Kottisch Veronika, Gentekos Dillon T, Fors Brett P
Cornell University, Ithaca, New York 14853, United States.
ACS Macro Lett. 2016 Jul 19;5(7):796-800. doi: 10.1021/acsmacrolett.6b00392. Epub 2016 Jun 17.
Varying molecular weight distributions (MWDs) have the potential to precisely tune polymer properties, but this approach remains relatively unexplored owing to a lack of synthetic methods that provide control over the exact makeup of a distribution. Herein, we report a simple and highly efficient strategy for addressing this challenge through temporal regulation of initiation in the anionic polymerization of styrene. This method yields unprecedented control over the shape of the polymer MWD and facilitates the synthesis of diblock copolymers with controlled MWD compositions. Importantly, we show that the MWD symmetry has a marked influence on the stiffness of poly(styrene--isoprene) copolymers, which demonstrates that varying MWD shape is an effective method for altering polymer properties.
不同的分子量分布（MWD）有潜力精确调节聚合物性能，但由于缺乏能够控制分布的确切组成的合成方法，这种方法仍相对未被探索。在此，我们报告了一种简单且高效的策略，通过对苯乙烯阴离子聚合引发的时间调控来应对这一挑战。该方法对聚合物MWD的形状产生了前所未有的控制，并促进了具有可控MWD组成的二嵌段共聚物的合成。重要的是，我们表明MWD对称性对聚（苯乙烯 - 异戊二烯）共聚物的刚度有显著影响，这表明改变MWD形状是改变聚合物性能的有效方法。
