Jackson Alexander W, Reddy Mothe Srinivasa, Chennamaneni Lohitha Rao, van Herk Alexander, Thoniyot Praveen
Institute of Chemical and Engineering Sciences (ICES), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore.
Materials (Basel). 2020 May 19;13(10):2325. doi: 10.3390/ma13102325.
Degradable analogues of polystyrene are synthesized via radical ring-opening (co)polymerization (rROP) between styrene and two cyclic ketene acetals, namely 2-methylene-1,3-dioxepane (MDO) and 5,6-benzo-2-methylene-1,3-dioxepane (BMDO). This approach periodically inserts ester bonds throughout the main chain of polystyrene, imparting a degradation pathway via ester hydrolysis. We discuss the historical record of this approach, with careful attention paid to the conflicting findings previously reported. We have found a common H NMR characterization error, repeated throughout the existing body of work. This misinterpretation is responsible for the discrepancies within the cyclic ketene acetal (CKA)-based degradable polystyrene literature. These inconsistencies, for the first time, are now understood and resolved through optimization of the polymerization conditions, and detailed characterization of the degradable copolymers and their corresponding oligomers after hydrolytic degradation.
通过苯乙烯与两种环状乙烯酮缩醛，即2-亚甲基-1,3-二氧六环（MDO）和5,6-苯并-2-亚甲基-1,3-二氧六环（BMDO）之间的自由基开环（共）聚合（rROP）反应，合成了聚苯乙烯的可降解类似物。这种方法会在聚苯乙烯主链上周期性地插入酯键，通过酯水解赋予其降解途径。我们讨论了这种方法的历史记录，并仔细关注了先前报道的相互矛盾的研究结果。我们发现了一个常见的氢核磁共振（H NMR）表征错误，在现有的研究工作中反复出现。这种误解导致了基于环状乙烯酮缩醛（CKA）的可降解聚苯乙烯文献中的差异。现在，通过优化聚合条件，以及对水解降解后的可降解共聚物及其相应低聚物进行详细表征，首次理解并解决了这些不一致之处。
