作者:Wen Li、AFang Zhang
DOI:10.1007/s11426-010-4136-3
日期:2010.12
A series of second generation of amphiphilic dendronized homopolymers are efficiently synthesized, and their thermoresponsiveness in aqueous solutions and secondary structures in methanol solutions are described. These polymers are constructed in each repeat unit with various generations of hydrophobic 4-aminoproline and hydrophilic oligoethylene glycol (OEG)-based dendrons, and their over-all hydrophilicity is tuned by varying these dendron generations. Polymers with or without the first generation of proline dendron show good water solubility at room temperature, but exhibit typical thermoresponsive behaviors at elevated temperatures as characterized by turbidity measurements using UV-vis spectroscopy, while the polymer with the secondary generation of proline dendron is not soluble in water. All polymers show ordered secondary structures as evidenced by the optical rotation and circular dichroism experiments. Finally, assembly of these amphiphilic homopolymers into porous films via breath figure (BF) technique is described, and polymer structures are found to show significant influence on the morphology of porous film.
一系列第二代两亲性树枝化均聚物的合成效率很高,并且描述了它们在水溶液中的热响应性和甲醇溶液中的二级结构。这些聚合物在每个重复单元中构建了不同代数的疏水性4-氨基脯氨酸和亲水性聚氧乙烯甘油(OEG)基树枝状物,并通过改变这些树枝状物的代数来调节它们的整体亲水性。含有或不含第一代脯氨酸树枝状物的聚合物在室温下表现出良好的水溶性,但在升温时表现出典型的热响应行为,这是通过紫外-可见光谱法测定浊度来表征的,而含有第二代脯氨酸树枝状物的聚合物在水中不溶。所有聚合物都显示出有序的二级结构,光学旋转和圆二色实验证明了这一点。最后,描述了这些两亲性均聚物通过呼吸图案(BF)技术组装成多孔膜,并且发现聚合物结构对多孔膜的形态有显著影响。