聚(N-异丙基丙烯酰胺)-环糊精星形聚合物的RAFT聚合合成与表征

摘要

基于聚(N-异丙基丙烯酰胺)(PNIPAm)的热敏性与环糊精(CD)的超分子包合性,用可逆加成-断链转移(RAFT)反应,由“先臂法”合成出了SSPNIPAm-CD星形聚合物.用FTIR、1 H-NMR、SEC/MALLS、DSC、荧光光谱与电位滴定对星形聚合物及其前驱体的结构与性能进行了表征.DSC测定表明,星形聚合物的形成与环糊精的引入均会引起其玻璃化转变温度(Tg)的升高;也使其在水溶液中的最低临界溶解温度(LCST)升高,但发生相变过程的热效应△H减小.用8-苯胺基-1-萘磺酸铵盐(ANS)作为荧光探针,研究表明星影聚合物具有超分子包合性.%Star-shaped polymer based on poly(N-isopropylacrylamide) (PNIPAm) and cyclodextrin (CD) was synthesized through arm-first approach via RAFT polymerization. The structure and properties of the star-shaped polymer and its precursors were characterized by means of FTIR,1H-NMR, SEC/MALLS, DSC, potentiometric titra-tion and fluorescence measuremecnts. The results from DSC measurements indicate that both the formation of the star-shaped polymer and the incorporation of CD onto the star-shaped polymer could lead to an increase in glass transition temperature (Tg) of the polymer. DSC measurements also show that lower critical solution temperature (LCST) of the star-shaped polymer in aqueous solution shifts to higher temperature region, but the AH of the phase separation for the star-shaped polymer is lower than that of its precursors. Using 8-anilino-1-naphthalenesulfonic acid ammonium salt hydrate (ANS) as a guest molecule, the supramolecular inclusion of the star-shaped polymer was investigated by fluorescence spectra The results indicate that the SSPNIPAm-CD can include ANS molecule.