{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T09:50:30Z","timestamp":1781862630976,"version":"3.54.5"},"reference-count":41,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,5,7]],"date-time":"2022-05-07T00:00:00Z","timestamp":1651881600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Technology Innovation Institute"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>In this work, tung oil was utilised as a catalyst-free self-healing agent, and an in-situ polymerization process was applied to encapsulate the tung oil core with a poly(urea-formaldehyde) (PUF) shell. The conventional poly(ethylene-alt-maleic-anhydride) (PEMA) polymer was compared to a more naturally abundant gelatin (GEL) emulsifier to compare the microcapsules\u2019 barrier, morphological, thermal, and chemical properties, and the crystalline nature of the shell material. GEL emulsifiers produced microcapsules with a higher payload (96.5%), yield (28.9%), and encapsulation efficiency (61.7%) compared to PEMA (90.8%, 28.6% and 52.6%, respectively). Optical and electron microscopy imaging indicated a more uniform morphology for the GEL samples. The thermal decomposition measurements indicated that GEL decomposed to a value 7% lower than that of PEMA, which was suggested to be attributed to the much thinner shell materials that the GEL samples produced. An innovative and novel focused ion beam (FIB) milling method was exerted on the GEL sample, confirming the storage and release of the active tung oil material upon rupturing. The samples with GEL conveyed a higher healing efficiency of 91%, compared to PEMA\u2019s 63%, and the GEL samples also conveyed higher levels of corrosion resistance.<\/jats:p>","DOI":"10.3390\/polym14091907","type":"journal-article","created":{"date-parts":[[2022,5,8]],"date-time":"2022-05-08T21:31:20Z","timestamp":1652045480000},"page":"1907","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["The Microencapsulation of Tung Oil with a Natural Hydrocolloid Emulsifier for Extrinsic Self-Healing Applications"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0019-096X","authenticated-orcid":false,"given":"Abdullah Naseer","family":"Mustapha","sequence":"first","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maitha","family":"AlMheiri","sequence":"additional","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nujood","family":"AlShehhi","sequence":"additional","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2516-7638","authenticated-orcid":false,"given":"Nitul","family":"Rajput","sequence":"additional","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sachin","family":"Joshi","sequence":"additional","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Antunes","sequence":"additional","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"AlTeneiji","sequence":"additional","affiliation":[{"name":"Technology Innovation Institute, Masdar City, Abu Dhabi P.O. Box 9639, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,7]]},"reference":[{"key":"ref_1","first-page":"151","article-title":"Tung Oil-Urea Formaldehyde Microcapsules for Anti-Corrosive Self-Healing Epoxy Coatings","volume":"3","author":"Thanawala","year":"2015","journal-title":"Mater. Sci. Surf. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e420","DOI":"10.1038\/am.2017.125","article-title":"Intrinsic Self-Healing Polymers with a High E-Modulus Based on Dynamic Reversible Urea Bonds","volume":"9","author":"Zechel","year":"2017","journal-title":"NPG Asia Mater."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.compositesb.2019.04.030","article-title":"Microcapsule-Based Self-Healing Materials: Healing Efficiency and Toughness Reduction vs. Capsule Size","volume":"171","author":"Kosarli","year":"2019","journal-title":"Compos. Part B Eng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"831","DOI":"10.1680\/macr.2010.62.11.831","article-title":"Experimental Investigation of Adhesive-Based Self-Healing of Cementitious Materials","volume":"62","author":"Joseph","year":"2015","journal-title":"Mag. Concr. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1016\/j.matchemphys.2008.02.035","article-title":"Preparation and Properties of Poly(Urea-Formaldehyde) Microcapsules Filled with Epoxy Resins","volume":"110","author":"Yuan","year":"2008","journal-title":"Mater. Chem. Phys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.proeng.2016.06.519","article-title":"Synthesis and Characterization of Urea-Formaldehyde Microcapsules Containing Functionalized Polydimethylsiloxanes","volume":"148","author":"Ullah","year":"2016","journal-title":"Procedia Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2628","DOI":"10.1166\/sam.2015.2583","article-title":"Encapsulation of Tung Oil for Self-Healing Coatings in Corrosion Applications","volume":"7","author":"Fayyad","year":"2015","journal-title":"Sci. Adv. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1108\/PRT-04-2016-0043","article-title":"Preparation and Characterisation of Melamineurea-Formaldehyde Microcapsules Containing Linseed Oil in the Presence of Polyvinylpyrrolidone as Emulsifier","volume":"46","author":"Asadi","year":"2017","journal-title":"Pigment Resin Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6650499","DOI":"10.1155\/2021\/6650499","article-title":"Evaluation of Corrosion Protection of Self-Healing Coatings Containing Tung and Copaiba Oil Microcapsules","volume":"2021","author":"Paolini","year":"2021","journal-title":"Int. J. Polym. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1016\/j.porgcoat.2017.11.019","article-title":"Fabrication of Microcapsules Containing Dual-Functional Tung Oil and Properties Suitable for Self-Healing and Self-Lubricating Coatings","volume":"115","author":"Li","year":"2018","journal-title":"Prog. Org. Coat."},{"key":"ref_11","first-page":"1","article-title":"Development of Fish Oil Microcapsules by Spray Drying Using Mesquite Gum and Chitosan as Wall Materials: Physicochemical Properties, Microstructure, and Lipid Hydroperoxide Concentration","volume":"71","year":"2022","journal-title":"Int. J. Polym. Mater. Polym. Biomater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"49536","DOI":"10.1039\/C7RA08082D","article-title":"Characterization of the Crystalline Regions of Cured Urea Formaldehyde Resin","volume":"7","author":"Liu","year":"2017","journal-title":"RSC Adv."},{"key":"ref_13","first-page":"1","article-title":"Microencapsulation by in Situ Polymerization of Amino Resins","volume":"58","author":"Nguon","year":"2017","journal-title":"Polym. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.ijadhadh.2018.10.004","article-title":"Partial Replacement of Melamine by Benzoguanamine in MUF Resins towards Improved Flexibility of Agglomerated Cork Panels","volume":"87","author":"Antunes","year":"2018","journal-title":"Int. J. Adhes. Adhes."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.eurpolymj.2018.05.037","article-title":"Highly Flexible Glycol-Urea-Formaldehyde Resins","volume":"105","author":"Antunes","year":"2018","journal-title":"Eur. Polym. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5338","DOI":"10.1016\/j.polymer.2006.05.051","article-title":"Preparation and Characterization of Poly(Urea-Formaldehyde) Microcapsules Filled with Epoxy Resins","volume":"47","author":"Yuan","year":"2006","journal-title":"Polymer"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1023","DOI":"10.3144\/expresspolymlett.2017.96","article-title":"Parametric Study for Epoxy Loaded PMMA Microcapsules Using Taguchi and ANOVA Methods","volume":"11","author":"Sharma","year":"2017","journal-title":"Express Polym. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"339","DOI":"10.14314\/polimery.2018.5.2","article-title":"Poly(Urea-Formaldehyde) Microcapsules\u2014Synthesis and Influence of Stirring Speed on Capsules Size","volume":"63","author":"Bolimowski","year":"2018","journal-title":"Polimery"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"123028","DOI":"10.1016\/j.cej.2019.123028","article-title":"Hydrocolloids: Nova Materials Assisting Encapsulation of Volatile Phase Change Materials for Cryogenic Energy Transport and Storage","volume":"382","author":"Zhang","year":"2020","journal-title":"Chem. Eng. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1016\/j.jmrt.2021.01.025","article-title":"Taguchi and ANOVA Analysis for the Optimization of the Microencapsulation of a Volatile Phase Change Material","volume":"11","author":"Mustapha","year":"2021","journal-title":"J. Mater. Res. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1080\/02652040601162699","article-title":"Investigation of Alternative Compounds to Poly(E-MA) as a Polymeric Surfactant for Preparation of Microcapsules by Phase Separation Method","volume":"24","author":"Yoshizawa","year":"2007","journal-title":"J. Microencapsul."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1007\/s40243-017-0098-0","article-title":"Preparation and Characterization of 100% Bio-Based Polylactic Acid\/Palmitic Acid Microcapsules for Thermal Energy Storage","volume":"6","author":"Fashandi","year":"2017","journal-title":"Mater. Renew. Sustain. Energy"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"31147","DOI":"10.1021\/acsomega.1c04597","article-title":"Encapsulation of Cerium Nitrate within Poly(Urea-Formaldehyde)Microcapsules for the Development of Self-Healing Epoxy-Based Coating","volume":"6","author":"Farzi","year":"2021","journal-title":"ACS Omega"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1234","DOI":"10.1016\/j.cej.2018.11.054","article-title":"Polysaccharide Assisted Microencapsulation for Volatile Phase Change Materials with a Fluorescent Retention Indicator","volume":"359","author":"Zhang","year":"2019","journal-title":"Chem. Eng. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"4015","DOI":"10.1038\/s41598-018-22445-z","article-title":"Thermochromic Microcapsules with Highly Transparent Shells Obtained through In-Situ Polymerization of Urea Formaldehyde around Thermochromic Cores for Smart Wood Coatings","volume":"8","author":"Zhu","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"719","DOI":"10.3109\/02652040309178083","article-title":"In Situ Poly(Urea-Formaldehyde) Microencapsulation of Dicyclopentadiene","volume":"20","author":"Brown","year":"2003","journal-title":"J. Microencapsul."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"353","DOI":"10.4097\/kja.d.18.00242","article-title":"What Is the Proper Way to Apply the Multiple Comparison Test?","volume":"71","author":"Lee","year":"2018","journal-title":"Korean J. Anesthesiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2303","DOI":"10.1007\/978-1-4419-9863-7_1212","article-title":"Tukey\u2019s Test","volume":"2013","author":"Haynes","year":"2013","journal-title":"Encycl. Syst. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1007\/s00289-010-0355-1","article-title":"Effect of Emulsifier on Poly(Urea-Formaldehyde) Microencapsulation of Tetrachloroethylene","volume":"67","author":"Fan","year":"2011","journal-title":"Polym. Bull."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1007\/s00289-015-1518-x","article-title":"Preparation and Characterization of Urea\u2013Formaldehyde Microcapsules Filled with Paraffin Oil","volume":"73","author":"Fayyad","year":"2016","journal-title":"Polym. Bull."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1016\/j.jmrt.2018.04.013","article-title":"Investigating the Effect of Synthesis Conditions on the Formation of Urea-Formaldehyde Microcapsules","volume":"8","author":"Katoueizadeh","year":"2019","journal-title":"J. Mater. Res. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1002\/(SICI)1097-4628(19971010)66:2<255::AID-APP6>3.0.CO;2-V","article-title":"On the Networking Mechanisms of Additives-Accelerated Phenol-Formaldehyde Polycondensates","volume":"66","author":"Pizzi","year":"1997","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"92480","DOI":"10.1039\/C5RA17666B","article-title":"Preparation and Characterization of an Azide\u2013Alkyne Cycloaddition Based Self-Healing System via a Semiencapsulation Method","volume":"5","author":"Saikia","year":"2015","journal-title":"RSC Adv."},{"key":"ref_34","first-page":"205","article-title":"TG-FTIR Study on Urea-Formaldehyde Resin Residue during Pyrolysis and Combustion","volume":"173","author":"Jiang","year":"2010","journal-title":"undefined"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Ismail, N.A., Khan, A., Fayyad, E., Kahraman, R., Abdullah, A.M., and Shakoor, R.A. (2021). Self-Healing Performance of Smart Polymeric Coatings Modified with Tung Oil and Linalyl Acetate. Polymers, 13.","DOI":"10.29117\/quarfe.2021.0051"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1016\/j.ijadhadh.2011.05.001","article-title":"Hydrolytic Stability and Crystallinity of Cured Ureaformaldehyde Resin Adhesives with Different Formaldehyde\/Urea Mole Ratios","volume":"31","author":"Park","year":"2011","journal-title":"Int. J. Adhes. Adhes."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"185","DOI":"10.3389\/fmats.2019.00185","article-title":"Preparation and Properties of Corrosion-Resistant Coatings From Waterborne Polyurethane Modified Epoxy Emulsion","volume":"6","author":"Zhang","year":"2019","journal-title":"Front. Mater."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"106558","DOI":"10.1016\/j.porgcoat.2021.106558","article-title":"Self-Healing Epoxy Coatings with Microencapsulated Ionic PDMS Oligomers for Corrosion Protection Based on Supramolecular Acid-Base Interactions","volume":"162","author":"Boumezgane","year":"2022","journal-title":"Prog. Org. Coat."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"105874","DOI":"10.1016\/j.porgcoat.2020.105874","article-title":"Preparation and Evaluation of Corrosion Resistance of a Self-Healing Alkyd Coating Based on Microcapsules Containing Tung Oil","volume":"147","author":"Pellanda","year":"2020","journal-title":"Prog. Org. Coat."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.porgcoat.2016.11.015","article-title":"Synthesis and Characterization of Poly(Urea-Formaldehyde) Microcapsules Containing Linseed Oil for Self-Healing Coating Development","volume":"105","author":"Lang","year":"2017","journal-title":"Prog. Org. Coat."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/j.porgcoat.2010.08.017","article-title":"Tung Oil: An Autonomous Repairing Agent for Self-Healing Epoxy Coatings","volume":"70","author":"Samadzadeh","year":"2010","journal-title":"Prog. Org. Coat."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/14\/9\/1907\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:07:22Z","timestamp":1760137642000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/14\/9\/1907"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,5,7]]},"references-count":41,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2022,5]]}},"alternative-id":["polym14091907"],"URL":"https:\/\/doi.org\/10.3390\/polym14091907","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,5,7]]}}}