Potassium oleate is a potassium catalyst which is mainly used as a catalyst for the reaction of polyisoprene in polyurethane foam. It can also be used as an emulsifier, a detergent, and the like — appearance and traits: brown stable or transparent to amber liquid.
Melting point: 235 - 240oC. Boiling point: 360oC at 760 mmHg.
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Oleic acid is a liquid with a carboxyl-COOH at the end of the long chain. The potassium is directly put into the oleic acid, and a displacement reaction occurs to generate hydrogen and potassium oleate. The saponification method is mainly used in the industry. Oils such as butter and sheep oil are saponified with potassium hydroxide and are obtained by salting out and Separating glycerin.
The direct reaction of potassium metal with oleic acid is a laboratory-scale method that is rarely used industrially due to the hazards associated with handling reactive potassium metal and the explosive nature of hydrogen gas generated during the reaction. Industrial production predominantly relies on the saponification of natural oils and fats. Triglycerides—esters of glycerol with three fatty acid molecules—react with potassium hydroxide (KOH) in a process known as alkaline hydrolysis or saponification. This reaction breaks the ester bonds, releasing glycerol as a by-product and forming potassium salts of the fatty acids. The resulting mixture is then separated through salting-out or distillation to isolate the potassium oleate from glycerol and other fatty acid salts. This approach is preferred because natural oils contain a mixture of fatty acids, and oleic acid is typically the predominant component, making this route both economical and efficient.
1. Calculate the MOL ratio of about 1:1.1 = oleic acid: potassium hydroxide.
2. KOH is dissolved to 20% concentration and heated to about 80 degrees.
3. Add oleic acid slowly after stirring.
4. Continue cooking after the addition; the temperature rises to the near-boiling point.
5. The reaction is completed. That is a potassium oleate solution.
Reaction Mechanism
The formation of potassium oleate from oleic acid and potassium hydroxide is a classic acid-base neutralization reaction. Oleic acid (C₁₇H₃₃COOH) donates a proton (H⁺) to the hydroxide ion (OH⁻) from potassium hydroxide, forming water and the potassium oleate salt (C₁₇H₃₃COOK). The reaction can be represented by the following equation:
C₁₇H₃₃COOH + KOH → C₁₇H₃₃COOK + H₂O
The resulting potassium oleate molecule consists of a long hydrophobic hydrocarbon tail (C₁₇H₃₃) and a hydrophilic ionic head (-COOK). This amphiphilic structure is responsible for its surface activity: in aqueous solutions, the molecules align at interfaces, with the hydrophobic tails directed away from water and the hydrophilic heads directed toward water. This alignment reduces the surface tension of the liquid and stabilizes the interfaces between immiscible phases, enabling emulsification and dispersion. The surface-active properties of potassium oleate are influenced by the degree of unsaturation in the fatty acid chain, with the cis double bond in oleic acid introducing a kink that enhances fluidity and emulsifying performance.
Reaction Mechanism in Polyurethane Foam
Potassium oleate serves as a trimerization catalyst in polyurethane foam production, specifically promoting the isocyanurate ring formation reaction. During the production of polyisocyanurate (PIR) foams, potassium oleate facilitates the cyclotrimerization of isocyanate groups, resulting in the formation of stable isocyanurate rings that impart excellent thermal stability, dimensional stability, and fire retardancy to the final foam product. The catalyst is typically used in combination with other catalysts, such as tertiary amines and organotin compounds, to achieve a balanced reaction profile that optimizes both the blowing reaction (generating carbon dioxide for cell formation) and the curing reaction (crosslinking and polymer network formation). The potassium ion acts as a coordination center that facilitates the nucleophilic attack of the isocyanate groups, while the oleate anion provides solubility in the polyol-isocyanate mixture. This dual functionality contributes to its effectiveness as a catalyst and explains its widespread use in the rigid foam insulation industry, particularly in the production of construction panels, refrigerated containers, and pipe insulation.
Saponification Production Process of Potassium Oleate
Classification
Potassium oleate can be classified according to their useful content. At present, most of the market has a potassium oleate content of about 30%, but according to different market requirements, if the content is continuously increased, its state will also change, such as potassium oleate content. When it exceeds 80%, it becomes a paste, and if it is high, it will become stable, for example, a block or powder. At the same time, according to the specific requirements, it can also produce environmentally friendly potassium oleate solution such as colorless and low odor.
The classification of potassium oleate by active content reflects the diverse needs of different industries. Lower concentration solutions (20–40%) are typically used in liquid formulations such as cleaning agents and emulsifiers, where ease of handling and dosing are important. Mid-range concentrations (40–70%) are utilized in industrial applications requiring higher active content without the handling difficulties of solid forms. High-concentration pastes (80–90%) and solid forms (flakes or powders) offer advantages in transportation, storage, and product formulation flexibility, particularly for customers seeking to reduce shipping costs and formulate their own desired concentrations. Environmentally friendly grades are manufactured with reduced odor profiles, lighter color, and lower residual glycerol content, making them suitable for high-end cosmetic and personal care applications where product appearance and consumer acceptance are critical. Additionally, the degree of oxidation and the presence of unsaturated bonds can be controlled during production to enhance oxidative stability and shelf life.
Molecular Structure of Potassium Oleate
Use
Used as an emulsifier and cleaning agent. Used in creams and shampoos. It has high emulsifying efficiency, but it is easy to form calcium soap in case of hard water. It can also be used as a fiber softener.
It is a potassium catalyst and is widely used in polyisocyanate foam reactions.
Key Uses of Potassium Oleate
1. Emulsifier and Surfactant: In cosmetics, food processing, and industrial applications, potassium oleate stabilizes emulsions, ensuring consistent product quality and preventing phase separation. It is particularly effective in oil-in-water emulsions for creams, lotions, and sauces.
2. Cleaning Agent: It acts as a detergent and cleaning agent in both household and industrial products, effectively removing oil, grease, and dirt from surfaces. Its mild nature makes it suitable for use in personal care products such as facial cleansers, shampoos, and body washes. However, its sensitivity to water hardness means it is often combined with water softeners or used in formulations designed for soft water environments.
3. Catalyst: As a potassium catalyst, it is integral to the production of polyurethane foams, especially PIR foams. Its role in catalyzing the trimerization reaction is essential for achieving the high thermal resistance and fire safety standards required in the construction and transportation industries.
4. Lubricant: It serves as a lubricant in certain plastic processing and metalworking applications, improving flowability and reducing friction between surfaces. Its surfactant properties also aid in the dispersion of fillers and pigments in polymer composites.
5. Preservative: In some formulations, potassium oleate helps to inhibit the growth of mold and bacteria due to its antimicrobial properties, contributing to product preservation and extending shelf life.
6. Fiber Softener: In the textile industry, it is used as a fiber softener to impart a soft, smooth feel to fabrics, improving comfort and handling characteristics.
Main Application Fields of Potassium Oleate
TRUNNANO (Luoyang Trunnano Tech Co., Ltd ) is a professional potassium oleate manufacturer with over 12 years experience in chemical products research and development. If you are looking for high quality potassium oleate, please feel free to contact us and send an inquiry.
