Polymer chemistry offers exciting opportunities to tailor the properties of soft materials through control of the composition of the polymers and their interaction with each other, additives, and surfaces. Ongoing advances in the synthesis of polymeric materials demonstrate the drive for materials with tailored properties for enhanced performance in the next generation of materials and devices. One class of small molecules that can serve as monomers in chain growth polymerization are cumulated double bonds of the general form X═Y═Z. The three most common classes of these molecules are isocyanates (N═C═O), allenes (C═C═C), and ketenes (C═C═O), each of which has been explored as monomers under a variety of conditions. The orthogonality of the two pi bonds of the cumulated double bonds (i.e., lack of conjugation) enables the formation of different polymer backbones from a single monomer, provided the regioreactivity is controlled. This Viewpoint outlines the use of these three cumulated double bonds as monomers, illustrating success and current limitations to established polymerization methods. We then provide an outlook to the future of cumulated double bonds as monomers for the generation of tailored polymer compositions.

中文翻译：

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累积键的聚合：作为单体的异氰酸酯、丙二烯和烯酮

聚合物化学通过控制聚合物的组成及其相互、添加剂和表面的相互作用，为定制软材料的性能提供了令人兴奋的机会。聚合物材料合成的持续进展证明了对具有定制特性的材料的推动，以提高下一代材料和设备的性能。一类可在链增长聚合中用作单体的小分子是通式 X=Y=Z 的累积双键。这些分子中最常见的三类是异氰酸酯 (N=C=O)、丙二烯 (C=C=C) 和烯酮 (C=C=O)，它们中的每一种都已在各种条件下作为单体进行了探索. 累积双键的两个 pi 键的正交性（即，缺乏共轭）能够从单一单体形成不同的聚合物主链，前提是控制区域反应性。该观点概述了这三个累积双键作为单体的用途，说明了已建立的聚合方法的成功和当前的局限性。然后，我们展望了累积双键作为单体用于生成定制聚合物组合物的未来。