Methyl Ricinoleate (MR): Technical Properties and Industrial Versatility

1. Technical Overview

Methyl Ricinoleate (MR) is a methyl ester derived from the transesterification of refined castor oil.² Chemically known as methyl 12-hydroxy-9-octadecenoate (³$C_{19}H_{36}O_3$), it is a clear, low-viscosity liquid.⁴ Unlike the parent castor oil, Methyl Ricinoleate possesses a significantly lower molecular weight and reduced viscosity, which enhances its penetration and plasticizing efficiency. In industrial R&D, MR is valued for its trifunctionality—the ester group, the double bond, and the secondary hydroxyl group. This unique structure makes it a superior bio-based intermediate for specialized surfactants, cutting fluids, and high-performance plasticizers for various polymers.

2. Chemical Structure & Composition

Methyl Ricinoleate is the primary methyl ester found in the esterified profile of castor oil.

• Methyl Ricinoleate Content: Typically 85–90%.

• Secondary Components: Small percentages of Methyl Oleate, Methyl Linoleate, and Methyl Stearate.

• Molecular Architecture: A long 18-carbon chain with a hydroxyl group at C12 and a methoxy group at the carboxyl terminus.

The presence of the hydroxyl group provides higher polarity than standard fatty acid methyl esters (FAME), allowing MR to act as a powerful solvent and coupling agent in complex chemical systems.

3. Physical & Chemical Properties

• Appearance: Pale yellow to transparent, clear liquid.⁵

• Viscosity: ~0.3 to 0.5 stokes at 25°C (Significantly lower than castor oil).

• Solubility: Fully soluble in most organic solvents including alcohols, ketones, and hydrocarbons. Insoluble in water but easily emulsifiable.

• Refractive Index: 1.468 – 1.472 at 25°C.

• Pour Point: Remains liquid at low temperatures (approx. -10°C), offering better handling characteristics than the parent oil.

4. Reaction Chemistry

The versatility of MR stems from its three reactive sites:

1. The Methoxy Group: Allows for rapid transesterification with other alcohols to create specialized esters.

2. The Hydroxyl Group: Acts as a site for ethoxylation to produce non-ionic surfactants or for reaction with isocyanates to create polyurethane intermediates.

3. The Double Bond: Facilitates hydrogenation to produce Methyl 12-HSA or sulfonation for industrial wetting agents.

5. When to Use vs. When NOT to Use

Use Methyl Ricinoleate when:

• You require a bio-based, biodegradable plasticizer for nitrocellulose, ethyl cellulose, or vinyl resins.

• Formulating metalworking fluids that need superior lubricity and polar adhesion to metal surfaces.

• Synthesizing high-purity surfactants where low viscosity of the feedstock is required for process efficiency.

Do NOT use Methyl Ricinoleate when:

• The application requires high-temperature stability in an open system (above 150°C), as esters may undergo thermal degradation.

• A high-viscosity binder is required (use Castor Oil or DCO instead).

• The application is strictly aqueous and cannot accommodate the use of emulsifiers.

6. Compatibility Profile

MR exhibits excellent compatibility with:

• Polymers: PVC, PVB, Nitrocellulose, and various synthetic rubbers.

• Oils: Blends seamlessly with mineral oils, synthetic esters, and other vegetable oils.

• Resins: Highly compatible with alkyd and phenolic resins.⁶

7. Manufacturing Process (Product Focus)

Nova Industries produces MR through a high-efficiency transesterification process:

1. Reaction: Refined castor oil is reacted with anhydrous methanol in the presence of a specialized alkaline catalyst.

2. Glycerin Separation: The byproduct (glycerin) is separated using high-speed centrifuges.

3. Washing & Purification: The methyl ester phase is washed to remove residual catalyst and unreacted methanol.

4. Vacuum Distillation: The product is distilled under a high vacuum to remove heavy ends, ensuring a light color and high purity level.

8. Technical Specifications Table

Parameter	Specification (Methyl Ricinoleate)
Appearance	Pale Yellow to Colorless Clear Liquid
Acid Value (mg KOH/g)	2.0 Max
Iodine Value (Wijs)	80 – 90
Saponification Value	175 – 185
Hydroxyl Value	150 – 160
Moisture & Volatiles	0.20% Max
Color (Gardner)	2.0 Max
Specific Gravity (at 30°C)	0.915 – 0.925

9. Quality Grade Analysis

Nova Industries focuses on the Low Acid Value and Moisture Control. A high acid value in MR can lead to the degradation of sensitive polymers when used as a plasticizer. Our vacuum distillation ensures that unreacted fatty acids are removed, providing a chemically neutral product that enhances the shelf life of the final formulation.

10. Impact of Impurities

• Residual Methanol: Lowers the flash point and can cause odor issues in cosmetic or indoor coating applications.

• Unreacted Triglycerides: Increase the viscosity and can lead to “bleeding” or migration when MR is used as a plasticizer.

11. Industry-Wise Application 1: Plastics & Polymers

MR is a primary bio-plasticizer for nitrocellulose and ethyl cellulose.⁷ It provides excellent flexibility, low-temperature impact resistance, and high gloss to finished plastic products. Its polar nature ensures it stays within the polymer matrix better than non-polar plasticizers.

12. Industry-Wise Application 2: Metalworking Fluids

In the lubricant industry, MR is used in cutting and grinding oils.⁸ The hydroxyl group provides a strong affinity for metallic surfaces, creating a stable lubricating film that reduces friction and heat generation during high-speed machining.

13. Industry-Wise Application 3: Surfactants & Emulsifiers

Used as a feedstock for producing alkanolamides and ethoxylated surfactants. These derivatives are widely used in the textile, leather, and crop protection industries due to their high biodegradability.

14. Industry-Wise Application 4: Cosmetics & Personal Care

Acts as a non-greasy emollient and solvent in skin care products.⁹ It is often used as a carrier for pigments in decorative cosmetics, ensuring a smooth and even application.

15. Formulation Guide

• Incorporation: MR can be added directly to the solvent phase or the polymer melt.

• Emulsification: For water-based systems, use a non-ionic emulsifier with an HLB of 10–12 to create a stable emulsion.

16. Sustainability Data

Methyl Ricinoleate is 100% bio-based and renewable. It is classified as “Readily Biodegradable,” making it an environmentally responsible choice for applications where the product may eventually enter the ecosystem, such as in total-loss lubricants.

17. Packaging & Logistics (Technical)

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

• Bulk: 1000kg IBC Tanks or ISO Tanks.

• Storage Stability: MR is stable for transport but should be protected from extreme heat to prevent oxidation of the double bond.

18. Storage Science

MR should be stored in a cool, dry area.¹⁰ Because it contains an unsaturated double bond, it is sensitive to atmospheric oxygen. For long-term storage, 316-grade stainless steel tanks with nitrogen blanketing are recommended to preserve the color and iodine value.

19. Troubleshooting Guide

• Problem: Darkening of the product during storage. Solution: Ensure the container is air-tight; check for iron contamination from mild steel storage.

• Problem: Migration or “oiling out” in plastics. Solution: This may indicate the presence of unreacted triglycerides; verify the viscosity of the MR batch.

20. Regulatory Compliance

Our Methyl Ricinoleate is REACH Compliant, meeting the stringent chemical safety standards for the European market. It is also listed on major global chemical inventories (TSCA, DSL, IECSC).

21. Safety (SDS Summary)

• Handling: Use standard protective equipment. MR is not classified as hazardous.

• Flash Point: High (>170°C), providing a wide safety margin in industrial processing.¹¹

• Environment: Non-toxic to aquatic life; however, large spills should be contained using absorbent materials.

22. Sample Validation Process

For laboratory approval, we recommend testing the Viscosity and Hydroxyl Value. For plasticizer applications, a compatibility test with the specific resin (checking for clarity and migration) is the most reliable validation method.

23. Commercial Efficiency

Direct procurement from Nova Industries ensures a product with a high methyl ester content and minimal residual methanol. This high purity leads to more efficient downstream chemical reactions and higher-quality final products, reducing overall manufacturing costs.

24. Technical FAQs

1. How is MR different from Castor Oil? MR has a much lower viscosity and molecular weight, making it a better solvent and a more efficient plasticizer than the parent oil.¹²

2. Is Methyl Ricinoleate biodegradable? Yes, it is derived from vegetable oil and is inherently biodegradable.¹³

3. Can it be used as a fuel additive? Yes, it provides excellent lubricity to diesel fuels, protecting fuel pumps and injectors from wear.¹⁴

25. Contact CTA

For Technical Data Sheets (TDS), customized purity levels, or bulk export pricing, please contact our technical sales department at: export@novaind.in