{"title":"Stereoregular polyamides with optically-pure aspartame-type diketopiperazine derivatives","authors":"Kenji Takada, Hongrong Yin, Tatsuo Kaneko","doi":"10.1002/pol.20240549","DOIUrl":null,"url":null,"abstract":"<p>Polyamides (PAs) with aspartame-derived diketopiperazine (DKP) form specific particles and exhibit high heat resistance. In this study, we investigated the stereostructures of aspartic acid and phenylalanine, which constitute aspartame DKP. Diketopiperazines with different stereostructures were synthesized from D- and L-aspartic acid and D- and L-phenylalanine, and LL-, DD-, and LD-type aminodiketopiperazines (LL, DD, and LD-ADKPs) were obtained. These ADKPs differed in their crystal forms depending on their stereoisomeric structures. Furthermore, PAs were formed from these ADKPs via polycondensation using triphenyl phosphite/pyridine, and their heat resistance was approximately 300 °C. The secondary structure of each PA was evaluated by circular dichroism, which suggested that LD-type PAs had a mixed secondary structure of coils and helical structures, unlike the LL and DD types. Precipitated LL, DD, and LLcoDD PAs formed similar particles, whereas the particles of the large LD-type PA had different particle shapes owing to their different conformations.</p>","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"62 22","pages":"5089-5097"},"PeriodicalIF":3.9000,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Polymer Science","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/pol.20240549","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Polyamides (PAs) with aspartame-derived diketopiperazine (DKP) form specific particles and exhibit high heat resistance. In this study, we investigated the stereostructures of aspartic acid and phenylalanine, which constitute aspartame DKP. Diketopiperazines with different stereostructures were synthesized from D- and L-aspartic acid and D- and L-phenylalanine, and LL-, DD-, and LD-type aminodiketopiperazines (LL, DD, and LD-ADKPs) were obtained. These ADKPs differed in their crystal forms depending on their stereoisomeric structures. Furthermore, PAs were formed from these ADKPs via polycondensation using triphenyl phosphite/pyridine, and their heat resistance was approximately 300 °C. The secondary structure of each PA was evaluated by circular dichroism, which suggested that LD-type PAs had a mixed secondary structure of coils and helical structures, unlike the LL and DD types. Precipitated LL, DD, and LLcoDD PAs formed similar particles, whereas the particles of the large LD-type PA had different particle shapes owing to their different conformations.
期刊介绍:
Journal of Polymer Research provides a forum for the prompt publication of articles concerning the fundamental and applied research of polymers. Its great feature lies in the diversity of content which it encompasses, drawing together results from all aspects of polymer science and technology.
As polymer research is rapidly growing around the globe, the aim of this journal is to establish itself as a significant information tool not only for the international polymer researchers in academia but also for those working in industry. The scope of the journal covers a wide range of the highly interdisciplinary field of polymer science and technology.