ECO-FRIENDLY CLAY-BASE MULTIFUNCTIONAL ADDITIVE IMPROVING PAINT RESISTANCE TOWARDS DEGRADATION PROCESSES INCLUDING UV RADIATION

ABSTRACT

The paper presents studies on the development of multifunctional modified clay mineral-base additives that are used for paint, coating, resin and other finishing building material applications to improve the durability of the finishing products by protecting it from degradation processes as abrasive influence, UV radiation, moisture and microbial influence. Such swelling clay mineral as montmorillonite (smectite) is selected for the development of hydrophobic and UV protectable additive because of its specific physico-chemical properties, such as high surface area, non-toxicity and excellent adsorption ability. Modification of the selected clay minerals is carried out mechanochemically by exchanging naturally occurring inorganic cations of the mineral to alkylammonium ions. After hydrophobic mass is obtained, it is dried and grinded. Obtained organoclays additive is non-toxic and premium-cost additive that can be effectively dispersed into different binder systems, solvent and water-borne paints and other systems. The field tests that are carried out in aggressive environments confirm the improvement of the durability (less abrasive degradation and bleaching by UV radiation) and aesthetic look of finished exterior objects when organoclay additive was added to coatings matrix. It was noticed that the additive retarded algae growth on the treated exterior walls. Hypothetical explanation of such phenomenon is the expressed hydrophobicity of the organoclay additive that improves the water vapor permeability in the finished coating. It is concluded that the organoclay additives can be used in material matrix to prolong the self-life of the treated objects with potential applications in the building finishing industry.

Keywords: clay additives, organoclays, paints, UV radiation, bleaching, durability