Encapsulation of linseed oil and linseed oil based alkyd resin by urea formaldehyde shell for self-healing systems

• Published in: Progress in organic coatings 2018-08, Vol.121, p.190-200
• Main Authors: Kurt Çömlekçi, G., Ulutan, S.
• Format: Article
• Language: English
• Subjects: Aldehydes; Alkyd resin; Corrosion prevention; Design of experiments; Formaldehyde; Fourier transforms; Linseed oil; Microcapsule; Microencapsulation; Morphology; Oil; Optical microscopy; Organic chemistry; Oxidation; Parameters; Protective coatings; Resins; Response surface methodology; Self healing materials; Self-healing system; Stirring; Surfactants; Thermodynamic properties; Urea formaldehyde resins; Urea-formaldehyde
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2018.04.027

•Linseed oil and its alkyd resin were successfully encapsulated in PUF resin.•The surfactant amount (20–60 ml) and stirring rate (800–1500 rpm) are the parameters.•Capsule size distribution and morphology were dependent on the parameters above.•Microcapsule wall thickness is affected by the parameters for both healing agents.•The capsules are expected to be a prospective material for a self healing coating. In the present study, linseed oil based alkyd resin and linseed oil have been encapsulated to propose the alkyd resin as a prospective material for being used in epoxy coating system for corrosion protection through self-healing. The superiority of the present systems as Linseed oil and its alkyd resin evolves from the utilization of the environmentally friendliness thanks to their film formation by auto-oxidation. The encapsulation of healing agents by means of in-situ polymerization of urea formaldehyde has been studied with the parameters as the amount of surfactant and the rate of stirring. The experimental design has been modeled by using Response Surface Method to investigate the effect of surfactant (poly(vinyl alcohol), PVA) amount and stirring rate effect on the microcapsules (MC) size. Optical microscopy has been utilized to follow the reaction and size change of MCs. The chemical structure, thermal properties and capsule morphology has been illuminated by using FTIR spectroscopy, TGA and SEM analysis, respectively. The capsules obtained have had 51 and 56 μm diameter at high levels of the parameters (60 ml PVA, 1500 rpm stirring rate) and 97 and 261 μm diameter at low levels of the parameters (20 ml PVA, 800 rpm stirring rate) for LO and LO-Alkyd respectively.