The development of recyclable polymers has attracted considerable attention for realizing the development of a sustainable society. Polycarbonates (PCs) are engineering plastics with high thermal stability and transparency. We focused on poly(isosorbide carbonate) (PIC), a bio-based PC synthesized from isosorbide (ISB) derived from glucose. PIC is expected to function as an alternative to conventional PCs because of its outstanding transparency and thermal and physical properties. This study prepared PIC copolymers with several types of diol comonomers to clarify the effect of copolymerization on the decomposition reaction with ammonia, i.e., ammonolysis for converting PIC copolymers into monomers and urea. The thermal and physical properties of the resulting copolymers were also investigated. The thermal stability of the PIC copolymers remained stable after copolymerization, and the glass transition temperature was affected mainly by the flexibility of the structure of the introduced comonomer. A drastic change in mechanical properties was observed for the copolymer synthesized with 1,4-butanediol, which provides guidelines for toughening PIC with a small comonomer ratio. Finally, we investigated the decomposition behavior of the copolymers by treatment with aqueous ammonia. The PIC copolymers were decomposed into ISB, comonomers, and urea, and the ammonolysis rate was affected by the introduced structure. This study promotes the effective use of ISB as a biomass resource through ammonolysis, which is an effective chemical recycling process for polycarbonate.

为了实现可持续社会的发展，可回收聚合物的开发引起了人们的广泛关注。聚碳酸酯（PC）是具有高热稳定性和透明度的工程塑料。我们专注于聚（异山梨醇碳酸酯）（PIC），这是一种由葡萄糖衍生的异山梨醇（ISB）合成的生物基 PC。由于 PIC 具有出色的透明度以及热性能和物理性能，预计将成为传统 PC 的替代品。本研究用几种类型的二醇共聚单体制备了 PIC 共聚物，以阐明共聚对氨分解反应（即将 PIC 共聚物转化为单体和尿素的氨解反应）的影响。还研究了所得共聚物的热性能和物理性能。共聚后PIC共聚物的热稳定性保持稳定，玻璃化转变温度主要受引入共聚单体结构灵活性的影响。用 1,4-丁二醇合成的共聚物的机械性能发生了巨大变化，这为以小共聚单体比例增韧 PIC 提供了指导。最后，我们通过氨水处理研究了共聚物的分解行为。PIC共聚物分解为ISB、共聚单体和尿素，氨解速率受到引入结构的影响。这项研究通过氨解促进了ISB作为生物质资源的有效利用，氨解是一种有效的聚碳酸酯化学回收工艺。