Effect of addition of clay minerals on the properties of epoxy/polyester powder coatings

Abstract

Powder coatings have been used for coating metal substrates in industrial applications. The incorporation of nanofillers as muscovite mica and montmorillonite (MMT) can improve the properties of the coatings. The objective of this study is to develop, apply and characterize a hybrid powder coating (30% epoxy/70% polyester) adding nanofillers in concentrations of 2, 4 and 6 phr separately in a twin screw extruder. The characterization of the coatings was performed by thermal, mechanical and chemical analysis. The incorporation of clay into the polymer increased the surface roughness resulting in a diffuse reflection of incident light and on a gloss reduction. The muscovite mica presented a lamellar structure, constituted by a set of overlapping parallel plates. The morphology analysis showed that the MMT presented irregular agglomerates resulting in inferior mechanical properties to coatings with muscovite mica. In the salt spray test, all samples showed high corrosion protection, around 850 hours.

Sustainable Composites Based on Recycled High-density Polyethylene/mica

“…In this work, we observed no chemical interaction between the rHDPE and mica. Other authors have reported they also did not observe a band indicating covalent bonding between polymer and filler, attributing this to the presence of physical interactions [15][16][17][18] .…”

“…The magnification of the region closest to the melt peak (Figure 7), between 130-150 o C, revealed that the rHDPE/mica samples had slightly lower melting temperatures compared to the rHDPE. This can be also related to the presence of agglomerates and lack of dispersion, as indicated by the DTG results 17,18 . However, considering the results already discussed, which indicate the reinforcement action of mica, these results indicate the interaction between the mineral and the polymer is physical, as also observed by FTIR.…”

“…The DTG peaks ( Figure 5) showed a slight difference in the decomposition rate, which became slower with higher proportion of mica in the composite. Melo et al and with the presence of agglomerates and inefficient dispersion of the fillers, suggesting the need to use a coupling agent 17,18 . As seen in Table 2, analysis of the thermal profile of r-HDPE indicated a final residue percentage of about 2.5%, corresponding to additives incorporated in the material, such as dyes and compatibilizers 3,4 .…”

Preparation of Shellac Resin Microcapsules Coated with Urea Formaldehyde Resin and Properties of Waterborne Paint Films for Tilia amurensis Rupr.

“…The reason may be that the microcapsules were in the form of powder. When the concentration of microcapsules increased, the particles may have also increased, and the particles would have formed small bumps on the surface of the paint film, which would cause light scattering on the corresponding paint film surface, thus reducing the intrinsic gloss of the paint film [24]. The gloss change of paint film can be reflected by irradiating paint film with the same intensity of light from a 60 • incident angle.…”

High performance epoxy/polyester-based nanocomposite coatings for multipurpose applications: A review

“…7 Consequently, advanced coatings based on epoxy and polyester have been developed for industrial structures and systems. 8 The epoxy/polyester coatings have shown excellent anti-fouling and anti-corrosion behaviors. The epoxy/polyester blend can form physically and covalently cross-linked structures with enhanced thermal, mechanical, and water resistance.…”