Polyvinylpyridine‐Grafted Block Copolymers by an Iterative All‐Anionic Polymerization Strategy
Polyvinylpyridine‐Grafted Block Copolymers by an Iterative All‐Anionic Polymerization Strategy
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DOI：
10.1002/macp.201700187
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发表时间：
2018
影响因子：
2.5
通讯作者：
Michael Appold;Christian Rüttiger;B. Kuttich;B. Stühn;M. Gallei
中科院分区：
文献类型：
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作者：
Michael Appold;Christian Rüttiger;B. Kuttich;B. Stühn;M. Gallei
功能嵌段共聚物是一种高度相关的材料平台，在纳米光刻，药物输送和分离技术领域具有许多潜在的应用。本文通过阴离子接枝-拓扑聚合策略合成了由聚苯乙烯-嵌段-聚异戊二烯（PS - b - PI）骨架组成的聚（2 -乙烯基吡啶）(P2VP) -接枝二嵌段共聚物。分子量分别为1.1、3.6和9.9 kDa的P2VP宏观阴离子接枝到分子量为37 mol% 1,2 -聚异戊二烯的PS - b - PI嵌段共聚物上。在接枝策略之前，PS - b - PI进行了铂催化的硅氢化反应，以引入氯硅烷基团。Si - Cl基团有利于P2VP宏观阴离子与PS - b - PI的亲核反应，生成的接枝嵌段共聚物的最终P2VP体积分数分别为73,87和93%。通过动态光散射实验和透射电子显微镜（TEM）研究了P2VP -接枝嵌段共聚物在极性溶剂和水中（吡啶部分质子化后）的胶束化。作为这项工作的重点，注意到引入P2VP片段对体态微相分离的影响是巨大的。TEM测量和小角度X射线散射实验证实了这一点，表明在纳米尺度上对形貌有很好的控制。
Functional block copolymers are a highly relevant material platform for many potential applications in fields of nanolithography, drug delivery, and separation technologies. Here, poly(2‐vinylpyridine) (P2VP)‐grafted diblock copolymers consisting of polystyrene‐block‐polyisoprene (PS‐b‐PI) backbone are synthesized via an iterative anionicgrafting‐topolymerization strategy. P2VP macro anions having molar masses of 1.1, 3.6, and 9.9 kDa are grafted to PS‐b‐PI block copolymers featuring 37 mol% 1,2‐polyisoprene moieties. Prior to thegrafting‐tostrategy, the PS‐b‐PI is subjected to platinum‐catalyzed hydrosilylation reaction for the introduction of chlorosilane groups. The SiCl moieties are advantageously used for nucleophilic reaction of the P2VP macro anions with PS‐b‐PI yielding grafted block copolymers having a final P2VP volume fraction of 73, 87, and 93 vol%. Micellization of the P2VP‐grafted block copolymers in polar solvents and in water (after protonation of the pyridine moieties) is studied by dynamic light scattering experiments and transmission electron microscopy (TEM). As a focus of this work, the influence on microphase separation in the bulk state is noted to be tremendously influenced by introducing P2VP segments. This is confirmed by TEM measurements and small angle X‐ray scattering experiments, which reveal a good control over morphologies at the nanometer length scale.