双聚己内酯封端苯胺三聚体三嵌段聚合物的合成与研究

以双氨基封端的苯胺三聚体为引发剂,辛酸亚锡为催化剂,在无水甲苯溶液中引发ε-己内酯(ε-CL)开环聚合,得到了分子量约为5900的双聚己内酯封端苯胺三聚体ABA型三嵌段聚合物,并通过核磁、红外、紫外、循环伏安以及热分析等手段对聚合物进行了结构与性能的研究.所得的三嵌段聚合物在有机溶剂中具有较好的溶解性,相比于双氨封端的苯胺三聚体具有更好的热稳定性和电化学稳定性,特别地,所得聚合物对溶液pH值的变化响应范围更宽、更灵敏.

SYNTHESIS AND CHARACTERIZATION OF A DOUBLE POLYESTER CAPPED ANILINE TRIMER ABA BLOCK POLYMER

An ABA block polymer,double polyester capped aniline trimer was synthesized by the reaction of double amino-capped aniline trimer and ε-caprolactone with stannous octoate as catalyst, via ring-opening polymerization in anhydrous toluene solution. The molecular weight of the obtained polymer was ca. 5.9 × 10~3, calculated through ~1H-NMR,very close to the data collected by gel permeation chromatography (GPC;M_n = 5. 0 x 10~3 ,M_w=5.8 × 10~3 ,DMF as solvent). The structure of the polymer was characterized and verified by H-NMR, FT-IR, UV-Vis, cyclic voltammetry (CV) and GPC. The polymer obtained has good solubility in common organic solvents. Both thermostability and electrostability are enhanced, compared to aniline trimer. Especially, the polymer's sensibility to pH value is superior to the standalone aniline trimer. The color of the polymer's solution can be changed from violet to cyanic (from pH = 7 to pH = 5). When the pH value is adjusted from 7 to 8, the solution color is bleached greatly. However, the standalone aniline trimer responds only to acid solution, with the color from royal purple to turquoise. The enhancement of both stability and sensibility gives the polymer more opportunity to be used as sensor materials.