Abstract Radical ring-opening polymerisation (RROP) of cyclic ketene acetals (CKAs) has gained momentum as it yields polyesters as biodegradable polymers from a radical polymerisation. In order to advance the polymerisation, some of its major limitations were addressed in the research presented, focussing on the four mainly used CKAs in modern research on RROP. Monomer synthesis has been updated towards a cobalt/TMSCl-based system that was performed reliably on several monomers at room temperature. Calculations using the density functional theory (DFT) revealed that the ring-opening step is energetically hampered in comparison to a ring-retaining reaction, which explained the challenges faced to promote the ring-opening reaction. Higher molecular weights up to four times the values reached by thermally initiated polymerisation were obtained by exploiting UV light and ultrasound as alternative methods to facilitate the polymerisation. The reaction procedure also influenced thermal properties of the polymers, which in turn affected the enzymatic degradation of nanoparticles based on those polymers. Altogether, the present study offers a holistic update to enhance the RROP of CKAs.

中文翻译：

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环烯酮缩醛自由基开环聚合从合成到降解的更新

摘要 环烯酮缩醛 (CKAs) 的自由基开环聚合 (RROP) 获得了动力，因为它通过自由基聚合产生聚酯作为可生物降解的聚合物。为了推进聚合，其一些主要局限性在所呈现的研究中得到解决，重点是现代 RROP 研究中主要使用的四种 CKA。单体合成已更新为基于钴/TMSCl 的系统，该系统在室温下对几种单体进行了可靠的合成。使用密度泛函理论 (DFT) 的计算表明，与保环反应相比，开环步骤在能量上受到阻碍，这解释了促进开环反应所面临的挑战。通过利用紫外线和超声波作为促进聚合的替代方法，获得了高达四倍于热引发聚合所达到的值的更高分子量。反应过程还影响了聚合物的热性能，进而影响了基于这些聚合物的纳米颗粒的酶降解。总之，本研究提供了一个整体更新，以提高 CKA 的 RROP。