic coronas or twined round by the poly(propylene oxide) chains. The driving force for this process is mainly due to hydrophobic interaction and hydrogen bonding interaction.