{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:10:02Z","timestamp":1792789802697,"version":"4.5.0"},"reference-count":32,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T00:00:00Z","timestamp":1790640000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Korea Institute for Advancement of Technology","award":["RS-2025-02263144"],"award-info":[{"award-number":["RS-2025-02263144"]}],"id":[{"id":"https:\/\/ror.org\/015w1qa96","id-type":"ROR","asserted-by":"crossref"}]},{"award":["RS-2025-02263144"],"award-info":[{"award-number":["RS-2025-02263144"]}],"id":[{"id":"https:\/\/ror.org\/015w1qa96","id-type":"ROR","asserted-by":"publisher"}]},{"name":"National Research Foundation of Korea","award":["RS-2026-25598074"],"award-info":[{"award-number":["RS-2026-25598074"]}],"id":[{"id":"https:\/\/ror.org\/013aysd81","id-type":"ROR","asserted-by":"crossref"}]},{"award":["RS-2026-25598074"],"award-info":[{"award-number":["RS-2026-25598074"]}],"id":[{"id":"https:\/\/ror.org\/013aysd81","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Despite their potential as reinforcing agents for poly(lactic acid) (PLA), cellulose nanocrystals (CNCs) tend to self-aggregate, limiting both optical transparency and mechanical reinforcement. In this study, incorporating poly(L-lactic acid)-grafted CNCs (LCNCs) into PLA simultaneously enhanced both optical transparency and mechanical reinforcement compared to neat CNCs. Three types of LCNCs\u2014LCNC1 (apparent molar substitution, MSapp = 3.36), LCNC2 (MSapp = 25.6), and LCNC3 (MSapp = 56.9)\u2014were synthesized. Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectra revealed poly(L-lactic acid) (PLLA) grafting onto the CNC surface, and the MSapp values were estimated from the 1H NMR peak integrals. X-ray diffraction patterns (XRD) showed that the native crystalline structure of the CNCs was preserved even after surface modification. LCNC3 (MSapp = 56.9) exhibited a smaller hydrodynamic size in an organic solvent, consistent with reduced aggregation, whereas LCNC1 (MSapp = 3.36) remained severely aggregated like neat CNCs. The PLA\/LCNC3 nanocomposite retained transparency comparable to neat PLA and achieved the highest tensile strength among the nanocomposites considered here. These results indicate that a higher MSapp, reflecting greater PLLA graft development on CNCs, is associated with improved dispersion, optical transparency, and mechanical reinforcement in PLA nanocomposites.<\/jats:p>","DOI":"10.3390\/polym18192370","type":"journal-article","created":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T08:12:42Z","timestamp":1790669562000},"page":"2370","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Graft Development in PLLA-Functionalized Cellulose Nanocrystals on Dispersibility, Transparency, and Mechanical Reinforcement in PLA Nanocomposites"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-0571-1476","authenticated-orcid":false,"given":"Hee Cheol","family":"Kang","sequence":"first","affiliation":[{"name":"Department of Materials Science and Engineering, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul 06978, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2082-9209","authenticated-orcid":false,"given":"Jae Woo","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul 06978, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Hwang, E., Yang, Y.-H., Choi, J., Park, S.-H., Park, K., and Lee, J. (2025). Biodegradable plastics as sustainable alternatives: Advances, basics, challenges, and directions for the future. Materials, 18.","DOI":"10.3390\/ma18184247"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1892","DOI":"10.1002\/ieam.4976","article-title":"Microplastics from petroleum-based plastics and their effects: A systematic literature review and science mapping of global bioplastics production","volume":"20","author":"Mutmainna","year":"2024","journal-title":"Integr. Environ. Assess. Manag."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Burelo, M., Acosta, S., Bedolla-Valdez, Z.I., R\u00edos-Gonz\u00e1lez, J.A., L\u00f3pez-Sandoval, R., Encinas, A., Escobar-Barrios, V., Gayt\u00e1n, I., and Stringer, T. (2026). Bio-Based Polymer Composites and Nanocomposites: A Sustainable Approach. Macromol, 6.","DOI":"10.3390\/macromol6020024"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Basavegowda, N., and Baek, K.-H. (2021). Advances in functional biopolymer-based nanocomposites for active food packaging applications. Polymers, 13.","DOI":"10.3390\/polym13234198"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"15095","DOI":"10.1039\/D5RA08379F","article-title":"Beyond fossil plastics: Next-generation PLA-based bio-packaging for industrial applications\u2013advances, challenges, and data-driven insights","volume":"16","author":"Hasoon","year":"2026","journal-title":"RSC Adv."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Mokhena, T., Sefadi, J., Sadiku, E., John, M., Mochane, M., and Mtibe, A. (2018). Thermoplastic processing of PLA\/cellulose nanomaterials composites. Polymers, 10.","DOI":"10.20944\/preprints201810.0477.v1"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1007\/s10570-016-1143-3","article-title":"Polysaccharide nanocrystals as fillers for PLA based nanocomposites","volume":"24","author":"Scaffaro","year":"2017","journal-title":"Cellulose"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Balla, E., Daniilidis, V., Karlioti, G., Kalamas, T., Stefanidou, M., Bikiaris, N.D., Vlachopoulos, A., Koumentakou, I., and Bikiaris, D.N. (2021). Poly(lactic Acid): A versatile biobased polymer for the future with multifunctional properties\u2014From monomer synthesis, polymerization techniques and molecular weight increase to PLA applications. Polymers, 13.","DOI":"10.3390\/polym13111822"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1002\/pen.26193","article-title":"Synthesis, properties, and applications of polylactic acid-based polymers","volume":"63","author":"Ebrahimi","year":"2023","journal-title":"Polym. Eng. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"58745","DOI":"10.1007\/s11356-024-35127-3","article-title":"Cellulose nanocrystals from agriculture and forestry biomass: Synthesis methods, characterization and industrial applications","volume":"31","author":"Qureshi","year":"2024","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Norizan, M.N., Shazleen, S.S., Alias, A.H., Sabaruddin, F.A., Asyraf, M.R.M., Zainudin, E.S., Abdullah, N., Samsudin, M.S., Kamarudin, S.H., and Norrrahim, M.N.F. (2022). Nanocellulose-based nanocomposites for sustainable applications: A review. Nanomaterials, 12.","DOI":"10.3390\/nano12193483"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1186\/s42269-025-01349-9","article-title":"Comprehensive review of cellulose nanocrystals: Preparation, properties, modifications and applications","volume":"49","author":"Sonowal","year":"2025","journal-title":"Bull. Natl. Res. Cent."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e00654","DOI":"10.1002\/adsu.202500654","article-title":"Engineering Poly(Lactic Acid)\/Cellulose Nanocrystal Composites: A Comparative Review of Preparation Strategies and their Influence on Structure-Property Relationships","volume":"9","author":"Ryoo","year":"2025","journal-title":"Adv. Sustain. Syst."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"118243","DOI":"10.1016\/j.carbpol.2021.118243","article-title":"Effect of solvent type on the dispersion quality of spray-and freeze-dried CNCs in PLA through rheological analysis","volume":"268","author":"Nofar","year":"2021","journal-title":"Carbohydr. Polym."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4350","DOI":"10.1016\/j.jmrt.2022.06.152","article-title":"Mussel-inspired polydopamine-modified cellulose nanocrystal fillers for the preparation of reinforced and UV-shielding poly (lactic acid) films","volume":"19","author":"Xu","year":"2022","journal-title":"J. Mater. Res. Technol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.cossms.2018.11.005","article-title":"Recent advances and an industrial perspective of cellulose nanocrystal functionalization through polymer grafting","volume":"23","author":"Kedzior","year":"2019","journal-title":"Curr. Opin. Solid State Mater. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"144552","DOI":"10.1016\/j.ijbiomac.2025.144552","article-title":"Advancements in cellulose nanocrystals: A review of functionalization, applications, and challenges","volume":"315","author":"Aziz","year":"2025","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5318","DOI":"10.1021\/acs.macromol.4c03064","article-title":"Molecular insights into interfacial dynamics and toughening mechanisms for poly(lactic acid)-grafted cellulose nanocrystal composites","volume":"58","author":"Wang","year":"2025","journal-title":"Macromolecules"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3661","DOI":"10.1021\/acsapm.3c00312","article-title":"Polymer-grafted cellulose nanofibrils with enhanced interfacial compatibility for stronger poly(lactic acid) composites","volume":"5","author":"Kelly","year":"2023","journal-title":"ACS Appl. Polym. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5055","DOI":"10.1002\/pen.70557","article-title":"Surface Grafting of Cellulose Nanocrystals Affects Interfacial Interaction and Crystallization of Polycaprolactone","volume":"66","author":"Peng","year":"2026","journal-title":"Polym. Eng. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1016\/j.carbpol.2018.05.087","article-title":"Green and facile surface modification of cellulose nanocrystal as the route to produce poly(lactic acid) nanocomposites with improved properties","volume":"197","author":"Wu","year":"2018","journal-title":"Carbohydr. Polym."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/j.eurpolymj.2016.09.019","article-title":"Effect of surface-grafted cellulose nanocrystals on the thermal and mechanical properties of PLLA based nanocomposites","volume":"84","author":"Roig","year":"2016","journal-title":"Eur. Polym. J."},{"key":"ref_23","unstructured":"(2022). Standard Test Method for Tensile Properties of Plastics (Standard No. ASTM D638-22). Available online: https:\/\/store.astm.org\/d0638-14.html."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1409","DOI":"10.1021\/mz3005956","article-title":"Organic catalysis for ring-opening polymerization","volume":"1","author":"Dove","year":"2012","journal-title":"ACS Macro Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1080\/20550324.2023.2285306","article-title":"Improved dispersibility of nanofibrillated cellulose via simple microwave-assisted esterification","volume":"9","author":"Klayya","year":"2023","journal-title":"Nanocomposites"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"7895","DOI":"10.1007\/s10570-024-06089-z","article-title":"Complete 1H and 13C NMR assignment of cellulose oligomer in LiCl\/DMSO","volume":"31","author":"Sasaki","year":"2024","journal-title":"Cellulose"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"873","DOI":"10.1007\/s10570-012-9847-5","article-title":"Direct grafting modification of pulp in ionic liquids and self-assembly behavior of the graft copolymers","volume":"20","author":"Guo","year":"2013","journal-title":"Cellulose"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Xiao, S., Yuan, T., Cao, H., Lin, D., Shen, Y., He, J., and Wang, B. (2012). Synthesis and characterization of cellulose-graft-poly(L-lactide) via ring-opening polymerization. Bioresources, 7.","DOI":"10.15376\/biores.7.2.1748-1759"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.1177\/08927057241254101","article-title":"Obtaining cellulose nanocrystals by acid hydrolysis procedure; and their use as reinforcement in polylactide biocomposites","volume":"38","author":"Kaynak","year":"2025","journal-title":"J. Thermoplast. Compos. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"885","DOI":"10.1007\/s10570-013-0030-4","article-title":"Idealized powder diffraction patterns for cellulose polymorphs","volume":"21","author":"French","year":"2014","journal-title":"Cellulose"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/j.carbpol.2016.01.041","article-title":"PLLA-grafted cellulose nanocrystals: Role of the CNC content and grafting on the PLA bionanocomposite film properties","volume":"142","author":"Lizundia","year":"2016","journal-title":"Carbohydr. Polym."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/S0926-6690(99)00009-6","article-title":"Rheological properties of amorphous and semicrystalline polylactic acid polymers","volume":"10","author":"Fang","year":"1999","journal-title":"Ind. Crops Prod."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/19\/2370\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T04:17:48Z","timestamp":1790828268000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/19\/2370"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,29]]},"references-count":32,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["polym18192370"],"URL":"https:\/\/doi.org\/10.3390\/polym18192370","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,29]]}}}