The synthesis and application of multifunctional diazirine-containing polymers for on-demand cross-linking of unfunctionalized commodity polymers through C–H bond insertion is demonstrated. While small-molecule diazirine cross-linkers have seen important applications such as plastic compatibilization and photopatterning, the high degree of functionalization of polymer-based diazirine cross-linkers offers promise for enhanced compatibility based on polymer blending and increased efficiency due to controllable multivalency. As a demonstrative example, unfunctionalized linear poly(n-butyl acrylate) (PnBA) can be cross-linked using various polymeric cross-linkers with diazirine contents as low as 0.8 wt % in 1 min under photochemical conditions. With gel fractions up to 95%, tunable rheological behavior is observed with increasing cross-linker loadings, consistent with a transition from entangled branched polymers to a cross-linked network. Moreover, the synthetic stability of the diazirine units can be exploited to prepare diazirine-containing polymers based on a variety of different backbones, from vinyl copolymers to poly(dimethylsiloxane) (PDMS), which allows successful photopatterning using a commercial 3D printer.

中文翻译：

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使用含二嗪的聚合物通过非功能化商品材料的 C-H 键插入进行高效交联


展示了多功能含二氮嗪的聚合物的合成和应用，用于通过 C-H 键插入对非官能化商品聚合物进行按需交联。虽然小分子二氮嗪交联剂已经看到了塑料相容和光图案化等重要应用，但基于聚合物的二氮嗪交联剂的高度官能化为基于聚合物共混的增强相容性提供了前景，并且由于可控的多价性而提高了效率。作为一个示范性示例，在光化学条件下，可以使用各种聚合物交联剂使用非功能化线性聚丙烯酸正丁酯）（PN BA），二嗪含量低至 0.8 wt % 在 1 分钟内进行交联。当凝胶分数高达 95% 时，随着交联剂负载量的增加，观察到可调的流变行为，这与从缠结支链聚合物到交联网络的转变一致。此外，可以利用二氮嗪单元的合成稳定性来制备基于各种不同主链的含二氮嗪的聚合物，从乙烯基共聚物到聚二甲基硅氧烷 （PDMS），这允许使用商用 3D 打印机成功进行光图案化。