{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T15:42:12Z","timestamp":1775490132626,"version":"3.50.1"},"reference-count":46,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,12,4]],"date-time":"2024-12-04T00:00:00Z","timestamp":1733270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Funds through the FCT\u2014Foundation for Science and Technology","award":["UIDB\/00681\/2020"],"award-info":[{"award-number":["UIDB\/00681\/2020"]}]},{"name":"Polytechnic University of Viseu","award":["UIDB\/00681\/2020"],"award-info":[{"award-number":["UIDB\/00681\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Agronomy"],"abstract":"<jats:p>Arbutus unedo (strawberry tree) is a small Mediterranean tree capable of vigorous regrowth after disturbances like fire. Traditionally used for biomass fuel, its bark and branches hold potential for higher-value products through ecovalorization into liquid mixtures that could replace petroleum-based materials. This study aimed to explore the chemical composition of various components of Arbutus unedo and to produce a liquefied material from its internal (IB) and external bark (EB). Chemical compositions of internal and external bark were determined using TAPPI standards including ash, extractive content, lignin, and cellulose. Metal cations were analyzed by ICP. Liquefaction of bark was optimized in a PARR reactor, evaluating factors such as particle size, temperature, and time, and the best polyols were monitored by FTIR-ATR. Polyurethane foams were made with internal and external bark materials liquefied by polymerization with isocyanate, a catalyst, and water as a blowing agent. Results showed that EB has a higher extractive and lignin content, while IB contains more cellulose. Liquefaction yields were higher for IB (74%) than EB (68%), with IB yielding polyols that produced stronger and more resilient foams with higher compressive strength and modulus of elasticity. Mechanical properties of the foams were influenced by the NCO\/OH ratio and catalyst levels. Overall, the internal bark demonstrated superior performance for foam production, highlighting its potential as an eco-friendly alternative to petroleum-derived materials.<\/jats:p>","DOI":"10.3390\/agronomy14122893","type":"journal-article","created":{"date-parts":[[2024,12,4]],"date-time":"2024-12-04T04:47:22Z","timestamp":1733287642000},"page":"2893","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Valorization of Arbutus unedo L. Bark Through Chemical Composition Analysis, Liquefaction, and Bio-Based Foam Production"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6502-7202","authenticated-orcid":false,"given":"Lu\u00edsa","family":"Cruz-Lopes","sequence":"first","affiliation":[{"name":"CERNAS (Centre for Natural Resources, Environment and Society), IPV Research Centre, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"},{"name":"Department of Environmental Engineering, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2414-8240","authenticated-orcid":false,"given":"Yuliya","family":"Dulyanska","sequence":"additional","affiliation":[{"name":"CERNAS (Centre for Natural Resources, Environment and Society), IPV Research Centre, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"},{"name":"Department of Environmental Engineering, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"}]},{"given":"Rog\u00e9rio","family":"Lopes","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering and Industrial Management, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4308-1563","authenticated-orcid":false,"given":"Idalina","family":"Domingos","sequence":"additional","affiliation":[{"name":"CERNAS (Centre for Natural Resources, Environment and Society), IPV Research Centre, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"},{"name":"Department of Wood Engineering, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7596-8065","authenticated-orcid":false,"given":"Jos\u00e9","family":"Ferreira","sequence":"additional","affiliation":[{"name":"CERNAS (Centre for Natural Resources, Environment and Society), IPV Research Centre, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"},{"name":"Department of Wood Engineering, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6660-3128","authenticated-orcid":false,"given":"Bruno","family":"Esteves","sequence":"additional","affiliation":[{"name":"CERNAS (Centre for Natural Resources, Environment and Society), IPV Research Centre, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"},{"name":"Department of Wood Engineering, Polytechnic University of Viseu, Av. Cor. Jos\u00e9 Maria Vale de Andrade, 3504-510 Viseu, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1023\/A:1015864821706","article-title":"Arbutus unedo L. Communities in Southern Iberian Peninsula Mountains","volume":"160","author":"Torres","year":"2002","journal-title":"Plant Ecol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1007\/s11676-021-01369-x","article-title":"Biotechnology of the Multipurpose Tree Species Arbutus Unedo: A Review","volume":"33","author":"Martins","year":"2022","journal-title":"J. For. 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