光敏感双亲性梳状SMA聚合物的合成及其胶束化

以含香豆素型苯乙烯类光敏单体(coumarin-containing styrene monomer, CS)与苯乙烯(St)、马来酸酐(MA)为反应单体, 以偶氮二异丁腈(AIBN)为引发剂制备了光敏感三元苯乙烯-马来酸酐共聚物(SMA)双亲交替聚合物P(St/CS-alt-MA), 再利用羧酸酐基元与正辛胺的室温胺解反应获得光敏感双亲性梳状聚合物P(St/CS-alt-MAA8). 用傅立叶变换红外光谱(FTIR)、凝胶渗透色谱(GPC)、1H核磁共振(1H-NMR)等对该双亲梳状聚合物进行结构表征. 通过香豆素基元的光二聚作用, 使梳状聚合物溶解在DMSO中进行光照预交联; 非交联与预交联聚合物分别在选择性溶剂中自组装形成胶束; 利用羧酸基元与NaOH的离子化作用改变聚合物胶束的亲疏水性质. 动态激光光散射(DLS)与芘荧光探针实验表明预交联聚合物胶束较非交联胶束粒径大, 负载芘的能力强; 离子化作用使聚合物胶束解离重组成粒径更小的胶束, 但预交联胶束较非交联胶束小, 离子化后胶束疏水微区更加紧密, 负载芘的能力也增大.

Synthesis and Micellization of Photosensitive Amphiphilic Comblike SMA Polymer

Coumarin-containing styrene monomer (CS) was designed and synthesized, which could be used together with styrene (St) and maleic anhydride (MA) to synthesize the photosensitive amphiphilic alternating SMA terpolymer poly(styrene/coumarin-containing styrene-alt-maleic anhydride) (P(St/CS-alt-MA)) via free radical copolymerization. Then a new photosensitive amphiphilic comblike terpolymer (P(St/CS-alt-MAA8)) with long alkyl side chains was obtained by the functional amidolysis reaction between succinic anhydride unit and octylamine, and its structure was characterized by gel permeation in chromatography (GPC), Fourier transforminfrared spectroscopy (FTIR), and 1Hnuclear magnetic resonance (1HNMR). It was found that the comblike polymer could aggregate by the photo-dimerization of the coumarin pendants under UV irradiation (>300 nm), and formnanoscale micelles by self-assembly in selective solvent. The micelles could be modified by the ionization of carboxylic acid groups with NaOH. Pyrene loading experiment and dynamic laser scattering (DLS) showed that the micelle diameter and the loading capacity of precrosslinked polymer were bigger than those of non-crosslinked polymer. Micelles reformed after ionization, which made the hydrophobic area denser and the micelle diameter smaller, while the loading capacity also increased.