Department of Materials Science Engineering, University of Ioannina, University Campus-Dourouti, 45110 Ioannina, Greece.
Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Plank-Str. 1, 21502 Geesthacht, Germany.
Molecules. 2020 Dec 19;25(24):6030. doi: 10.3390/molecules25246030.
To the best of our knowledge, this is the very first time that a thorough study of the synthetic procedures, molecular and thermal characterization, followed by structure/properties relationship for symmetric and non-symmetric second generation (2-G) dendritic terpolymers is reported. Actually, the synthesis of the non-symmetric materials is reported for the first time in the literature. Anionic polymerization enables the synthesis of well-defined polymers that, despite the architecture complexity, absolute control over the average molecular weight, as well as block composition, is achieved. The dendritic type macromolecular architecture affects the microphase separation, because different morphologies are obtained, which do not exhibit long range order, and various defects or dislocations are evident attributed to the increased number of junction points of the final material despite the satisfactory thermal annealing at temperatures above the highest glass transition temperature of all blocks. For comparison reasons, the initial dendrons (miktoarm star terpolymer precursors) which are connected to each other in order to synthesize the final dendritic terpolymers are characterized in solution and in bulk and their self-assembly is also studied. A major conclusion is that specific structures are adopted which depend on the type of the core connection between the ligand and the active sites of the dendrons.
据我们所知,这是首次对对称和非对称第二代(2-G)树枝状三聚体的合成工艺、分子和热特性进行全面研究,并探讨了结构/性能关系。实际上,非对称材料的合成在文献中也是首次报道。阴离子聚合能够合成结构明确的聚合物,尽管具有复杂的结构,但可以实现对平均分子量以及嵌段组成的绝对控制。树枝状大分子结构会影响微相分离,因为可以得到不同的形貌,这些形貌不具有长程有序性,而且由于最终材料的连接点数量增加,会出现各种缺陷或位错,尽管在高于所有嵌段的最高玻璃化转变温度的温度下进行了令人满意的热退火。出于比较的原因,将对连接在一起以合成最终树枝状三聚体的初始树枝(混合臂星状三聚物前体)进行溶液和本体表征,并研究其自组装。一个主要结论是,采用了特定的结构,这取决于配体和树枝状大分子活性位点之间的核心连接类型。