The increasing shortage in fossil resources creates a strong demand for the development of bio-based polymers with tailored properties, not competing with food resources. Polycarbonates, produced by ring-opening copolymerization (ROCOP) of epoxides and CO₂, are one promising material class to solve this issue. Poly(limonene carbonate) (PLimC) is a bio-based and non-food based polycarbonate made from limonene oxide (LimO) and CO₂. It features an exocyclic double bond at each repeating unit, which can be utilized for further functionalization reactions. However, the degree of functionalization is hardly controllable. Here, we demonstrate that random terpolymerization of LimO with its hydrogenated analogue menth-1-ene oxide (Men1O) and CO₂ gives access to polycarbonates with a defined number and homogeneous distribution of functional groups within the polymer chain. The reactivity ratios, determined by the Fineman-Ross and non-linear least square (NLLS) methods, are close to 1.0 for both LimO and Men1O, proving the random nature of the terpolymerization. The versatility of this synthetic platform is shown by thiol–ene click functionalization with 2-mercaptoethanol, yielding terpolymers with a defined number of pendant hydroxy groups. These are exemplarily used for fluorescence labelling of solution cast films with 5-fluorescein isothiocyanate (FITC), revealing a high accessibility of the pendant hydroxy groups for further reactions, even in heterogeneous systems.

中文翻译：

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具有特定功能的生物基无规三元共聚物，基于聚（碳酸柠檬烯-无规-1-碳酸烯）

化石资源的日益短缺产生了对开发具有定制特性的生物基聚合物的强烈需求，而不是与食物资源竞争。_{通过环氧化物和CO 2}的开环共聚(ROCOP) 生产的聚碳酸酯是解决这一问题的一类有前途的材料。聚柠檬烯碳酸酯 (PLimC) 是一种生物基和非食品基聚碳酸酯，由氧化柠檬烯 (LimO) 和 CO ₂制成。它的每个重复单元都有一个环外双键，可用于进一步的官能化反应。然而，功能化程度难以控制。在这里，我们证明了 LimO 与其氢化类似物薄荷-1-烯氧化物 (Men1O) 和 CO ₂的无规三聚可以得到在聚合物链内具有确定数量和均匀分布的官能团的聚碳酸酯。通过 Fineman-Ross 和非线性最小二乘 (NLLS) 方法测定的 LimO 和 Men1O 的反应率均接近 1.0，证明了三聚的随机性质。该合成平台的多功能性通过用 2-巯基乙醇进行硫醇-烯点击官能化来体现，产生具有确定数量的侧羟基的三元共聚物。这些示例性地用于使用 5-异硫氰酸荧光素 (FITC) 进行溶液流延薄膜的荧光标记，揭示了侧羟基对于进一步反应的高度可及性，即使在异质系统中也是如此。