Open AccessSelf-Healing Epoxy Coating with Microencapsulation of Linseed Oil for the Corrosion Protection of Magnesium (Mg)
Author(s) -
J. Alias,
Norhasnidawani Johari,
A. Zanurin,
N. A. Alang,
Malaysia Zain
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2129/1/012008
Subject(s) - materials science , corrosion , coating , polyurea , magnesium , tafel equation , epoxy , linseed oil , composite material , self healing , scanning electron microscope , metallurgy , electrochemistry , chemistry , electrode , medicine , alternative medicine , organic chemistry , pathology
The ability to self-heal is an important feature for the long-term durability of protective coatings on metal alloys. Microcapsules in the self-healing coating allowed for automatic recovery of any damages or cracks, extending the life of the coating. In this study, self-healing microcapsules containing linseed oil as the core material and polyurea-formaldehyde (PUF) as the shell material were manufactured to epoxy resin matrix. Coatings were applied to a bare magnesium (Mg) substrate and scratched to test the self-healing ability. Optical and scanning electron microscopy (SEM) were used to characterize the microcapsules formed by varied stirring rates of 300 and 800 rpm. By using potentiodynamic polarization in a 3.5 wt.% NaCl solution, the corrosion rate of embedded microcapsules and coatings on Mg was evaluated, and the corrosion rate was studied using the Tafel plot. As a consequence, the epoxy coating containing linseed oil and urea formaldehyde, stirred at 800 rpm, significantly resists corrosion attack on the magnesium sheet, with decreased corrosion current density, icorr (1.552 μA/cm 2 ) as compared to the bare magnesium sheet (109.8 μA/cm 2 ). During the microcapsule preparation, increasing the stirring rate from 300 to 800 rpm reduces the icorr value by roughly half. As a result, the self-healing coatings demonstrated adequate self-healing and corrosion resistance recovery on magnesium alloys.