A review on plant extracts as natural additives in coating applications

Abstract

Coating is a layer of substance that covering and protecting the substrate surface from exposure to the environment. Acrylic and epoxy resins are the most used polymer resins for coating applications. However, neat polymer coatings without any pigments or additives are not enough to protect the surface of the substrate due to some disadvantages. Thus, additives will be added into the polymer resins to enhance the properties of the coating and protect the substrates. Most industries use inorganic additives in coating applications. They show excellent properties for the coating, and they can enhance the protection of the substrates. However, they consist of heavy metals that are toxic and harmful to human and environment. Nowadays, researches are more focusing on using plant extracts as the natural additives for coating applications. Plant extract (natural additives) have the same functions as the synthetic additives, and they are non-toxic, environment friendly and safe to be used. Besides, researches also discovered that plant extracts consist of functional properties such as anti-corrosion, antimicrobial, antifouling, self-healing and UV-shielding abilities which make them qualify to use as natural additives in coating applications.