Dibutyl Sebacate (DBS): Technical Specifications and Industrial Applications

1. Technical Overview

Dibutyl Sebacate (DBS), chemically known as bis(butyl) decanedioate ($C_{18}H_{34}O_4$), is a high-performance, bio-based plasticizer produced through the esterification of Sebacic acid with n-butanol. It is a clear, colorless, and odorless liquid. In industrial R&D, DBS is recognized for its exceptional efficiency in providing low-temperature flexibility and high compatibility with a wide array of polymers, including polyvinyl chloride (PVC), polyvinyl butyral (PVB), and various synthetic rubbers. Due to its low toxicity and superior migration resistance, it is frequently utilized in sensitive applications such as food-grade packaging, medical-grade tubing, and high-clarity films.

2. Chemical Structure & Composition

The molecular structure of DBS consists of a linear 10-carbon sebacate chain with two butyl ester groups at the termini.

• Molecular Weight: 314.46 g/mol.

• Composition: High-purity diester content (>99%).

• Functionality: The linear structure allows for efficient insertion between polymer chains, reducing intermolecular forces and increasing molecular mobility.

The 10-carbon sebacate backbone provides higher thermal stability and lower volatility compared to shorter-chain phthalate or adipate plasticizers.

3. Physical & Chemical Properties

• Appearance: Colorless, transparent liquid.

• Viscosity: 7.0 – 11.0 cSt at 25°C.

• Refractive Index: 1.439 – 1.443 at 20°C.

• Boiling Point: ~344°C at atmospheric pressure.

• Flash Point: ~180°C (Closed Cup).

• Solubility: Insoluble in water; highly soluble in alcohols, ketones, and most organic solvents.

4. Reaction Chemistry

DBS is chemically stable under normal industrial processing conditions:

1. Plasticization Mechanism: It acts as an external plasticizer, physically blending with the polymer matrix without forming chemical bonds.

2. Solvating Power: It exhibits high solvating power for PVC at elevated temperatures, facilitating fast fusion during extrusion or calendaring.

3. Resistance to Hydrolysis: The ester bonds are stable in most neutral environments, though they can be hydrolyzed by strong acids or bases at high temperatures.

5. When to Use vs. When NOT to Use

Use Dibutyl Sebacate when:

• Manufacturing food-contact materials (films, gaskets, bottle cap liners).

• Formulating specialized PVC compounds that must remain flexible at sub-zero temperatures (e.g., cold storage curtains).

• Producing high-clarity PVB interlayers for safety glass.

Do NOT use Dibutyl Sebacate when:

• The application involves continuous exposure to high temperatures (above 100°C) in an open environment, where its moderate volatility might lead to eventual hardening.

• A low-cost, general-purpose plasticizer is sufficient for a non-sensitive, indoor application (where phthalates might be more economical).

6. Compatibility Profile

DBS is highly compatible with:

• Polymers: PVC, PVB, Nitrocellulose, Ethyl Cellulose, and Polystyrene.

• Synthetic Rubbers: Nitrile rubber (NBR) and Chloroprene rubber (CR).

• Solvents: Acts as an excellent solvent for various resins and cellulose derivatives.

7. Manufacturing Process (Product Focus)

The production of DBS at Nova Industries involves:

1. Esterification: High-purity Sebacic acid is reacted with n-butanol in the presence of an acid catalyst.

2. Neutralization: The excess acid is neutralized with a mild alkali wash.

3. Stripping: Unreacted butanol is removed under vacuum.

4. Distillation: The final product is vacuum distilled to ensure a colorless appearance and to remove trace impurities, resulting in a product with a purity level of 99.5% or higher.

8. Technical Specifications Table

Parameter	Specification (High Purity)
Appearance	Colorless, Transparent Liquid
Purity (by GC)	99.5% Min
Color (APHA)	20 Max
Acid Value (mg KOH/g)	0.05 Max
Moisture Content	0.10% Max
Specific Gravity (at 20°C)	0.935 – 0.940
Refractive Index (at 20°C)	1.439 – 1.443

9. Quality Grade Analysis

Nova Industries focuses on the Acid Value and Color (APHA). A low acid value is critical for preventng the degradation of sensitive polymers and maintaining the electrical insulation properties of the compound. Our ultra-low APHA color ensures that the plasticizer does not impart any yellow tint to clear films or safety glass interlayers.

10. Impact of Impurities

• Residual Alcohol (Butanol): Can lead to odor issues and lower the flash point, posing a safety risk during high-temperature processing.

• Moisture: Interferes with the fusion process in PVC and can cause haziness in transparent films.

11. Industry-Wise Application 1: Food & Medical Packaging

DBS is widely used in food-grade PVC films and medical-grade gaskets because of its low toxicity and compliance with FDA regulations. It provides the necessary flexibility without the safety concerns associated with certain phthalates.

12. Industry-Wise Application 2: Safety Glass (PVB Interlayers)

In the manufacture of laminated safety glass, DBS is used as a plasticizer for the PVB interlayer. It ensures the film remains flexible and maintains its energy-absorbing properties over a wide temperature range.

13. Industry-Wise Application 3: Low-Temperature Lubricants

Used as a component in synthetic lubricants and hydraulic fluids that must operate in arctic conditions. Its low pour point and stable viscosity make it an ideal choice for high-altitude or polar environments.

14. Industry-Wise Application 4: Nitrocellulose Coatings

In high-end furniture finishes and nail polishes, DBS acts as a non-yellowing plasticizer that provides a smooth, high-gloss finish with excellent crack resistance.

15. Formulation Guide

• Dosing: In PVC compounds, typical loading is 10–40 phr (parts per hundred resin), depending on the desired hardness.

• Incorporation: DBS should be pre-blended with the resin in a high-speed mixer before feeding into the extruder or calendar.

16. Sustainability Data

Dibutyl Sebacate is a bio-based plasticizer. By utilizing Sebacic acid derived from castor oil, it offers a sustainable alternative to petroleum-derived plasticizers, helping manufacturers meet green labeling requirements and reduce their carbon footprint.

17. Packaging & Logistics (Technical)

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

• Bulk: 1000kg IBC Tanks or ISO Tanks.

• Logistics: Non-hazardous for transport. Protect from moisture and extreme heat.

18. Storage Science

DBS is chemically stable but should be stored in a cool, dry area away from direct sunlight. To prevent oxidation and moisture absorption, drums should be kept tightly sealed. For bulk storage, 316-grade stainless steel tanks are recommended.

19. Troubleshooting Guide

• Problem: Migration or “bleeding” on the surface. Solution: Check the compatibility with the polymer or ensure the dosage is not exceeding the saturation limit.

• Problem: Fogging or haziness in clear films. Solution: Check for moisture contamination in the DBS or the resin.

20. Regulatory Compliance

Our DBS is REACH Compliant, TSCA listed, and meets the requirements of the FDA for use in food-contact materials. It is also compliant with RoHS and various international safety standards.

21. Safety (SDS Summary)

• Handling: Wear protective gloves and eye protection.

• Toxicity: Low oral and dermal toxicity; however, avoid prolonged exposure.

• Fire: High flash point; in case of fire, use CO2, foam, or dry chemical extinguishers.

22. Sample Validation Process

Check the Purity (by GC) and Acid Value. For film applications, a laboratory-scale “Clarity and Migration Test” is recommended to ensure performance meets specific application standards.

23. Commercial Efficiency

Using Nova Industries’ high-purity DBS ensures consistent processing and fewer production rejects. The low odor and colorless nature of the product reduce the need for corrective additives, lowering the overall formulation cost.

24. Technical FAQs

1. Is DBS safe for food-contact applications? Yes, it is widely recognized for its safety and is used in many FDA-compliant applications.

2. How does it compare to DOP? DBS offers much better low-temperature flexibility and is bio-based, whereas DOP is petroleum-derived and has regulatory restrictions in many regions.

3. What is the shelf life? 12–24 months when stored in original, unopened packaging.

25. Contact CTA

For Technical Data Sheets (TDS), safety protocols, or to request a sample of our High-Purity DBS, please contact our export department: export@novaind.in

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