Sodium Oleate CAS 143-19-1: Uses, Specs & Supply Guide
Sodium Oleate (CAS 143-19-1) is a common fatty acid salt-type anionic surfactant raw material, frequently used in industrial systems for wetting, emulsification, dispersion, cleaning, foaming, and interface control. For formulations and processes, it belongs to the category of “common but condition-sensitive” raw materials: even for the same “Sodium Oleate”, different sources and batches may show perceptible differences in appearance, dissolution behavior, system stability, foam morphology, and filterability.
What exactly is Sodium Oleate and why is it useful in many systems?
When purchasing and selecting types, which quality indicators are worth your close attention?
When encountering turbidity, precipitation, agglomeration, abnormal foam, or effect fluctuations during use, where should troubleshooting start for the fastest results?
How to turn “usable” into “long-term stable availability“.
This article will expand on the above issues item by item
Table of Contents
- Part 1: Re-recognizing Sodium Oleate (Basic Profile and Chemical Logic)
- Part 2: Core Procurement Decision—How to Read COA and Key Quality Indicators
- Part 3: Deep Application Scenarios and Formulation Suggestions
- Part 4: Practical Troubleshooting
- Part 5: Horizontal Comparison with Competing Products (Helping You Select)
- Part 6: Supply Chain Perspective—Packaging, Storage, and Transportation
- Part 7: Frequently Asked Questions (FAQ)
- Part 8: How to Start Cooperation?
- Our Laboratory and References
Part 1: Re-recognizing Sodium Oleate (Basic Profile and Chemical Logic)
1.1 Basic Product Profile
| Product Name | Sodium Oleate |
| Common Synonyms (for search) | Oleic acid sodium salt / Sodium salt of oleic acid |
| CAS No. | 143-19-1 |
| EINECS No. | 205-591-0 |
| Molecular Formula | C18H33NaO2 |
| Chemical Family | Anionic Surfactant / Fatty Acid Salt / Carboxylate |
Source of Main Component: Usually derived from oleic acid obtained after hydrolysis of natural oils (such as olive oil, palm oil, tallow, etc.) and then saponified with sodium hydroxide; it may also come from industrial-grade oleic acid fractions separated by distillation or other fatty acid sources. Specifics are subject to the supplier’s fatty acid composition and traceability documents.
Common Usage Keywords: Surfactant, Emulsifier, Wetting, Dispersion, Foaming, Interface control.
1.2 How does Sodium Oleate work?
The core reason why Sodium Oleate is “versatile” in so many industries lies in the fact that it is a typical “amphiphilic molecule“.
Hydrophilic End (Head): Carboxylate sodium salt part. It has hydrophilicity and tends to distribute in the water phase or water interface.
Lipophilic End (Tail): Long C18 carbon chain (oleic acid chain). It has lipophilicity and tends to combine with oil phases, organic solvents, or adsorb on the surface of hydrophobic solids.
When it enters your system, what is it doing?
At the water-oil interface
On solid surfaces
In the cleaning process
At the water-oil interface
At the water-oil interface: It acts like a bridge, with the head pulling water and the tail inserting into oil, thereby reducing the tension of the oil-water interface and allowing two originally immiscible phases to form a stable emulsion (Emulsification).
On solid surfaces
On solid surfaces: For example, in mineral flotation, its hydrophobic tail will adsorb on the surface of specific ores, making the ores “fear water” (hydrophobic), so they can attach to air bubbles and float up (Collection/Collector action).
In the cleaning process
In the cleaning process: Its tail inserts into oil stains, and the head stays in water. Through external stirring, the oil stains are “rolled” off the object surface and wrapped in water (Detergency and Solubilization).
1.3 Common Physical Forms: Powder vs. Granule vs. Paste
As a supplier, we are often asked: “What does your Sodium Oleate look like?” In fact, the form of Sodium Oleate determines the convenience of feeding.
Powder: Fastest dissolution speed, large specific surface area. But the disadvantage is that it is easy to generate dust, and the risk of moisture absorption and caking is greatest in humid environments. Suitable for factories requiring rapid dissolution and possessing good dust removal equipment.
Granule/Flake: To improve fluidity and reduce dust, some processes make it into granules. Dissolution speed is slightly slower, but handling is more user-friendly, and it is not easy to block the discharge port.
Paste/Gel: High-concentration Sodium Oleate will form a gel structure in water. Unless there is a special customization requirement, raw materials are usually delivered in solid form to reduce the cost of transporting water.
| Form | On-site Usage Experience | Common Advantages | Common Attention Points | More Suitable Scenarios (Examples) |
|---|---|---|---|---|
| Powder | Fastest dissolution, but easy to dust | Large specific surface area, good dispersion effect | Moisture caking, feeding dust, metering errors | Factories with good dust removal and mixing conditions |
| Granule/Flake | Feeding is smoother, less likely to block | Low dust, good fluidity, friendly operation | Slightly slower dissolution, affected by mixing conditions | Automatic feeding, sites valuing operation stability |
| Paste/Gel | Concentration adjustment needed, stirring required | No dust trouble, easy to pump/meter (depending on form) | Easy to form gel structure, requires shear mixing | Scenarios with special customization needs or high concentration use |
Part 2: Core Procurement Decision—How to Read COA and Key Quality Indicators
Many customers only ask “What is the purity?” when inquiring. However, in practical applications, what causes production accidents is often not the main content, but those ignored “secondary indicators”. As a supplier, we suggest you focus on the following parameters.
2.1 Assay
2.2 Free Alkali and Free Acid
2.3 Moisture / Loss on Drying
2.4 Insoluble Matter
2.5 Iodine Value
2.1 Assay
High Purity/Reagent Grade: Commonly 97–99% (Dry basis).
Industrial Grade: Commonly controlled by effective content/fatty acid composition, different forms and indicator systems like 65–90% oleic or 30–70% active may appear.
Significance: Determines how much “effective working” component there is.
Misconception: Higher purity is not always better. Ultra-high purity Sodium Oleate (Analytical Reagent grade) has extremely high costs and is usually used for biochemical research. In most industrial applications, what is more critical is “Effective Content/Fatty Acid Composition + Batch Fluctuation Control“, rather than the limit purity of a single test; it is recommended to write key indicators into the purchase specifications and use the batch consistency of the COA as the basis for acceptance.
2.2 Free Alkali and Free Acid
This is an indicator reflecting the “degree of reaction completeness“.
Excessive Free Alkali: Means the product pH is high and alkalinity is strong. It may cause corrosion or irritation in certain pH-sensitive formulations (such as aluminum cleaning, daily chemical/skin contact formulations, etc.).
Excessive Free Acid: Means there is more unreacted oleic acid. This will lead to increased turbidity after dissolution, easy oil floating, and easy oxidation and yellowing during long-term storage.
Our Control Strategy: It is recommended to clarify the control basis of free alkali and free acid in the purchase specifications (e.g., Free Alkali % calculated as NaOH, Free Acid % calculated as Oleic Acid, or Acid Value/Base Value range), and use COA batch stability as the basic condition for formulation stability.
2.3 Moisture / Loss on Drying
Status Quo: Sodium Oleate absorbs moisture extremely easily. Moisture is recommended as a key acceptance item and the limit and test method (such as LOD conditions) should be clarified in the purchase specifications.
Risk: High moisture not only brings “effective content conversion deviation”, but the more common engineering risks are caking, poor fluidity, unstable automatic feeding, and easier occurrence of local gel/”fish-eye” phenomena during dissolution.
Procurement Suggestion: Be sure to confirm the supplier’s inner liner moisture protection, sealing method, and storage/transportation moisture protection measures, and seal/recover/dispense as soon as possible after arrival.
2.4 Insoluble Matter
Phenomenon: Small white points or black points in the aqueous solution after dissolution.
Impact: For spray cleaning (nozzle blockage risk), precision coating, or high-transparency liquid systems, insoluble matter is a high-risk indicator needing stricter control; for flotation or rough processing systems, it can be moderately relaxed according to working conditions. It is recommended to clarify the testing parameters of “insoluble matter” (such as dissolution concentration/temperature, standing time, filter pore size or filter paper specifications, measurement unit, and judgment method).
Supplier Perspective: Different grades of products have different filtration processes and prices. Please inform us of your application scenario during inquiry, and we will recommend the matching filtration level.
2.5 Iodine Value
Significance: Reflects the number of “double bonds (unsaturated bonds)” in the molecular structure. The key distinction between Sodium Oleate and Sodium Stearate lies in this double bond.
Impact: If the Iodine Value is within the target range, it usually indicates that the system unsaturation and C18:1 components are at the expected level; generally beneficial for dissolution and low-temperature performance, but still needs comprehensive evaluation combined with fatty acid composition and low-temperature dissolution tests. If the Iodine Value is too low, it usually means the fatty acid composition shifts towards a more saturated direction (e.g., equal proportion increase of stearic acid), which may bring worse low-temperature dissolution and fluidity.
Part 3: Deep Application Scenarios and Formulation Suggestions
To help you better assess whether Sodium Oleate is suitable for your project, we will disassemble it from four main industrial sectors.
3.1 Mineral Flotation and Beneficiation
3.2 Industrial Cleaning and Metalworking Fluids
3.3 Emulsion Polymerization and Latex Industry
3.4 Construction and Waterproofing Materials
3.1 Mineral Flotation and Beneficiation
This is one of the typical application scenarios for Sodium Oleate, especially for oxide ores and salt minerals (such as hematite, apatite, fluorite, barite, etc.).
Its Role: Anionic Collector.
Mechanism: Oleate ions attach to the mineral surface through chemical adsorption or electrostatic adsorption, making it hydrophobic.
Common Pain Points: Under low temperature or hard water conditions, dissolution/dispersion and interface behavior may change, leading to fluctuations in collection performance.
Supplier Suggestions:
Compound Use: In low-temperature environments, it is recommended to compound Sodium Oleate with surfactants that have better solubility, or perform pre-heating dissolution.
Hard Water Softening: Calcium and magnesium ions in the flotation medium will consume Sodium Oleate to form precipitates (calcium soap/magnesium soap), reducing reagent efficacy. It is recommended to soften water first or add dispersants.
3.2 Industrial Cleaning and Metalworking Fluids
Its Role: Cleaning agent, lubricant, rust inhibitor.
Advantages:
Lubricity: Long carbon chain gives it excellent boundary lubrication ability, often used in wire drawing powder and cutting fluids.
Rust Prevention: Adsorbs on metal surfaces to form a hydrophobic film, providing inter-process rust protection.
Usage Restrictions: Avoid use in strong acid environments; under acidic conditions, Sodium Oleate will be acidified to generate oleic acid, which may cause turbidity, demulsification, or oil precipitation, leading to system failure or performance fluctuation.
3.3 Emulsion Polymerization and Latex Industry
In synthetic rubber (such as SBR) or certain polymer dispersions, Sodium Oleate acts as an emulsifier.
Its Role: Control latex particle size and maintain stability during polymerization.
Key Requirements: Tolerance to electrolytes and inorganic ion impurities is usually low. It is recommended to clarify control items such as key ions/conductivity in purchase specifications, and verify their impact through small-scale/pilot tests; select custom high-purity or low-salt versions if necessary.
3.4 Construction and Waterproofing Materials
Its Role: Hydrophobic agent.
Application: Added to mortar or concrete, utilizing its reaction with calcium ions to generate insoluble calcium soap-type hydrophobic substances, reducing capillary water absorption and improving anti-permeability performance.
Advantages: Low cost; under suitable dosage and working conditions, it can provide relatively stable hydrophobicity/anti-permeability improvement effects. It is recommended to verify with target standard tests.
Part 4: Practical Troubleshooting
When problems occur on-site, it is not recommended to attribute the cause to unqualified raw materials immediately. Based on our past technical support experience, many fluctuations are closely related to process conditions (temperature, water quality, feeding sequence, shear strength, pH drift, etc.). The following are common ideas and rapid verification methods for on-site troubleshooting.
Possibility A (Concentration Issue): Sodium Oleate forms liquid crystal phases or gels at high concentrations, appearing turbid or viscous.
Check: Dilute 10 times to see if it becomes clear.
Possibility B (Temperature Issue): When the temperature is lower than its Krafft point or enters the liquid crystal/gel phase in a specific concentration range, apparent solubility and transparency may decrease.
Check: Phase behavior causing turbidity/gel may occur at low temperatures or high concentrations; it is recommended to gradually increase temperature (e.g., 25→35→45°C) and record turbidity changes to distinguish temperature phase behavior from hard water precipitation.
Possibility C (Water Quality Issue): Tap water or well water was used, and calcium/magnesium ions in the water reacted with Sodium Oleate to generate white calcium/magnesium soap precipitates.
Check: Use deionized water/distilled water for testing. If it becomes clear, it is a water quality issue.
Possibility D (High Free Acid in Raw Material): Unreacted oleic acid in the raw material causes opalescence.
Check: Add a little liquid alkali to adjust pH to 9-10. If it becomes obviously clear, it can be preliminarily judged that turbidity is related to high free acid/system acidification.
Cause: System pH may drift over time (e.g., absorbing CO₂ from air or introducing acidic substances), causing part of the Sodium Oleate to be acidified into oleic acid, thereby triggering stratification or oil floating.
Solution: Choose appropriate alkalinity reserve or buffer systems according to the system, maintain the pH window allowed by the process, and combine sealed storage and water quality control to reduce drift risks.
Cause: Temperature affects micelle behavior and foam generation/stability; meanwhile, water hardness, electrolytes, pollutant load, and compound system changes will also significantly affect foam performance.
Solution: It is recommended to do comparative small-scale tests under fixed shear and fixed water quality conditions to confirm temperature sensitivity; fine-tune foam stabilizers/defoamers or compound systems to adapt to seasonal fluctuations if necessary.
Cause: Pouring too fast at once, the outer layer of powder absorbs water to form a gel layer, wrapping the internal dry powder (commonly known as “fish-eye” phenomenon).
Solution:
Switch to warm water for dissolution.
Adopt the “scattering method” to add slowly while maintaining stirring.
Pre-wet the powder with a small amount of ethanol or glycerin before adding to water.
Part 5: Horizontal Comparison with Competing Products (Helping You Select)
In the initial procurement selection stage, many customers struggle: Should I use Sodium Oleate, Sodium Stearate? Or Potassium Oleate? The following comparison table helps you decide quickly.
| Comparison Dimension | Sodium Oleate | Sodium Stearate | Potassium Oleate | Oleic Acid |
|---|---|---|---|---|
| Chemical Structure | C18, with double bond (unsaturated) | C18, no double bond (saturated) | C18, with double bond | Acid form, non-salt |
| Water Solubility | Good (better in warm water) | Poor (requires high temp dissolution) | Excellent (soluble in cold water) | Insoluble in water |
| Low Temp Performance | Relatively good, but turbidity/thickening/phase separation may still occur at low temp | Poor, easy to solidify | Extremely good, cold resistant | / |
| Main Function | Cleaning, Emulsification, Flotation | Thickening, Hardening (solid soap), Mold release | Liquid soap base, High solubility cleaning | Oil phase raw material |
| Cost | Medium (Cost-effective) | Lower | Higher | Fluctuates with market |
| Applicable Scenario | General industrial, Flotation, Lubrication | Solid products, Thickeners | High-end liquid cleaners | Formulations needing self-neutralization |
Selection Conclusion:
If the goal is a liquid system and a balance between cost and solubility is desired, Sodium Oleate is usually one of the options.
If the goal is solid molding, thickening, or requiring a harder soap base structure, Sodium Stearate is usually more suitable.
If there are higher requirements for low-temperature fluidity, transparency, or cold water solubility, Potassium Oleate can be prioritized for evaluation, but cost and formulation window need to be assessed simultaneously.
Part 6: Supply Chain Perspective—Packaging, Storage, and Transportation
6.1 Packaging Specifications
6.2 Golden Rules of Storage
6.3 Transportation Safety
6.1 Packaging Specifications
To adapt to factories of different scales, we provide flexible packaging solutions:
Standard Packaging: 20kg or 25kg multi-layer kraft paper bags (lined with PE moisture-proof bags). This is the most general specification, convenient for manual handling and feeding.
Large Packaging: 500kg or 1000kg Super Sacks (ton bags). Suitable for large concentrators or chemical plants with automated feeding, reducing manual bag opening and waste.
Custom Packaging: Fiber Drum. Suitable for long-distance sea export orders with extremely high requirements for compression resistance and moisture protection, but volume utilization is slightly lower and freight costs are slightly higher.
6.2 Golden Rules of Storage
Sodium Oleate can be managed as general chemicals in storage and transportation in most cases, but it should still be subject to SDS and local regulations; meanwhile, it is sensitive to humidity and temperature. Storage according to the following points is recommended:
Moisture Sensitivity: Warehouse relative humidity is recommended to be controlled below 60%. Once damp, caking or even hardening may occur, leading to poor discharge or requiring extra crushing/screening, thereby affecting feeding efficiency and metering stability.
Heat and Oxygen Sensitivity: Long-term exposure to high temperature or direct sunlight may cause oxidation of the double bond structure, leading to yellowing color and heavier odor (rancid smell). It is recommended to follow the “First In First Out (FIFO)” principle.
Suggested Shelf Life: Under unopened standard storage conditions, our recommended best use period is 12-24 months from the production date (specifics depend on storage conditions; it can still be used after the period if re-testing passes).
6.3 Transportation Safety
HS Code: Commonly classified as HS 2916.15 (Oleic, linoleic or linolenic acids, their salts and esters), subject to final customs ruling.
Transportation Regulation Level: In many product transportation classifications, it may not be managed as dangerous goods, but it should still be judged by SDS, UN/IMDG/IATA and local regulations.
GHS/Occupational Health and Environment Level: Risks like irritation/dust hazard/aquatic environment hazard may still exist, execution according to SDS is required.
Part 7: Frequently Asked Questions (FAQ)
A: We can provide both Plant-based (e.g., Olive/Palm source) and Animal-based (Tallow-based) specifications. If you have Halal or Kosher certification needs, please specify in the inquiry, we usually recommend the plant-based version.
A: Sodium Oleate is more commonly used in the aqueous phase; it usually has certain solubility in alcohol solvents like ethanol (often requires heating or ratio optimization, subject to small-scale tests). Solubility in non-polar solvents like hydrocarbons is usually low; if necessary, dispersion or compatibility can be improved through co-solvents/compound systems.
A: Due to different origins and seasons of raw materials (natural oils), Sodium Oleate from natural sources will have slight color fluctuations (from milky white to yellowish). As long as the COA/re-test shows color is within specifications, and key indicators like Iodine Value, Free Acid/Alkali are normal, it will not cause significant impact on core application performance in most cases; if used for high transparency or high stability systems, comparative small-scale tests are recommended first.
A: For customers exporting to the EU, we fully understand the importance of REACH regulations. Please contact the sales team to query the registration status for that tonnage level.
A: We support providing small samples for laboratory testing (sample specifications and shipping cycle subject to actual stock and communication confirmation), usually only requiring the customer to bear the courier fee. Regular specification samples are usually sent within 24-48 hours.
A: To support R&D and pilot tests, we support ordering from small packages; MOQ depends on specific specifications and inventory. We believe every big customer starts from a small test.
A: Mainly affected by the bulk futures price fluctuations of upstream oil raw materials (such as palm oil, tallow), as well as liquid alkali prices and environmental governance costs. Our quotations usually have validity limitations.
A: Absolutely. We have extensive experience in OEM and neutral packaging. We can hide factory information and paste your labels according to your requirements to protect your commercial channels.
A: It is usually alkaline. pH varies with batch free alkali/effective content and test concentration; please refer to COA/actual measurement.
A: It is generally not recommended for neutral or acidic systems. When pH drops to a certain range (commonly in the weak alkali to neutral range, specifically depending on concentration and water quality), Sodium Oleate may be acidified to generate oleic acid and trigger turbidity/precipitation, leading to significant decline in emulsification, cleaning, or dispersion performance. It is recommended to use it in systems with sufficient alkalinity reserve and verify the stable window through small-scale tests.
A: Direct mixing is usually not recommended. Anionic surfactants (Sodium Oleate) and cationic surfactants easily undergo ion pair/charge neutralization when compounded, resulting in turbidity, flocculation, or decrease in effective components. If compounding is indeed required, verify through ratio, addition sequence, and stabilizer system under controlled conditions.
A: Regular products do not add them. If you have special flow/dispersion requirements, we can add trace anti-caking agents (such as silica) during the production process, please propose when customizing.
A: In concrete waterproofing applications, we precisely utilize its characteristic of “fearing hard water”—letting it react with calcium ions precipitated from cement to generate insoluble hydrophobic calcium soap to block pores. This is a typical case of “utilizing a limitation”.
A: Although we use thickened packaging and pallets, violent transportation happens occasionally. If damage is found, please take photos immediately and send them to the after-sales team. We will arrange replacement or compensation as soon as possible and assist in claiming from logistics.
A: The simplest way: tell us your application industry, the competing product model you are currently using (or send a little sample to us). Our technical center will conduct benchmarking analysis and recommend the most matching (or even more cost-effective) alternative model.
Part 8: How to Start Cooperation?
After reading this long article, we believe you have “expert-level” understanding of the application and procurement of Sodium Oleate. Whether you are in the R&D selection stage, finding backup suppliers, or urgently need to solve existing quality problems, we are ready to provide support.
Why choose us?
Not just selling goods: We understand chemistry, and we understand processes even more. The advice we provide is based on real application scenarios.
Data Transparency: Support batch sample retention and traceability, COA matches incoming materials; if the customer raises quality objections within the agreed objection period, we can cooperate with re-testing and cause analysis to provide handling conclusions and corrective measures.
Stable Delivery: Maintain safety stock to ensure stable supply to old customers even during raw material fluctuation cycles.
Our Laboratory
Our Factory
Professional service
