Publication Type Journal Article
Title Hybrid shell microcapsules containing isophorone diisocyanate with high thermal and chemical stability for autonomous self-healing of epoxy coatings
Authors M. Attaei Mario Vale Abdul Shakoor Ramazan Kahraman Maria F. Montemor Ana C. Marques
Groups CSSE
Journal JOURNAL OF APPLIED POLYMER SCIENCE
Year 2020
Month June
Volume 137
Number 22
Pages
Abstract Silica-polyurea/polyuretane hybrid shell microcapsules (MCs) loaded with isophorone diisocyanate (IPDI) with long shelf-life and high thermal and chemical stability are prepared via emulsification followed by interfacial polymerization at the surface of oil droplets of the oil-in-water emulsion. The resultant MCs are aimed at self-healing performance in epoxy coatings. A commercially available, highly reactive polyisocyanate named tris(p-isocyanatophenyl) thiophosphate is successfully employed as shell forming agent, while triethoxyoctylsilane and hexadecyltrimethoxysilane (HDMS) are tested as latent active hydrogen sources. The resulting MCs display core-shell morphology, spherical shape with diameter of 5-20 mu m, shell thickness ca. 1-2 mu m, and an IPDI core fraction of 69 and 65 wt \%, when HDMS and triethoxyoctylsilane are employed, respectively. MCs exhibit an increased thermal stability, comparing with pure IPDI, which makes them robust enough to resist the thermal cycles involved in the coating s preparation. Stability of MCs inside specific solvents and chemicals, their chemical composition and shelf-life as well as effect of MCs on the epoxy curing are evaluated by Fourier transformed infrared spectroscopy. MCs, remarkably, show excellent environment stability and a long shelf-life of more than 3.5 months. Their addition to an epoxy formulation is found to heal damaged zones in the epoxy coating, as shown by scanning electron microscopy and electrochemical impedance spectroscopy. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48751.
DOI http://dx.doi.org/10.1002/app.48751
ISBN
Publisher WILEY
Book Title
ISSN 0021-8995
EISSN 1097-4628
Conference Name
Bibtex ID ISI:000499294600001
Observations
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