Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore.
ACS Macro Lett. 2021 May 18;10(5):584-590. doi: 10.1021/acsmacrolett.1c00179. Epub 2021 Apr 23.
The molecular weight distribution of polymer, termed dispersity (), is a fundamental parameter that determines polymer properties. Sodium azide (NaN) functions as a catalyst in organocatalyzed living radical polymerization when the reaction medium is nonpolar. In contrast, NaN can act as a nucleophile when the reaction medium is polar. In this paper, we report an efficient approach to dispersity control by exploiting the dual functions of NaN under the varied solvent polarity. Simultaneous polymerization and chain-end substitution allowed us to tune the values of various polymethacrylates and poly(butyl acrylate). Notably, the value could be tuned to a wide range approximately from 1.2 to 2.0 for polymethacrylates and to 3.8 for poly(butyl acrylate). This approach afforded polymer brushes on surfaces with tailored values. An interesting finding was that the polymer brushes exhibited a unique interaction with external molecules, depending on the value.
聚合物的分子量分布，称为分散度（），是决定聚合物性质的基本参数。当反应介质为非极性时，叠氮化钠（NaN）在有机催化的活性自由基聚合中作为催化剂发挥作用。相比之下，当反应介质为极性时，NaN 可以作为亲核试剂。在本文中，我们报告了一种通过利用 NaN 在不同溶剂极性下的双重功能来控制分散度的有效方法。同时聚合和链末端取代使我们能够调节各种聚甲基丙烯酸酯和聚（丙烯酸丁酯）的 值。值得注意的是，聚甲基丙烯酸酯的值可以在大约 1.2 到 2.0 的较宽范围内进行调节，而聚（丙烯酸丁酯）的值可以调节到 3.8。该方法可以在表面上获得具有特定 值的聚合物刷。一个有趣的发现是，聚合物刷表现出与外部分子的独特相互作用，这取决于 值。
