The increased production of plastics is leading to the accumulation of plastic waste and depletion of limited fossil fuel resources. In this context, we report a strategy to create polymers that can undergo controlled depolymerization by linking renewable feedstocks with siloxane bonds. α,ω-Diesters and α,ω-diols containing siloxane bonds were synthesized from an alkenoic ester derived from castor oil and then polymerized with varied monomers, including related biobased monomers. In addition, cyclic monomers derived from this alkenoic ester and hydrosiloxanes were prepared and cyclized to form a 26-membered macrolactone containing a siloxane unit. Sequential ring-opening polymerization of this macrolactone and lactide afforded an ABA triblock copolymer. This set of polymers containing siloxanes underwent programmed depolymerization into monomers in protic solvents or with hexamethyldisiloxane and an acid catalyst. Monomers afforded by the depolymerization of polyesters containing siloxane linkages were repolymerized to demonstrate circularity in select polymers. Evaluation of the environmental stability of these polymers toward enzymatic degradation showed that they undergo enzymatic hydrolysis by a fungal cutinase from Fusarium solani. Evaluation of soil microbial metabolism of monomers selectively labeled with ¹³C revealed differential metabolism of the main chain and side chain organic groups by soil microbes.

中文翻译：

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来自植物油的聚合物通过硅氧烷键连接进行程序解聚

塑料产量的增加导致塑料废物的积累和有限的化石燃料资源的枯竭。在这种背景下，我们报告了一种策略，通过将可再生原料与硅氧烷键连接来制造可以进行受控解聚的聚合物。含有硅氧烷键的α,ω-二酯和α,ω-二醇是由蓖麻油衍生的烯酸酯合成的，然后与各种单体（包括相关的生物基单体）聚合。此外，制备衍生自该链烯酸酯和氢硅氧烷的环状单体并环化以形成含有硅氧烷单元的26元大环内酯。这种大环内酯和丙交酯的连续开环聚合提供了 ABA 三嵌段共聚物。这组含有硅氧烷的聚合物在质子溶剂中或使用六甲基二硅氧烷和酸催化剂进行程序解聚成单体。将含有硅氧烷键的聚酯解聚得到的单体进行再聚合，以证明所选聚合物的环状性。对这些聚合物对酶降解的环境稳定性的评估表明，它们会被来自茄病镰刀菌的真菌角质酶进行酶水解。对¹³ C选择性标记单体的土壤微生物代谢的评估揭示了土壤微生物对主链和侧链有机基团的不同代谢。