Distearyl thiodipropionate
[CAS# 693-36-7]

Identification

• Classification: Analytical chemistry >> Standard >> Pharmacopoeia standards and magazine standards
• Name: Distearyl thiodipropionate
• Synonyms: Dioctadecyl 3,3'-thiodipropionate
• Molecular Formula: C₄₂H₈₂O₄S
• Molecular Weight: 683.17
• CAS Registry Number: 693-36-7
• EC Number: 211-750-5
• SMILES: CCCCCCCCCCCCCCCCCCOC(=O)CCSCCC(=O)OCCCCCCCCCCCCCCCCCC

Properties

• Density: 0.9±0.1 g/cm³, Calc.^*
• Melting point: 65-67 °C
• Index of Refraction: 1.473, Calc.^*
• Boiling Point: 704.8±45.0 °C (760 mmHg), Calc.^*
• Flash Point: 323.7±16.7 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07;GHS08 Danger
• Risk Statements: H302-H312-H332-H340-H412
• Safety Statements: P273-P280

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Specific target organ toxicity - repeated exposure	STOT RE	2	H373

Discovery and Applications

Distearyl thiodipropionate (DSTDP) is a chemical compound classified as a thiodipropionate ester, known for its significant role as an antioxidant and stabilizer in various industrial applications. The discovery of distearyl thiodipropionate dates back to the 1950s, when researchers began exploring the properties of thiodipropionic acid and its derivatives for their potential to inhibit oxidative degradation in polymers and other materials. DSTDP is synthesized through the esterification of thiodipropionic acid with stearyl alcohol, resulting in a compound that combines two stearyl groups with a thiodipropionate backbone.

The primary application of distearyl thiodipropionate is in the plastics industry, where it is utilized as an antioxidant to enhance the thermal stability and longevity of polymeric materials. By effectively scavenging free radicals and preventing oxidative chain reactions, DSTDP helps to preserve the mechanical and physical properties of polymers during processing and end-use. This is particularly crucial for materials exposed to heat and light, as oxidative degradation can lead to discoloration, brittleness, and loss of structural integrity.

In addition to its role in plastics, distearyl thiodipropionate is also employed in the formulation of lubricants and greases. Its antioxidant properties contribute to the stability and performance of these products, reducing wear and extending the service life of mechanical components. DSTDP is often incorporated into metalworking fluids, where it helps to maintain the performance of cutting tools and improve surface finishes.

Furthermore, distearyl thiodipropionate finds application in the automotive industry, particularly in the formulation of engine oils and fuels. By minimizing oxidative degradation, it helps to protect engine components and improve fuel efficiency. The compound is also utilized in the production of rubber and elastomers, where it enhances the durability and resistance to aging of the final products.

Despite its beneficial properties, the use of distearyl thiodipropionate raises some environmental and health concerns, particularly related to the potential for bioaccumulation and toxicity associated with organophosphate compounds. As a result, regulatory agencies have established guidelines to ensure that its application in various industries is safe and environmentally responsible.

In conclusion, distearyl thiodipropionate is a valuable chemical compound with diverse applications in plastics, lubricants, and automotive products. Its antioxidant properties contribute to the stability and longevity of materials, making it an essential component in various industrial formulations while highlighting the importance of monitoring its safety and environmental impact.

References

2010. Final Safety Assessment of Thiodipropionic Acid and Its Dialkyl Esters as Used in Cosmetics. International Journal of Toxicology, 29(4).
DOI: 10.1177/1091581810373150

2020. QSARs and Read-Across for Thiochemicals: A Case Study of Using Alternative Information for REACH Registrations. Methods in Pharmacology and Toxicology.
DOI: 10.1007/978-1-0716-0150-1_22