Simonova Maria, Ivanov Ivan, Meleshko Tamara, Kopyshev Alexey, Santer Svetlana, Yakimansky Alexander, Filippov Alexander
Institute of Macromolecular Compounds of the Russian Academy of Sciences, Bolshoy Pr. 31, 199004 Saint Petersburg, Russia.
Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany.
Polymers (Basel). 2020 Dec 5;12(12):2922. doi: 10.3390/polym12122922.
Three-component molecular brushes with a polyimide backbone and amphiphilic block copolymer side chains with different contents of the "inner" hydrophilic (poly(methacrylic acid)) and "outer" hydrophobic (poly(methyl methacrylate)) blocks were synthesized and characterized by molecular hydrodynamics and optics methods in solutions of chloroform, dimethylformamide, tetrahydrofuran and ethanol. The peculiarity of the studied polymers is the amphiphilic structure of the grafted chains. The molar masses of the molecular brushes were determined by static and dynamic light scattering in chloroform in which polymers form molecularly disperse solutions. Spontaneous self-assembly of macromolecules was detected in dimethylformamide, tetrahydrofuran and ethanol. The aggregates size depended on the thermodynamic quality of the solvent as well as on the macromolecular architectural parameters. In dimethylformamide and tetrahydrofuran, the distribution of hydrodynamic radii of aggregates was bimodal, while in ethanol, it was unimodal. Moreover, in ethanol, an increase in the poly(methyl methacrylate) content caused a decrease in the hydrodynamic radius of aggregates. A significant difference in the nature of the blocks included in the brushes determines the selectivity of the used solvents, since their thermodynamic quality with respect to the blocks is different. The macromolecules of the studied graft copolymers tend to self-organization in selective solvents with formation of a core-shell structure with an insoluble solvophobic core surrounded by the solvophilic shell of side chains.
合成了具有聚酰亚胺主链以及带有不同含量“内层”亲水性（聚（甲基丙烯酸））和“外层”疏水性（聚（甲基丙烯酸甲酯））嵌段的两亲性嵌段共聚物侧链的三组分分子刷，并通过分子流体力学和光学方法在氯仿、二甲基甲酰胺、四氢呋喃和乙醇溶液中对其进行了表征。所研究聚合物的独特之处在于接枝链的两亲性结构。分子刷的摩尔质量通过聚合物在氯仿中形成分子分散溶液时的静态和动态光散射来测定。在二甲基甲酰胺、四氢呋喃和乙醇中检测到了大分子的自发自组装。聚集体的尺寸取决于溶剂的热力学性质以及大分子的结构参数。在二甲基甲酰胺和四氢呋喃中，聚集体的流体力学半径分布是双峰的，而在乙醇中是单峰的。此外，在乙醇中，聚（甲基丙烯酸甲酯）含量的增加导致聚集体的流体力学半径减小。分子刷中所含嵌段性质的显著差异决定了所用溶剂的选择性，因为它们相对于嵌段的热力学性质不同。所研究的接枝共聚物的大分子倾向于在选择性溶剂中自组装，形成核壳结构，其中不溶性的疏溶剂核被侧链的亲溶剂壳包围。
