Aya Katto, Sadahito Aoshima and Arihiro Kanazawa*,
{"title":"Sugar-Derived Cyclic Acetals as Comonomers for Cationic Copolymerization with Vinyl Ethers","authors":"Aya Katto, Sadahito Aoshima and Arihiro Kanazawa*, ","doi":"10.1021/acs.macromol.4c00847","DOIUrl":null,"url":null,"abstract":"<p >Sugar-derived cyclic acetals were demonstrated to undergo cationic copolymerization with a vinyl ether (VE) via the vinyl-addition and ring-opening mechanisms. Cyclic acetals were synthesized by the condensation reactions of sugar alcohols (mannitol, xylose, erythritol, and sorbitol) with aldehydes or ketones. These cyclic acetals differ in the number of cyclic acetal moieties, the number of ring members, substituents, and stereo configuration. Such structural features greatly affected the copolymerization behavior. For example, erythritol-derived cyclic acetals consisting of two isolated five-membered cyclic acetal moieties undergo copolymerization with 2-chloroethyl VE, while mannitol-derived cyclic acetals consisting of three fused seven- and six-membered cyclic acetal moieties were not incorporated into polymer chains. Moreover, a xylose-derived cyclic acetal that has a <i>p</i>-methoxyphenyl substituent at the carbon atom adjacent to two oxygen atoms underwent copolymerization most effectively among the cyclic acetals examined in this study, which is likely due to the efficient generation of a carbocation via ring-opening. In addition, cationic initiators or Lewis acid catalysts affected the frequency of crossover reactions, resulting in a difference in incorporated ratios of sugar-derived cyclic acetals in polymer chains. The copolymers synthesized from VEs and sugar-derived cyclic acetals were degraded by acid via cleavage of the VE-to-cyclic acetal crossover reaction-derived acetal moieties in the main chain. A gluconic acid-derived cyclic acetal that has both cyclic acetal and cyclic hemiacetal ester moieties was ineffective for copolymerization with a VE, whereas an oxirane was successfully copolymerized with the gluconic acid-derived monomer via the ring-opening of the cyclic hemiacetal ester moiety.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.1000,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Macromolecules","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.macromol.4c00847","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Sugar-derived cyclic acetals were demonstrated to undergo cationic copolymerization with a vinyl ether (VE) via the vinyl-addition and ring-opening mechanisms. Cyclic acetals were synthesized by the condensation reactions of sugar alcohols (mannitol, xylose, erythritol, and sorbitol) with aldehydes or ketones. These cyclic acetals differ in the number of cyclic acetal moieties, the number of ring members, substituents, and stereo configuration. Such structural features greatly affected the copolymerization behavior. For example, erythritol-derived cyclic acetals consisting of two isolated five-membered cyclic acetal moieties undergo copolymerization with 2-chloroethyl VE, while mannitol-derived cyclic acetals consisting of three fused seven- and six-membered cyclic acetal moieties were not incorporated into polymer chains. Moreover, a xylose-derived cyclic acetal that has a p-methoxyphenyl substituent at the carbon atom adjacent to two oxygen atoms underwent copolymerization most effectively among the cyclic acetals examined in this study, which is likely due to the efficient generation of a carbocation via ring-opening. In addition, cationic initiators or Lewis acid catalysts affected the frequency of crossover reactions, resulting in a difference in incorporated ratios of sugar-derived cyclic acetals in polymer chains. The copolymers synthesized from VEs and sugar-derived cyclic acetals were degraded by acid via cleavage of the VE-to-cyclic acetal crossover reaction-derived acetal moieties in the main chain. A gluconic acid-derived cyclic acetal that has both cyclic acetal and cyclic hemiacetal ester moieties was ineffective for copolymerization with a VE, whereas an oxirane was successfully copolymerized with the gluconic acid-derived monomer via the ring-opening of the cyclic hemiacetal ester moiety.
研究证明,糖类衍生环缩醛可通过乙烯基加成和开环机制与乙烯基醚(VE)发生阳离子共聚。环状缩醛是通过糖醇(甘露醇、木糖、赤藓糖醇和山梨醇)与醛或酮的缩合反应合成的。这些环状缩醛在环状缩醛分子的数量、环状成员的数量、取代基和立体构型方面各不相同。这些结构特征在很大程度上影响了共聚行为。例如,赤藓糖醇衍生的环缩醛由两个孤立的五元环缩醛分子组成,可与 2-Cloroethyl VE 发生共聚,而甘露醇衍生的环缩醛由三个融合的七元和六元环缩醛分子组成,不能与聚合物链结合。此外,在本研究考察的环缩醛中,木糖衍生的环缩醛在邻近两个氧原子的碳原子上具有对甲氧基苯基取代基,能最有效地进行共聚,这可能是由于通过开环有效地生成了碳位。此外,阳离子引发剂或路易斯酸催化剂也会影响交叉反应的频率,从而导致聚合物链中糖环乙醛的掺入比例不同。由 VE 和糖衍生环缩醛合成的共聚物在酸的作用下通过裂解主链中 VE 到环缩醛交叉反应衍生的缩醛分子而降解。同时具有环缩醛和环半缩醛酯分子的葡萄糖酸衍生环缩醛无法与 VE 进行共聚,而环氧乙烷则可以通过环半缩醛酯分子的开环反应成功地与葡萄糖酸衍生单体进行共聚。
期刊介绍:
Macromolecules publishes original, fundamental, and impactful research on all aspects of polymer science. Topics of interest include synthesis (e.g., controlled polymerizations, polymerization catalysis, post polymerization modification, new monomer structures and polymer architectures, and polymerization mechanisms/kinetics analysis); phase behavior, thermodynamics, dynamic, and ordering/disordering phenomena (e.g., self-assembly, gelation, crystallization, solution/melt/solid-state characteristics); structure and properties (e.g., mechanical and rheological properties, surface/interfacial characteristics, electronic and transport properties); new state of the art characterization (e.g., spectroscopy, scattering, microscopy, rheology), simulation (e.g., Monte Carlo, molecular dynamics, multi-scale/coarse-grained modeling), and theoretical methods. Renewable/sustainable polymers, polymer networks, responsive polymers, electro-, magneto- and opto-active macromolecules, inorganic polymers, charge-transporting polymers (ion-containing, semiconducting, and conducting), nanostructured polymers, and polymer composites are also of interest. Typical papers published in Macromolecules showcase important and innovative concepts, experimental methods/observations, and theoretical/computational approaches that demonstrate a fundamental advance in the understanding of polymers.