阴离子型含氟两亲接枝共聚物的合成及其胶束化行为研究

SYNTHESIS AND MICELLIZATION BEHAVIOR OF ANIONIC FLUORINE-CONTAINING AMPHIPHILIC GRAFT COPOLYMERS

以聚乙二醇甲醚甲基丙烯酸酯(MPEGMA)为大分子单体,甲基丙烯酸六氟丁酯(HFMA)、对苯乙烯磺酸钠(NaSS)为共聚单体,采用大分子单体接枝共聚法,制备了一种阴离子型含氟两亲接枝共聚物P(HFMA-co-NaSS)-g-PEG.利用FTIR、1 H-NMR和19 F-NMR对共聚物的分子结构进行了表征.表面张力法测定了P(HFMA-co-NaSS)-g-PEG的临界胶束浓度(CMC),发现随着PEG支链和阴离子含量的增加,CMC逐渐变大;采用动态光散射法(DLS)研究发现,随着胶束溶液浓度和PEG支链的增加,胶束粒径逐渐增大;荧光光谱法研究了P(HFMA-co-NaSS)-g-PEG自组装胶束与牛血清蛋白(BSA)的相互作用,结果表明阴离子型含氟两亲接枝共聚物可以使BSA的荧光强度减弱,且随着共聚物浓度、含氟链段以及阴离子含量的提高,荧光强度逐渐降低;通过透射电子显微镜(TEM)研究了P(HFMA-co-NaSS)-g-PEG胶束以及P(HFMA-co-NaSS)-g-PEG/BSA聚集体的形貌,结果表明P(HFMA-co-NaSS)-g-PEG在水溶液中可自组装成核壳结构明显的胶束粒子,随着含氟链段的减少,共聚物胶束由树叶状转变成规则的球状结构,同时,发现P(HFMA-co-NaSS)-g-PEG胶束对BSA分子有明显的吸附作用.

A novel series of anionic fluorine-containing amphiphilic graft copolymers P（HFMA-co-NaSS）-g-PEG were synthesized by graft copolymerization of poly（ethylene glycol） methyl ether methacrylate（MPEGMA） macromonomer,2,2,3,4,4,4-hexafluorobutyl methacrylate（HFMA） and sodium 4-vinylbenzenesulfonate（NaSS）.The molecular structures of the amphiphilic graft copolymer were characterized by FTIR,1H-NMR and 19F-NMR.The critical micelle concentration（CMC） of P（HFMA-co-NaSS）-g-PEG was measured by surface tension technique,indicating that the CMC increased gradually with increasing PEG branched chains and anionic contents in the copolymer.The average hydrodynamic diameter and size distribution of micelles were measured by dynamic light scattering（DLS）.The measurement showed that the hydrodynamic diameter increased gradually with increasing the concentration of P（HFMA-co-NaSS）-g-PEG aqueous solution and the content of PEG branched chains in P（HFMA-co-NaSS）-g-PEG.The fluorescence spectrum showed that there was a significant interaction between P（HFMA-co-NaSS）-g-PEG micelles and bovine serum albumin（BSA）.The fluorescence intensity of BSA decreased gradually in P（HFMA-co-NaSS）-g-PEG/BSA aqueous solution with increasing the concentration of P（HFMA-NaSS）-g-PEG aqueous solution,HFMA segments and NaSS contents.Transmission electron microscopy（TEM） was used to investigate P（HFMA-co-NaSS）-g-PEG micelles and the aggregates of P（HFMA-co-NaSS）-g-PEG/BSA,the results showed that P（HFMA-co-NaSS）-g-PEG copolymers could self-assemble into core-shell structure micelles.Besides,with the decrease of HFMA contents in the copolymer,the morphology of P（HFMA-co-NaSS）-g-PEG micelles changed from a leaf-like structure to a spherical one.In particular,when BSA was added,the micelles changed from a tight core-shell structure into a loose vesicle-like structure,and the micelle size and size distribution also increased.TEM micrographs of P（HFMA-co-NaSS）-g-PEG/BSA displayed a visible adsorption phenomenon between P（HFMA-co-NaSS）-g-PEG micelles and BSA,and suggested that P（HFMA-co-NaSS）-g-PEG may have potential applications in loading proteins and other bioactive drugs.