Dehydrated Castor Oil Fatty Acid (DCOFA): Technical Specifications and Chemical Versatility

1. Technical Overview

Dehydrated Castor Oil Fatty Acid (DCOFA) is a liquid polyunsaturated fatty acid produced through the hydrolysis of Dehydrated Castor Oil (DCO).¹ It is distinguished by its high content of conjugated linoleic acid isomers ($9,11$-octadecadienoic acid). Unlike standard fatty acids, DCOFA offers exceptional drying properties and a high degree of cross-linking. In industrial chemistry, DCOFA is the premium choice for synthesizing high-solids alkyd resins, epoxy esters, and specialized surfactants where rapid oxidative drying, film hardness, and non-yellowing characteristics are mandatory requirements.

2. Chemical Structure & Composition

The molecular profile of DCOFA is defined by the removal of the hydroxyl group from the original ricinoleic chain to create a system of conjugated and non-conjugated double bonds.²

• Conjugated Linoleic Acid ($9,11$-isomer): Typically 25%–30%, providing the primary drying speed.

• Non-Conjugated Linoleic Acid ($9,12$-isomer): Provides film flexibility and adhesion.

• Saturated Fatty Acids: Minimal presence to ensure the product remains liquid at low temperatures.

The presence of these double bonds allows for rapid polymerization via a free-radical mechanism when exposed to oxygen, creating a dense, durable molecular network.

3. Physical & Chemical Properties

DCOFA is a clear, light-colored liquid with high reactivity:³

• Appearance: Pale yellow to transparent liquid.⁴

• Viscosity: Low viscosity at room temperature, facilitating easy pumping and mixing.

• Titer: Low solidification point, ensuring the material remains liquid even in cooler warehouse conditions.

• Acid Value: High (190–200 mg KOH/g), facilitating rapid and complete esterification reactions.⁵

• Iodine Value: 135–155, indicating high unsaturation and drying potential.

4. Reaction Chemistry

DCOFA is a highly functional building block for synthetic chemists:

1. Esterification: Reacts with polyols (pentaerythritol, glycerin) to form high-performance alkyd binders.

2. Epoxidation: Can be reacted with epichlorohydrin to create epoxy esters for automotive primers.⁶

3. Maleinization: Reacts with maleic anhydride to produce water-reducible resins.

4. Diels-Alder Reaction: The conjugated system allows for easy modification with various monomers to enhance resin hardness.

5. When to Use vs. When NOT to Use

Use DCOFA when:

• Manufacturing high-quality white industrial enamels that must resist yellowing.

• Producing air-drying or stoving finishes requiring high gloss and chemical resistance.

• Formulating high-performance printing ink vehicles.

Do NOT use DCOFA when:

• The application requires a non-drying fatty acid (use Ricinoleic Acid or Stearic Acid instead).

• Cost is the only factor and yellowing is acceptable (standard Linseed fatty acids are more economical).

6. Compatibility Profile

DCOFA exhibits excellent compatibility with:

• Resins: Acrylics, phenolics, and various amino resins.

• Solvents: Fully soluble in aromatic hydrocarbons, esters, and ketones.

• Cross-linkers: Highly compatible with melamine and isocyanate curing agents.

7. Manufacturing Process (Product Focus)

The production of DCOFA at Nova Industries involves:

1. Dehydration: First, refined castor oil is dehydrated under vacuum and high temperature to create DCO.

2. Hydrolysis (Splitting): The DCO is then subjected to high-pressure steam splitting to separate the fatty acids from the glycerin.

3. Distillation: The resulting fatty acid is vacuum distilled to concentrate the ⁷$9,11$ and ⁸$9,12$ isomers and remove any residual impurities or heavy fractions.⁹

4. Stabilization: Trace amounts of antioxidants may be added to ensure the high iodine value remains stable during transit.

8. Technical Specifications Table

Parameter	Specification (DCOFA)
Appearance	Pale Yellow Liquid
Color (Gardner)	3.0 Max
Acid Value (mg KOH/g)	190 – 200
Iodine Value (Wijs)	135 – 155
Saponification Value	195 – 205
Moisture & Volatiles	0.5% Max
Conjugated Diene Content	25% – 30%

9. Quality Grade Analysis

Nova Industries monitors the Conjugated Diene Content as the ultimate indicator of quality. A higher conjugation percentage directly translates to faster drying times for the customer. Inferior DCOFA often has a conjugation level below 20%, leading to “soft” films that are prone to picking up dust during the drying phase.

10. Impact of Impurities

• Residual Hydroxyls: Indicate incomplete dehydration; they will slow down the drying speed and reduce the water resistance of the final coating.

• High Unsaponifiables: Can lead to a reduction in film gloss and integrity over time.

11. Industry-Wise Application 1: Industrial Coatings

DCOFA is the gold standard for high-performance industrial paints. It provides a unique combination of rapid drying, excellent adhesion to metal, and superior resistance to oils and grease.

12. Industry-Wise Application 2: Printing Inks

In the ink industry, DCOFA is used to produce quick-drying varnishes for offset and lithographic inks. Its high iodine value ensures the ink “sets” quickly on the substrate without smudging.

13. Industry-Wise Application 3: Automotive Primers

Epoxy esters made with DCOFA are widely used in automotive undercoats and industrial primers due to their exceptional corrosion resistance and flexibility.

14. Industry-Wise Application 4: Specialty Surfactants

Used as a raw material for biodegradable surfactants and emulsifiers that require a polyunsaturated hydrophobic tail.

15. Formulation Guide

• Esterification: During resin cooking, maintain a nitrogen blanket to preserve the light color of the DCOFA.

• Drier Selection: Use a combination of Cobalt and Zirconium driers to achieve an optimal balance of surface and through-drying.

16. Sustainability Data

DCOFA is a 100% bio-based fatty acid. It offers a sustainable alternative to petroleum-based monomers in resin synthesis and contributes significantly to the “Green Carbon” content of industrial coatings.

17. Packaging & Logistics (Technical)

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

• Bulk: ISO Tanks or 1000kg IBC Tanks.

• Logistics: DCOFA is a non-hazardous liquid, but should be handled with care to avoid spills due to its high iodine value (reactivity with air).

18. Storage Science

DCOFA is a highly reactive, unsaturated fatty acid.¹⁰ It must be stored in a cool, dry place away from direct sunlight. To prevent “skinning” or polymerization inside the drum, containers should be kept tightly sealed. For bulk storage, 316-grade stainless steel tanks with nitrogen blanketing are essential.

19. Troubleshooting Guide

• Problem: Resin batch turns dark. Solution: Check for trace iron contamination or insufficient nitrogen flow during the cooking process.

• Problem: Poor drying in high humidity. Solution: Increase the dosage of the auxiliary drier (Zirconium) or check the conjugation level of the DCOFA batch.

20. Regulatory Compliance

Our DCOFA is REACH Compliant, ensuring it meets the environmental and safety standards required for the European and Global markets.

21. Safety (SDS Summary)

• Handling: Wear protective gloves and eye protection.

• Spontaneous Combustion: Rags or filter aids soaked with DCOFA can catch fire spontaneously. Always store these in water-filled metal containers.

• Fire: Use dry chemical, CO2, or foam extinguishers.

22. Sample Validation Process

For laboratory trials, we recommend a Gas Chromatography (GC) Analysis to verify the fatty acid distribution and conjugation percentage. A laboratory-scale resin cook is the best way to validate performance in your specific formulation.

23. Commercial Efficiency

Direct sourcing of DCOFA from Nova Industries ensures a high-purity product with consistent conjugation. This consistency allows resin manufacturers to standardize their cooking cycles, leading to higher factory efficiency and fewer batch corrections.

24. Technical FAQs

1. What is the difference between DCO and DCOFA? DCO is the triglyceride (oil), while DCOFA is the free fatty acid. DCOFA is used when the formulation requires a direct reaction with other polyols or epoxy groups.

2. Is DCOFA non-yellowing? Yes, compared to Linseed or Soybean fatty acids, DCOFA is significantly better at resisting yellowing in white enamels.

3. Does DCOFA have a strong odor? It has a characteristic fatty odor, but our distillation process ensures it is neutral enough for high-end industrial applications.

25. Contact CTA

For Technical Data Sheets (TDS) or specific conjugation requirements, please contact our technical sales team at: export@novaind.in