van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands.
van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands.
Sci Total Environ. 2022 Apr 1;815:152781. doi: 10.1016/j.scitotenv.2021.152781. Epub 2022 Jan 4.
In order to reduce the plastic accumulation in the environment, biodegradable plastics are attracting interest in the plastics market. However, the low thermal stability of most amorphous biodegradable polymers limits their application. With the aim of combining high glass transition temperature (T), with good (marine) biodegradation a family of novel fully renewable poly(isosorbide-co-diol) oxalate (PISOX-diol) copolyesters was recently developed. In this study, the biodegradability of a representative copolyester, poly(isosorbide-co-1,6-hexanediol) oxalate (PISOX-HDO), with 75/25 mol ratio IS/HDO was evaluated at ambient temperature (25 °C) in soil and marine environment by using a Respicond system with 95 parallel reactors, based on the principle of frequently monitoring CO evolution. During 50 days incubation in soil and seawater, PISOX-HDO mineralised faster than cellulose. The ready biodegradability of PISOX-HDO is related to the relatively fast non-enzymatic hydrolysis of polyoxalates. To study the underlying mechanism of PISOX-HDO biodegradation, the non-enzymatic hydrolysis of PISOX-HDO and the biodegradation of the monomers in soil were also investigated. Complete hydrolysis was obtained in approximately 120 days (tracking the formation of hydrolysis products via H NMR). It was also shown that (enzymatic) hydrolysis to the constituting monomers is the rate-determining step in this biodegradation mechanism. These monomers can subsequently be consumed and mineralised by (micro)organisms in the environment much faster than the polyesters. The combination of high T (>100 °C) and fast biodegradability is quite unique and makes this PISOX-HDO copolyester ideal for short term applications that demand strong mechanical and physical properties.
为了减少环境中的塑料积累，可生物降解塑料在塑料市场中受到关注。然而，大多数无定形可生物降解聚合物的热稳定性低限制了它们的应用。为了将高玻璃化转变温度（T）与良好的（海洋）生物降解性结合起来，最近开发了一系列新型完全可再生的聚（异山梨醇-co-二醇）草酸酯（PISOX-diol）共聚酯。在这项研究中，通过使用带有 95 个平行反应器的 Respicond 系统，根据频繁监测 CO 释放的原理，在环境温度（25°C）下，在土壤和海洋环境中评估了具有 75/25 mol 比 IS/HDO 的代表性共聚酯，聚（异山梨醇-co-1,6-己二醇）草酸酯（PISOX-HDO）的生物降解性。在土壤和海水中孵育 50 天期间，PISOX-HDO 的矿化速度快于纤维素。PISOX-HDO 的可快速生物降解性与聚草酸酯的相对快速的非酶水解有关。为了研究 PISOX-HDO 生物降解的潜在机制，还研究了 PISOX-HDO 的非酶水解和土壤中单体的生物降解。通过 1 H NMR 跟踪水解产物的形成，在大约 120 天内即可获得完全水解。还表明，（酶促）水解为构成单体是该生物降解机制中的速率决定步骤。这些单体随后可以被环境中的（微生物）更快地消耗和矿化，而不是聚酯。高 T（>100°C）和快速生物降解性的结合是非常独特的，这使得 PISOX-HDO 共聚酯非常适合需要高强度机械和物理性能的短期应用。
