How does emulsion, a coating substrate, play a crucial role in enhancing the anti-corrosion performance of anti-corrosion coatings?
Publish Time: 2025-11-18
Against the backdrop of a global push for green and low-carbon transformation, the anti-corrosion coating industry is accelerating its upgrade towards environmentally friendly and resource-sustainable directions. As a core additive in water-based and oil-based anti-corrosion coating formulations, emulsion, a novel coating substrate developed primarily from renewable biological resources, not only significantly improves the anti-corrosion performance of coatings but also demonstrates great potential in reducing dependence on fossil resources and lowering the carbon footprint. It acts as a "molecular-level bonding bridge," optimizing the stability, film density, and interfacial adhesion of the coating system at the microscopic level, providing key technical support for the development of high-performance green anti-corrosion coatings.1. Stable Dispersion System, Ensuring Efficient Function of Anti-corrosion Pigments and FillersThe protective efficacy of anti-corrosion coatings largely depends on the uniform dispersion and long-term stability of rust-inhibiting pigments and fillers such as zinc powder, mica iron oxide, and phosphates. Traditional emulsions are easily affected by electrolyte or pH changes, leading to pigment flocculation and sedimentation, weakening the barrier effect. Bio-based emulsions synthesized from renewable resources such as plant oils, glycosides, or lignin derivatives possess excellent interfacial activity and steric hindrance effects. They can form stable micelle structures in aqueous or oil phases, effectively encapsulating and dispersing micron/nano-sized anti-corrosion particles. This highly stable dispersion system ensures coating uniformity during application, allowing the anti-rust components to be evenly distributed within the paint film, maximizing cathodic protection or passivation corrosion inhibition.2. Promoting Dense Film Formation, Constructing a Long-Lasting Anti-Corrosion "Physical Barrier"The durability of anti-corrosion coatings hinges on their density—the fewer the pores, the more difficult it is for water vapor, oxygen, and corrosive ions to penetrate the metal substrate surface. Bio-based emulsions, by regulating the fusion behavior of polymer emulsion particles, guide the latex particles to stack tightly during film formation, reducing micropores and defects. Some modified emulsions also contain long-chain hydrophobic groups or self-crosslinking functional groups, which can participate in the film-forming reaction during drying, further enhancing the crosslinking density and hydrophobicity of the paint film. Experiments show that water-based epoxy or acrylic anti-corrosion coatings with added emulsions can reduce water vapor transmission rate by more than 30% and significantly extend salt spray test tolerance time, truly achieving long-lasting "leak-proof" protection.3. Enhanced substrate adhesion, blocking corrosion spread at the sourceEven if the coating itself is dense, if it does not adhere well to the metal substrate, corrosion can still quietly penetrate from the interface. Bio-based emulsions often incorporate polar groups such as carboxyl, hydroxyl, or phosphate groups into their molecular structure. These groups can form strong chemical adsorption or hydrogen bonding with metal surfaces such as steel and aluminum, significantly improving coating adhesion. Simultaneously, their excellent wetting properties make the coating easier to spread on rough or slightly rusted substrate surfaces, achieving effective coverage even with "rusted coatings," reducing pretreatment energy consumption. This "strong adhesion + high wetting" characteristic fundamentally cuts off the path of corrosive media diffusion along the interface.4. Green Attributes Empower Product Competitiveness Throughout its LifecycleUnlike petroleum-based emulsions, these bio-based products use non-grain crops, waste oils, or forestry byproducts as raw materials. The production process is energy-efficient, with low VOC emissions, and most are biodegradable. This not only complies with stringent environmental regulations such as EU REACH and China's Green Product Certification, but also helps coating companies build low-carbon supply chains. End users enjoy superior anti-corrosion performance while demonstrating their ESG responsibility. In sectors with increasingly stringent sustainability requirements, such as infrastructure, marine engineering, and new energy equipment, these coatings are becoming the preferred choice in the high-end market.Emulsions based on renewable resources have evolved from a traditional "auxiliary role" to a "performance engine" for green, high-performance anti-corrosion coatings. Through stable dispersion, dense film formation, and enhanced adhesion, they systematically improve anti-corrosion performance; simultaneously, their distinct environmental label gives the product a differentiated competitive advantage.
