Covalent functionalization of hexagonal boron nitride nanosheets (BNNSs) is very challenging because of their surface inactivity. In this work, a simple reductive activation method is reported to covalently decorate BNNSs with polymers. BNNSs are initially negatively charged through effective reductive treatment and subsequently reacted with bromine‐terminated poly(methyl methacrylate) chains bearing different molecular weights to obtain a series of polymer‐grafted BNNSs, which greatly enhances their compatibility and dispersibility within acetone. With the increase of the molecular weight, grafting ratio and the density of grafted chains on BNNS surfaces show decreasing trends due to steric hinderance. Addition of functionalized BNNSs at a low filler content significantly improves reinforcement performance for polymer composites. The functionalization via the reduction treatment represents a novel and versatile route to anchor a range of functionalized species to manipulate surface chemistry toward the production of functional BNNSs for broad applications.

中文翻译：

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氮化硼纳米片通过还原化学接枝聚合物及其对聚合物复合材料的增强作用

六方氮化硼纳米片（BNNSs）的共价官能化非常具有挑战性，因为它们的表面不活泼。在这项工作中，据报道一种简单的还原活化方法可以用聚合物共价修饰BNNS。BNNS最初通过有效的还原处理带负电荷，然后与具有不同分子量的溴封端的聚甲基丙烯酸甲酯链反应，获得了一系列聚合物接枝的BNNS，这大大增强了它们在丙酮中的相容性和分散性。随着分子量的增加，由于位阻，BNNS表面的接枝率和接枝链密度呈现下降趋势。以低填料含量添加官能化BNNS可以显着改善聚合物复合材料的增强性能。