Improved performance of aluminum pigments encapsulated in hybrid inorganic

Pi, P., Liu, C., Wen, X., Zheng, L., Xu, S., & Cheng, J. (2015). Improved performance of aluminum pigments encapsulated in hybrid inorganic–organic films. Particuology, 19, 93–98. https://doi.org/10.1016/j.partic.2014.05.010

Improved performance of aluminum pigments encapsulated in hybrid inorganic–organic films

Pihui Pi, Chao Liu, Xiufang Wen, Lianfu Zheng, Shouping Xu^*, Jiang Cheng

School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China

10.1016/j.partic.2014.05.010

Volume 19, April 2015, Pages 93-98

Received 3 March 2014, Revised 28 April 2014, Accepted 7 May 2014, Available online 8 October 2014.

E-mail: cespxu@scut.edu.cn

Highlights

• An organic silane acrylate resin (PMBK) was synthesized by free-radical solution polymerization.

• Al particles were encapsulated in inorganic–organic films with PMBK and TEOS via one-step process.

• An organic silane monomer was used because of its higher copolymerization capacity.

• PMBK-SiO₂/Al exhibited better anticorrosion performance while retaining its glossiness.

• Adhesive performance of Al particles in paint films with PMBK-SiO₂/Al was better than that with SiO₂/Al and raw Al.

Abstract

An organic silane acrylate resin (PMBK) was synthesized by free-radical solution polymerization using methyl methacrylate, butyl acrylate and (3-methacryloxypropyl)trimethoxysilane as monomers. Aluminum (Al) particles were then encapsulated in inorganic–organic hybrid films that were prepared by hydrolysis and condensation of PMBK and tetraethyl orthosilicate (TEOS) on the surface of Al pigments. Characterization results showed that PMBK and TEOS could simultaneously hydrolyze and condense with hydroxyl groups on the surface of the Al particles to form composite Al particles coated with inorganic–organic hybrid films. Compared with raw Al particles, the corrosion resistance and adhesive properties of paint films containing the composite Al particles were improved greatly, while the glossiness of the paint films decreased slightly, from 48.6° to 47.0°. In alkaline media (pH 11), the volume of evolved H₂ of composite Al particles was only 3.5 mL, whereas that of raw Al was 83.5 mL. The glossiness of paint films containing composite Al particles decreased by 1.66% after immersion in alkaline media for 24 h, whereas that of raw Al decreased by 14.82%. Peel-off tests of the paint films showed that the composite particles moved slightly away from the paint films. In contrast, the raw Al particles were seriously desquamated, suggesting encapsulation of hybrid films can greatly improve the adhesive properties of Al particles in paint films.

Graphical abstract

Keywords

Aluminum pigments; Inorganic–organic hybrid encapsulation; Corrosion resistance; Adhesive performance; Glossiness

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