Publication detail
Self-healing epoxy coating synthesis by embedment of metal 2-methyl imidazole and acetylacetonate complexes with microcapsules
Ullah, H. Qureshi, K.S. Khan, U. Zaffar, M. Yang, Y.J. Rabat, N.E. Khan, M.I. Saqib, S. Mukhtar, A. Ullah, S. Mubashir, M. Bokhari, A. Chai, W.S. Chew, K.W. Show, P.L.
English title
Self-healing epoxy coating synthesis by embedment of metal 2-methyl imidazole and acetylacetonate complexes with microcapsules
Type
journal article in Web of Science
Language
en
Original abstract
The restoration of mechanical properties is desired for creating the self-healing coatings with no corrosion capabilities. The encapsulation of epoxy resins is limited by various factors in urea and melamine formaldehyde microcapsules. An improved method was developed, where epoxy resin was encapsulated by individual wrapping of poly(melamine-formaldehyde) and poly(urea-formaldehyde) shell around emulsified epoxy droplets via oil-in-water emulsion polymerization method. The synthesized materials were characterized analytically. The curing of the epoxy was achieved by adding the [Ni/Co(2-MI)(6)]center dot 2NO(3) as a latent hardener and iron acetylacetonate [Fe(acac)(3)] as a latent accelerator. Isothermal and non-isothermal differential scanning calorimetric analysis revealed lower curing temperature (T-onset = 116 degrees C) and lower activation energies (Ea approximate to 69-75 kJ/mol). The addition of microcapsules and complexes did not adversely alter the flexural strength and flexural modulus of the epoxy coatings. The adhesion strength of neat coating decreased from 6310.8 +/- 31 to 4720.9 +/- 60 kPa and percent healing increased from 50.83 to 67.45% in the presence of acetylacetonate complex at 10 wt% of microcapsules.
English abstract
The restoration of mechanical properties is desired for creating the self-healing coatings with no corrosion capabilities. The encapsulation of epoxy resins is limited by various factors in urea and melamine formaldehyde microcapsules. An improved method was developed, where epoxy resin was encapsulated by individual wrapping of poly(melamine-formaldehyde) and poly(urea-formaldehyde) shell around emulsified epoxy droplets via oil-in-water emulsion polymerization method. The synthesized materials were characterized analytically. The curing of the epoxy was achieved by adding the [Ni/Co(2-MI)(6)]center dot 2NO(3) as a latent hardener and iron acetylacetonate [Fe(acac)(3)] as a latent accelerator. Isothermal and non-isothermal differential scanning calorimetric analysis revealed lower curing temperature (T-onset = 116 degrees C) and lower activation energies (Ea approximate to 69-75 kJ/mol). The addition of microcapsules and complexes did not adversely alter the flexural strength and flexural modulus of the epoxy coatings. The adhesion strength of neat coating decreased from 6310.8 +/- 31 to 4720.9 +/- 60 kPa and percent healing increased from 50.83 to 67.45% in the presence of acetylacetonate complex at 10 wt% of microcapsules.
Keywords in English
Adhesion strength; Epoxy resins; Flexural strength; Melamine-urea-formaldehyde; Metal imidazole complex; Self-healing
Released
01.12.2021
Publisher
Elsevier Ltd.
Location
PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
ISSN
0045-6535
Number
285
Pages from–to
131492–131492
Pages count
12
BIBTEX
@article{BUT172195,
author="Syed Awais Ali Shah {Bokhari},
title="Self-healing epoxy coating synthesis by embedment of metal 2-methyl imidazole and acetylacetonate complexes with microcapsules",
year="2021",
number="285",
month="December",
pages="131492--131492",
publisher="Elsevier Ltd.",
address="PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND",
issn="0045-6535"
}