Influence of PMVEMA-ES and 4-hydroxycoumarin hydrazone dyes on the physico-optical properties of PMMA coating films

Organic translucent coatings with high glossiness and homogeneous colour distribution are highly sought due to their aesthetic properties. The application of such organic coatings on glass substrates such as mirrors and windows will not only to protect these surfaces from damage, but also as decorative purpose. Herein, the work described the preparation of translucent poly(methyl methacrylate), PMMA-based coatings on glass surfaces. Since PMMA has low adhesion ability onto glass, poly(methyl vinyl ether-alt-maleic acid monoethyl ester), PMVEMA-ES is proposed as an additive to promote the adhesion of PMMA onto glass surfaces. Various 4-hydroxycoumarinhydrazone derivatives (CADs) were used as dyes. The physical, optical, and thermal properties of the prepared coatings were investigated and correlated. The addition of PMVEMA-ES and CAD dyes altogether enhanced the adhesion of PMMA onto glass surfaces, as evidenced from cross-hatch adhesion tests, supported with TGA and DSC results. The presence of substituents has limited influence on the optical properties of coatings. The dyes have also contributed to the overall increased in coating glossiness, especially when alkyl groups were present in the dye. Moreover, the CAD dyes can be good candidates as colourants for translucent coating films as they have low coating opacity and high (> 90%) transmittance beyond 500 nm.