{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T08:22:16Z","timestamp":1787559736156,"version":"build-2736575974"},"reference-count":27,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T00:00:00Z","timestamp":1787529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Ornamental palm pruning residues represent a locally abundant, underutilized lignocellulosic waste stream with potential as a waste-valorized epoxy reinforcement. This study investigates the flexural behavior of particulate epoxy composites reinforced with Washingtonia robusta leaf stalk residue, evaluating the influence of reinforcement granulometry on mechanical and microstructural response. Four specimen families were fabricated from a Bisphenol A\/F epoxy resin cured with a cycloaliphatic amine hardener: neat resin (RS, reference) and composites reinforced with fine (RF), coarse (RG) and mixed-fraction (RM) particles at 20 vol.% loading. Flexural properties were assessed by three-point bending and fracture surfaces were characterized by SEM. The neat resin exhibited a non-monotonic, viscoelastic-dominated response with no fracture within the extended deformation range tested, whereas all reinforced systems fractured within a substantially narrower window (~8\u201314.5 mm). RF showed the highest observed flexural modulus (\u224815.8 GPa), followed by RM (\u224815.4 GPa) and RG (\u224814.2 GPa). These differences were not statistically significant (one-way ANOVA, p &gt; 0.05). Damage tolerance followed a similar descriptive trend: RG failed earliest, linked to large interfacial pull-out cavities; RF delayed fracture through crack deflection; and RM showed the most favorable overall balance, combining a modulus comparable to RF with superior crack path tortuosity. These results indicate the potential of Washingtonia robusta, particularly in mixed-granulometry form, as a candidate reinforcement for semi-structural epoxy biocomposites, pending further characterization of properties such as tensile strength, impact resistance, moisture absorption, and long-term durability.<\/jats:p>","DOI":"10.3390\/polym18172050","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T08:03:41Z","timestamp":1787558621000},"page":"2050","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Effect of Granulometry on the Flexural Behavior of Epoxy\/Washingtonia robusta Particulate Biocomposites from Conc\u00f3n, Chile"],"prefix":"10.3390","volume":"18","author":[{"given":"H\u00e9ctor Michael","family":"Solar Cort\u00e9s","sequence":"first","affiliation":[{"name":"Escuela de Ingenier\u00eda Mec\u00e1nica, Pontificia Universidad Cat\u00f3lica de Valpara\u00edso, Valpara\u00edso 2430000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar\u00eda Elena","family":"Fern\u00e1ndez Abreu","sequence":"additional","affiliation":[{"name":"Escuela de Ingenier\u00eda Mec\u00e1nica, Pontificia Universidad Cat\u00f3lica de Valpara\u00edso, Valpara\u00edso 2430000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1584-6901","authenticated-orcid":false,"given":"Jos\u00e9 Luis","family":"Valin Rivera","sequence":"additional","affiliation":[{"name":"Escuela de Ingenier\u00eda Mec\u00e1nica, Pontificia Universidad Cat\u00f3lica de Valpara\u00edso, Valpara\u00edso 2430000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2339-3719","authenticated-orcid":false,"given":"Meyl\u00ed","family":"Valin Fern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering (DIM), Faculty of Engineering (FI), University of Concepci\u00f3n, Concepci\u00f3n 4070409, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel Francisco","family":"Leiva Palomera","sequence":"additional","affiliation":[{"name":"Escuela de Ingenier\u00eda Mec\u00e1nica, Pontificia Universidad Cat\u00f3lica de Valpara\u00edso, Valpara\u00edso 2430000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roberto Iquilio","family":"Abarz\u00faa","sequence":"additional","affiliation":[{"name":"Escuela de Ingenier\u00eda Mec\u00e1nica, Pontificia Universidad Cat\u00f3lica de Valpara\u00edso, Valpara\u00edso 2430000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0754-2390","authenticated-orcid":false,"given":"Gilberto","family":"Garcia del Pino","sequence":"additional","affiliation":[{"name":"Departamento de Engenharia Mec\u00e2nica, Universidade do Estado do Amazonas (UEA), Manaus 69050-020, Amazonas, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"101271","DOI":"10.1016\/j.rineng.2023.101271","article-title":"201CA comprehensive review of natural fibers and their composites: An eco-friendly alternative to conventional materials","volume":"19","author":"Elfaleh","year":"2023","journal-title":"Results Eng."},{"key":"ref_2","first-page":"26349833211007502","article-title":"Mechanical properties of particulate organic natural filler-reinforced polymer composite: A review","volume":"30","author":"Kuan","year":"2021","journal-title":"Compos. 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