温敏荧光聚合物(PNIPAM-co-AN)的设计合成与性能研究

Design,Synthesis and Properties of Temperature-Sensitive Fluorescent Polymer(PNIPAM-co-AN)

以N-异丙基丙烯酰胺和丙烯酸甲酯(MA)为单体,采用自由基聚合方法,合成温敏聚合物,然后与水合肼反应,再接枝三苯基咪唑荧光团合成温敏荧光聚合物(记为PNIPAM-co-AN),采用红外光谱、热重分析和凝胶渗透色谱进行表征;考察了MA投料比对聚合物相对分子质量及其分布的影响;通过目测法和紫外法分别测定了聚合物的最低临界溶解温度(LCST)。研究表明:随着MA含量的增加,PNIPAM-co-AN的LCST会降低。当pH>7时,PNIPAM-co-AN不存在LCST;当pH<7时,随着酸性的增强,PNIPAM-co-AN的LCST会减小。

The thermosensitive fluorescent polymer poly(N-isopropylacrylamide-co-propenyl-4-4,5-diphenyl-1h-imidazol-2-yl)benzoylhydrazone(labeled PNIPAM-co-AN)was synthesized by free radical polymerization using N-isopropylacrylamide and methyl acrylate(MA)and then reacted with hydrazine hydrate,as well as grafted with triphenylimidazolyl fluorophones.Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TG)and gel permeation chromatography(GPC)were employed for characterization.The effect of hydrophobic monomer MA feeding ratio on the molecular weight and distribution of copolymer was investigated.The lowest critical solution temperature(LCST)of copolymer was determined by visual method and UV-vis spectroscopy.The research results show that with the increase of MA content of the polymer,the LCST of PNIPAM-co-AN decreased.When pH>7,PNIPAM-co-AN has no LCST.With the increase of acidity(pH<7),LCST of PNIPAM-co-AN decreased.