Self-stratifying powder coatings based on eco-friendly, solvent-free epoxy/silicone technology for simultaneous corrosion and weather protection
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
A melt-based self-stratifying coating based on silicone/epoxy blend systems is reported as an easy-to-use, ecofriendly, and industrial favorable procedure. The powder forms of the silicone and epoxy resins were mixed either by dry-blending or co-melt-mixing processing method, and blends were electrostatically applied onto steel sheets and cured. Self-stratification of cured coatings with a thickness of 100 +/- 30 pm occurred and was investigated by an adopted ATR-FTIR method and consolidated SEM-EDX and X-ray photoelectron spectroscopy. Fundamental studies on influencing parameters on phase separation and stratification in coatings such as surface tension, the mass ratio of silicone/epoxy resins, crosslinking reaction, and manufacturing processes were performed and discussed in detail. It is corroborated that the dry-blending of methyl substituent silicone resin with the high and medium molecular weight epoxy resins at a 1/3 mass ratio (silicone/epoxy) leads to a complete stratification structure (Type I), having the silicone phase located on the top of the coating and the epoxy phase towards the steel surface, resulting in good adhesion. 3/1 mass ratio of the silicone/epoxy blends led to the dispersion of epoxy droplets into the silicone matrix (Type IV) and 1/1 mass ratio, showed lateral phase separation morphology. The co-melt-mixing process was yielded the formation of a thin homogenous layer of silicone phase on the top surface of the coating and a mixture of large and small drops of silicone dispersed into the epoxy matrix (Type I-Type III). Finally, the protective properties of the silicone/epoxy self-stratifying coatings with different stratification structures were evaluated.
Details
Original language | English |
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Article number | 106443 |
Number of pages | 17 |
Journal | Progress in organic coatings |
Volume | 161 |
Early online date | Aug 2021 |
Publication status | Published - Dec 2021 |
Peer-reviewed | Yes |
External IDs
Scopus | 85112002582 |
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ORCID | /0000-0002-4531-691X/work/148608024 |
Keywords
Keywords
- Corrosion and weather protection, Epoxy resin, IR spectroscopy, Phase separation, Self-stratifying powder coatings, Silicone resin