Polylactide and polycaprolactone are both biodegradable polymers produced through metal‐catalyzed ring‐opening polymerization. For a truly sustainable lifecycle of these polymers it is essential to replace the industrially used cytotoxic catalyst tin(II) bis(2‐ethylhexanoate) [Sn(Oct)₂] with non‐toxic alternatives. Here, we report the fastest known robust catalyst in the polymerization of lactide and ϵ‐caprolactone. This zinc guanidine catalyst can polymerize non‐purified technical rac‐lactide and ϵ‐caprolactone in the melt at different [M]/[I] ratios with fast rate constants, high molar masses, and high yields in a short time, leading to colorless, transparent polymer. Moreover, we report that polylactide and polycaprolactone produced by zinc‐guanidine complexes have favorably high crystallinities. In fact, the obtained polylactide shows a more robust degradation profile than its Sn(Oct)₂‐catalysed equivalent due to a higher degree of crystallinity.

中文翻译：

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下一代高结晶度，可生物降解聚酯的双胍双锌聚合催化剂。

聚丙交酯和聚己内酯都是通过金属催化的开环聚合反应生产的可生物降解的聚合物。对于这些聚合物的真正可持续的生命周期，必须用无毒替代品代替工业上使用的细胞毒性催化剂双（2-乙基己酸锡（II）双（2-乙基己酸）₂ [Sn（Oct）₂ ] ）。在这里，我们报告了丙交酯和ε-己内酯聚合反应中已知最快的耐用催化剂。此锌胍催化剂可以聚合的非纯化技术外消旋丙交酯和ε-己内酯在熔体中以不同的[M] / [I]比例变化，具有快速的速率常数，高的摩尔质量和短时间内的高收率，从而形成无色透明的聚合物。此外，我们报道锌-胍络合物产生的聚丙交酯和聚己内酯具有良好的高结晶度。实际上，由于较高的结晶度，所获得的聚丙交酯比其Sn（Oct）₂催化的同等物表现出更强的降解特性。