Comparative study of CNC and CNF as additives in waterborne acrylate-based anti-corrosion coatings

Abstract

Nanocomposite coatings are of great interest as barrier coatings since synergy effects between matrix and additive properties can be achieved. This, however, requires favorable additive-matrix interactions to provide a strong interphase (interface region). In this work we elucidate the properties of two environmentally benign nanocomposite coatings based on a waterborne acrylate formulation with additives from renewable sources, i.e. either cellulose nanocrystals, CNC; or, alternatively, cellulose nanofibrils, CNF. We focus on the corrosion protective properties of these coatings and discuss the reason why the nanocomposite with CNC displays favorable corrosion protection properties whereas that with CNF does not. To this end we utilized scanning electron microscopy, water contact angle measurement, Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy techniques to investigate the microstructure, surface wetting, interactions between cellulosic materials and matrix as well as corrosion protective properties of both composite coatings.

Graphical Abstract

Keywords:

• Composite coating
• corrosion protection
• cellulose nanocrystals
• cellulose nanofibrils
• electrochemical impedance spectroscopy

Acknowledgements

China Scholarship Council (CSC) is acknowledged for financing Yunjuan He’s PhD study at KTH. PTE coatings AB Gamleby, Sweden is acknowledged for providing the polymer matrix dispersion. PhD student Gen Li at the division of surface and corrosion science, KTH is thanked for preparing silanated glass surfaces. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

Disclosure statement

No potential conflict of interest was reported by the authors.