Castor Oil Fatty Acid (COFA): Technical Specifications and Industrial Applications

1. Technical Overview

Castor Oil Fatty Acid (COFA) is the mixture of fatty acids obtained from the hydrolysis (splitting) of refined castor oil. Unlike the parent triglyceride, COFA exists as a free fatty acid, which significantly increases its chemical reactivity. It is characterized by its exceptionally high content of Ricinoleic acid (approx. 90%), which provides a unique trifunctional structure: a carboxyl group, a double bond, and a secondary hydroxyl group. In industrial R&D, COFA is a vital liquid intermediate used for the synthesis of high-performance alkyd resins, transparent soaps, and specialized surfactants where the presence of the glycerin backbone is not required.

2. Chemical Structure & Composition

COFA is primarily composed of 12-hydroxy-9-octadecenoic acid.

• Ricinoleic Acid: ~88–90%.

• Linoleic & Oleic Acid: ~7–9%.

• Saturated Acids (Stearic/Palmitic): ~1–2%.

• Functional Profile: The secondary hydroxyl group on the C12 position remains the defining feature, providing polarity and sites for cross-linking.

The high concentration of a single hydroxy-fatty acid makes COFA far more predictable in chemical reactors compared to mixed fatty acids from other vegetable sources.

3. Physical & Chemical Properties

• Appearance: Yellow to amber viscous liquid at room temperature.

• Viscosity: Higher than standard fatty acids due to intermolecular hydrogen bonding.

• Acid Value: 175 – 185 mg KOH/g.

• Iodine Value: 82 – 92.

• Saponification Value: 180 – 190.

• Titer (Solidification Point): 3°C to 6°C, ensuring it remains liquid in most industrial climates.

4. Reaction Chemistry

COFA’s trifunctionality allows for complex chemical engineering:

1. Esterification: Reacts with polyols (like pentaerythritol) to create flexible, non-yellowing alkyd resins.

2. Saponification: Reacts with lithium or sodium hydroxides to form high-solubility soaps and grease thickeners.

3. Ethoxylation: The hydroxyl group can be reacted with ethylene oxide to create non-ionic emulsifiers.

4. Condensation: Can be self-polymerized to form estolides, used as high-performance lubricant additives.

5. When to Use vs. When NOT to Use

Use COFA when:

• Manufacturing high-solids alkyd resins where glycerin must be avoided to control viscosity.

• Formulating liquid soaps or textile auxiliaries requiring high wetting power.

• Producing metallic ricinoleates for the rubber or plastics industry.

Do NOT use COFA when:

• A solid, saturated wax is required (use 12-HSA instead).

• The application requires a non-polar fatty acid (standard Stearic or Oleic acid would be more compatible with mineral oils).

• High-temperature oxidative stability in an open system is the only requirement (unsaturated bonds may oxidize).

6. Compatibility Profile

COFA exhibits excellent compatibility with:

• Solvents: Completely soluble in alcohols, ketones, and aromatic hydrocarbons.

• Resins: Highly compatible with epoxy, phenolic, and amino resins.

• Polymers: Acts as a secondary plasticizer for nitrocellulose and some rubbers.

7. Manufacturing Process (Product Focus)

The production of COFA at Nova Industries involves:

1. Splitting: Refined castor oil is subjected to high-pressure steam hydrolysis (Colgate-Emery process) to break the triglyceride into fatty acids and glycerin.

2. Separation: The fatty acid layer is separated from the “sweet water” (glycerin phase).

3. Washing: The crude acid is washed to remove trace mineral acids and residual glycerin.

4. Vacuum Drying: De-moisturization under vacuum ensures a moisture content below 0.5%, preventing premature oxidation.

8. Technical Specifications Table

Parameter	Specification (Standard Grade)
Appearance	Yellowish Amber Viscous Liquid
Acid Value (mg KOH/g)	175 – 185
Iodine Value (Wijs)	82 – 92
Saponification Value	180 – 190
Hydroxyl Value	150 – 165
Moisture & Volatiles	0.5% Max
Color (Gardner)	6.0 Max

9. Quality Grade Analysis

Nova Industries monitors the Degree of Splitting via the Acid Value. A low acid value indicates residual monoglycerides, which can cause cloudiness and inconsistent reaction times in resin manufacturing. Our high-conversion process ensures a nearly pure fatty acid profile with minimal unsaponifiables.

10. Impact of Impurities

• Residual Glycerin: Can cause smoke and unwanted charring during high-temperature resin cooking.

• Moisture: Promotes the development of dark oxidation products and can interfere with the stoichiometry of polyurethane reactions.

11. Industry-Wise Application 1: Alkyd Resins & Coatings

COFA is a premium choice for manufacturing “medium-oil” and “long-oil” alkyd resins. It provides the final coating with exceptional flexibility, adhesion, and “non-yellowing” characteristics, making it ideal for high-quality decorative paints and industrial finishes.

12. Industry-Wise Application 2: Textile & Leather Auxiliaries

Used to produce sulfonated and ethoxylated derivatives that act as powerful wetting agents, emulsifiers, and leveling agents in fabric dyeing and leather fat-liquoring.

13. Industry-Wise Application 3: Metallic Soaps

COFA is reacted with zinc, calcium, or aluminum to produce metallic ricinoleates. These are used as lubricants and stabilizers in the rubber and PVC industries.

14. Industry-Wise Application 4: Personal Care

Used in the manufacture of transparent bar soaps and specialized shampoos. The ricinoleic content provides a unique creamy lather and acts as a mild antimicrobial agent.

15. Formulation Guide

• Resin Cooking: COFA reacts faster than castor oil because it doesn’t require the initial heat to break the triglyceride bond. Monitor the exothermic peak carefully.

• Soap Making: Account for the high acid value when calculating the caustic soda (NaOH) requirements to ensure a neutral finished product.

16. Sustainability Data

COFA is a 100% bio-based, renewable fatty acid. It is fully biodegradable and offers a lower carbon footprint compared to synthetic fatty acids derived from petroleum paraffin.

17. Packaging & Logistics (Technical)

• Standard: 190kg/200kg HDPE or MS Drums.

• Bulk: ISO Tanks or 1000kg IBC Tanks.

• Logistics: Non-hazardous. However, because it is a liquid fatty acid, it can be corrosive to mild steel over long periods; epoxy-lined or HDPE containers are preferred.

18. Storage Science

Should be stored in a cool, dry place. COFA is sensitive to air exposure; once a drum is opened, it should be used promptly or blanketed with nitrogen. For bulk storage, 316-grade stainless steel tanks are mandatory to prevent iron contamination, which would turn the acid dark red.

19. Troubleshooting Guide

• Problem: Darkening of the resin batch. Solution: Check for iron contamination in the COFA or ensure the nitrogen flow in the reactor is sufficient.

• Problem: Unexpected viscosity increase in storage. Solution: This may indicate oxidative polymerization; ensure the drums are kept airtight.

20. Regulatory Compliance

Our COFA is REACH Compliant, meets the requirements for various international safety inventories (TSCA, DSL, IECSC), and is produced under strict quality control.

21. Safety (SDS Summary)

• Handling: Use protective gloves and goggles; it is a mild skin and eye irritant.

• Fire: Flash point >200°C. Use CO2, dry chemical, or foam extinguishers.

• Environment: Biodegradable, but large spills should be contained to prevent oxygen depletion in water bodies.

22. Sample Validation Process

Test for Acid Value and Hydroxyl Value. For resin manufacturers, a “Color Stability Test” (heating a sample to 200°C for 1 hour) is recommended to ensure the acid doesn’t darken excessively during production.

23. Commercial Efficiency

Direct procurement from Nova Industries ensures a high-purity product with a consistent ricinoleic profile. This consistency allows manufacturers to standardize their production cycles and reduce the need for batch-to-batch formulation adjustments.

24. Technical FAQs

1. Is COFA different from Ricinoleic Acid? COFA is the total mixture of acids from castor oil (approx. 90% RA), whereas “Ricinoleic Acid” usually refers to the more highly purified or distilled grade.

2. Can I use it to make biodiesel? Yes, it is a high-quality feedstock, though its high viscosity requires specialized transesterification parameters.

3. Does it stay liquid in winter? Yes, with a titer of ~5°C, it remains a liquid in most indoor industrial environments.

25. Contact CTA

For Technical Data Sheets (TDS), customized fatty acid profiles, or to request a sample, please contact our technical sales team: export@novaind.in

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