{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T01:17:02Z","timestamp":1788225422982,"version":"build-2803163510"},"reference-count":37,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100014188","name":"Korea Institute of Oriental Medicine","doi-asserted-by":"publisher","award":["KSN2512012"],"award-info":[{"award-number":["KSN2512012"]}],"id":[{"id":"10.13039\/501100014188","id-type":"DOI","asserted-by":"publisher"}]},{"award":["KSN2512012"],"award-info":[{"award-number":["KSN2512012"]}],"id":[{"id":"https:\/\/ror.org\/005rpmt10","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Poly(L-lactic acid) (PLLA) nanofibers are promising materials for biomedical and packaging applications; however, their inherent brittleness limits applications requiring both stiffness and ductility. Here, \u03b1- and \u03b2-chitin, differing in molecular packing and hydrogen-bonding characteristics, were incorporated into electrospun PLLA nanofibers at a PLLA\/chitin mass ratio of 10:1. Both chitin types enhanced the mechanical properties of PLLA, increasing tensile strength by 1.4- and 1.6-fold and Young\u2019s modulus to 83.7 and 79.7 MPa for PLLA\/\u03b1-chitin and PLLA\/\u03b2-chitin, respectively. PLLA\/\u03b1-chitin exhibited higher yield strength and more uniform fiber morphology, whereas PLLA\/\u03b2-chitin showed substantially greater ductility and toughness with pronounced necking behavior. Thermal, spectroscopic, and diffraction analyses revealed distinct structural responses associated with the two chitin forms. \u03b1-Chitin produced a constrained hydrogen-bonded environment that restricted PLLA chain mobility. In contrast, \u03b2-chitin preserved greater chain mobility and promoted a more heterogeneous local molecular environment. Despite its lower overall crystallinity, PLLA\/\u03b2-chitin exhibited a distinct secondary melting feature, suggesting localized chain organization and a limited nucleation effect rather than enhanced bulk crystallization. These findings demonstrate that chitin structure provides a practical design parameter for balancing stiffness and toughness in PLLA nanofiber composites, broadening their potential applications in the biomedical and packaging fields.<\/jats:p>","DOI":"10.3390\/polym18172127","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T01:05:26Z","timestamp":1788224726000},"page":"2127","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of \u03b1- and \u03b2-Chitin on the Mechanical Properties and Molecular Interactions of Electrospun PLLA Nanofibers"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4205-5371","authenticated-orcid":false,"given":"Seunghwan","family":"Choy","sequence":"first","affiliation":[{"name":"Digital Health Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1891","DOI":"10.1016\/j.biomaterials.2003.08.062","article-title":"Fabrication of nano-structured porous PLLA scaffold intended for nerve tissue engineering","volume":"25","author":"Yang","year":"2004","journal-title":"Biomaterials"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"27687","DOI":"10.1039\/D2RA04241J","article-title":"Raman mapping of piezoelectric poly (l-lactic acid) films for force sensors","volume":"12","author":"Babichuk","year":"2022","journal-title":"RSC Adv."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"120553","DOI":"10.1016\/j.carbpol.2023.120553","article-title":"Nano-Chitin: Preparation strategies and food biopolymer film reinforcement and applications","volume":"305","author":"Liao","year":"2023","journal-title":"Carbohydr. 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