{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T05:45:32Z","timestamp":1776923132038,"version":"3.51.2"},"reference-count":22,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2018,7,26]],"date-time":"2018-07-26T00:00:00Z","timestamp":1532563200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007434","name":"Ag\u00eancia Nacional de Inova\u00e7\u00e3o","doi-asserted-by":"publisher","award":["17930"],"award-info":[{"award-number":["17930"]}],"id":[{"id":"10.13039\/501100007434","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Polyurea\/polyurethane (PUa\/PU) shell microcapsules (MCs), containing high loadings of isophorone diisocyanate (IPDI) in the core, were developed to enable the production of mono-component, eco-friendly and safer adhesive formulations for the footwear industry. IPDI microencapsulation was obtained via oil\u2013in\u2013water (O\/W) microemulsion combined with interfacial polymerization. A methylene diphenyl diisocyanate (MDI) compound (a commercial blend of monomeric and polymeric species), with higher reactivity than IPDI and low viscosity, was added to the O phase to competitively contribute to the shell formation, improving its quality. Four different active H sources were tested, aimed at achieving a high encapsulation yield. The successful encapsulation of IPDI was confirmed by Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), while the MCs\u2019 morphology and size distribution were assessed by scanning electron microscopy (SEM). The incorporation of a multifunctional isocyanate silane in the O phase, as \u201clatent\u201d active H source, led to the formation of impermeable PUa\/PU-silica hybrid shell MCs with more than 60 wt.% of pure encapsulated IPDI. A proof-of-concept study shows high peeling strength and a structural type of failure of the adhesive joint, revealing an effective IPDI release. These new engineered MCs are found to be promising crosslinkers for mono-component adhesives for high demanding applications.<\/jats:p>","DOI":"10.3390\/polym10080825","type":"journal-article","created":{"date-parts":[[2018,7,26]],"date-time":"2018-07-26T11:32:07Z","timestamp":1532604727000},"page":"825","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Isophorone Diisocyanate (IPDI) Microencapsulation for Mono-Component Adhesives: Effect of the Active H and NCO Sources"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1983-5457","authenticated-orcid":false,"given":"Mahboobeh","family":"Attaei","sequence":"first","affiliation":[{"name":"CERENA, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"given":"M\u00f3nica V.","family":"Loureiro","sequence":"additional","affiliation":[{"name":"CERENA, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"given":"M\u00e1rio","family":"Do Vale","sequence":"additional","affiliation":[{"name":"CERENA, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"given":"Jos\u00e9 A. D.","family":"Conde\u00e7o","sequence":"additional","affiliation":[{"name":"CERENA, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"given":"Isabel","family":"Pinho","sequence":"additional","affiliation":[{"name":"CIPADE\u2014Ind\u00fastria e Investiga\u00e7\u00e3o de Produtos Adesivos, SA. Av. 1\u00b0 de Maio, 518 Z. Industrial 1, Apt. 82, 3701-909 S\u00e3o Jo\u00e3o da Madeira, Portugal"}]},{"given":"Jo\u00e3o C.","family":"Bordado","sequence":"additional","affiliation":[{"name":"CERENA, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2947-1186","authenticated-orcid":false,"given":"Ana C.","family":"Marques","sequence":"additional","affiliation":[{"name":"CERENA, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2018,7,26]]},"reference":[{"key":"ref_1","unstructured":"Langenberg, K.V., Warden, P., Adam, C., and Milner, H.R. (2010). The Durability of Isocyanate-Based Adhesives under Service in Australian Conditions. The Results from a 3 Year Exposure Study Accelerated Testing Regime (Literature Review), Forest & Wood Products Australia Limited."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Hu, M., Guo, J., Yu, Y., Cao, L., and Xu, Y. (2017). Research Advances of Microencapsulation and Its Prospects in the Petroleum Industry. Materials, 10.","DOI":"10.3390\/ma10040369"},{"key":"ref_3","unstructured":"Karsa, D.R., and Stephenson, R.A. (2016). Microencapsulation via In Situ Polymerization. Handbook of Encapsulation and Controlled Release, Woodhead Publishing Limited, Taylor & Francis Group, LLC."},{"key":"ref_4","first-page":"13405","article-title":"Controlling the morphology of polyurea microcapsules using microfluidics","volume":"44","author":"Poland","year":"2014","journal-title":"Langmuir"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"9650","DOI":"10.1021\/ma801718v","article-title":"Microencapsulation of Isocyanates for Self-Healing Polymers","volume":"41","author":"Yang","year":"2008","journal-title":"Macromolecules"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1159","DOI":"10.1039\/C4PY01448K","article-title":"Efficient microencapsulation of a liquid isocyanate with in situ shell functionalization","volume":"6","author":"Nguyen","year":"2014","journal-title":"Polym. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2467","DOI":"10.1016\/j.eurpolymj.2013.02.006","article-title":"An efficient method for the output of new self-repairing materials through a reactive isocyanate encapsulation","volume":"49","author":"Credico","year":"2013","journal-title":"Eur. Polym. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1080\/02652048.2016.1178352","article-title":"Preparation of polyurea\/melamine formaldehyde double-layered self-healing microcapsules and investigation on core fraction","volume":"33","author":"Ming","year":"2016","journal-title":"J. Microencapsul."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3038","DOI":"10.1002\/pola.24740","article-title":"Polyurea microcapsules: Surface modification and capsule size control","volume":"49","author":"Li","year":"2011","journal-title":"J. Polym. Sci. A Polym. Chem."},{"key":"ref_10","first-page":"446","article-title":"Polyurethane microcapsule with glycerol as the polyol component for encapsulated self-healing agent","volume":"2","author":"Sondari","year":"2010","journal-title":"IJET"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.porgcoat.2015.09.009","article-title":"Preparation of polyurethane microcapsules with different polyols component for encapsulation of isophorone diisocyanate healing agent","volume":"89","author":"Kardar","year":"2015","journal-title":"Prog. Org. Coat."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1016\/j.micromeso.2017.10.056","article-title":"Hybrid custom-tailored sol-gel derived microscaffolds for biocides immobilization","volume":"261","author":"Loureiro","year":"2018","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"5380","DOI":"10.1007\/s10853-017-0782-6","article-title":"Amino-silica microcapsules as effective curing agents for polyurethane foams","volume":"52","author":"Loureiro","year":"2017","journal-title":"J. Mater. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/j.micromeso.2016.10.039","article-title":"Organically-modified silica based microspheres for self-curing polyurethane one component foams","volume":"244","author":"Loureiro","year":"2017","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1186\/s40508-014-0024-z","article-title":"Green-Caps: Towards solid curing agents for sustainable polyurethane foams","volume":"2","author":"Ciriminna","year":"2014","journal-title":"Sustain. Chem. Process."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Klein, L., Aparicio, M., and Jitianu, A. (2016). Characterization of Sol\u2013Gel Materials by Infrared Spectroscopy. Handbook of Sol-Gel Science and Technology, Springer.","DOI":"10.1007\/978-3-319-19454-7"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"9147","DOI":"10.1039\/C7CC05132H","article-title":"One-pot preparation of polymer microspheres having wrinkled hard surfaces through self-assembly of silica nanoparticles","volume":"53","author":"Hano","year":"2017","journal-title":"Chem. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"11123","DOI":"10.1039\/c1jm10794a","article-title":"Facile microencapsulation of HDI for self-healing anticorrosion coatings","volume":"21","author":"Huang","year":"2011","journal-title":"J. Mater. Chem."},{"key":"ref_19","first-page":"715","article-title":"Designing of polyamidoamine-based polyurea microcapsules containing tung oil for anticorrosive coating applications","volume":"13","author":"Tatiya","year":"2016","journal-title":"JCT Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1764","DOI":"10.1002\/jbm.b.32743","article-title":"Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement","volume":"7","author":"Brochu","year":"2012","journal-title":"J. Biomed. Mater. Res. B Appl. Biomater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"13749","DOI":"10.1039\/C5TA02288F","article-title":"Multilayer composite microcapsule synthesized by Pickering emulsion templates and its application in self-healing coating","volume":"3","author":"Yi","year":"2015","journal-title":"J. Mater. Chem. A"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"16214","DOI":"10.1039\/C4RA00213J","article-title":"Polyurethane Microcapsules for Self-Healing Paint Coatings","volume":"4","author":"Koh","year":"2014","journal-title":"RSC Adv."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/10\/8\/825\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:14:33Z","timestamp":1760195673000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/10\/8\/825"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,7,26]]},"references-count":22,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2018,8]]}},"alternative-id":["polym10080825"],"URL":"https:\/\/doi.org\/10.3390\/polym10080825","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,7,26]]}}}