Octamethylcyclotetrasiloxane
[CAS# 556-67-2]

Identification

• Classification: Organic raw materials >> Organosilicon compound
• Name: Octamethylcyclotetrasiloxane
• Molecular Formula: C₈H₂₄O₄Si₄
• Molecular Weight: 296.62
• CAS Registry Number: 556-67-2
• EC Number: 209-136-7
• SMILES: C[Si]1(O[Si](O[Si](O[Si](O1)(C)C)(C)C)(C)C)C

Properties

• Density: 0.956
• Melting point: 17-18 °C
• Boiling point: 175-176 °C
• Refractive index: 1.395-1.397
• Flash point: 56 °C
• Water solubility: INSOLUBLE

Safety Data

• Hazard Symbols: GHS08;GHS09 Warning
• Risk Statements: H361f-H410
• Safety Statements: P203-P210-P233-P240-P241-P242-P243-P273-P280-P303+P361+P353-P318-P370+P378-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Reproductive toxicity	Repr.	2	H361
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Flammable liquids	Flam. Liq.	3	H226
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Reproductive toxicity	Repr.	2	H361f
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	4	H312
Reproductive toxicity	Repr.	2	H361f

• Transport Information: UN 1993

Discovery and Applications

Octamethylcyclotetrasiloxane (OMCTS), also known as D4, is a member of the siloxane family characterized by its ring structure and silicon chemistry. OMCTS was discovered in the mid-20th century during the development of silicon-based polymers and materials. Its synthesis involves the polymerization of siloxane monomers to form a ring structure in which eight methyl groups are attached to silicon atoms.

The molecular formula of Octamethylcyclotetrasiloxane is C8H24O4Si4. It is a colorless, odorless, low-viscosity liquid. OMCTS is characterized by low surface tension and high thermal stability. The compound is unreactive under normal conditions and is suitable for a variety of applications. Its chemical structure gives it unique properties, including flexibility and resistance to degradation.

In cosmetics, OMCTS can be used as a conditioning agent and emollient. It improves the texture and spreadability of products such as lotions, shampoos, and conditioners. Its low viscosity and smooth spreading properties make it a preferred ingredient in high-quality cosmetic formulations. It can be used in hair and skin care products because it provides a silky, smooth feel and enhances product stability. OMCTS helps reduce the greasy feel of formulations while maintaining their effectiveness.

OMCTS is used as a precursor to synthesize silicone polymers and resins. These polymers are valued for their heat resistance, water resistance, and flexibility. The compound helps produce high-performance materials used in sealants, adhesives, and coatings. OMCTS is incorporated into the formulation of lubricants and greases for its low volatility and high lubricity properties. It improves the performance and stability of these products under extreme conditions.

In the electronics industry, OMCTS is used to manufacture electronic components and coatings. It provides dielectric properties and enhances the performance of insulating materials used in electronic devices. The compound is used in protective coatings for its water and corrosion resistance properties. It helps extend the life of the coated surface by providing a durable barrier against environmental factors.

While OMCTS is generally considered safe, it is recommended to use gloves and goggles to avoid direct contact. Ensure that areas where the compound is used or stored are well ventilated. Store OMCTS in a cool, dry place away from sources of ignition and incompatible materials. Proper storage helps maintain the stability and effectiveness of the compound.

The compound is not readily biodegradable, but its impact on the environment can be minimized by following proper disposal methods. Avoiding releases into water sources helps reduce potential ecological risks. Compliance with environmental regulations ensures responsible use and disposal of OMCTS, minimizing any adverse effects on the environment.

References

2024. Research progress on eco-friendly rubber release agents. Colloid and Polymer Science, 302(11).
DOI: 10.1007/s00396-024-05339-7

2024. Preparation of Super Slippery Surface of Polyimide Composite Microspheres. Polymer Science, Series B, 66(6).
DOI: 10.1134/s1560090424601146

2024. Estimating Recovery in the Evaporation Chemical Space. Biomedical Materials & Devices, 2(3).
DOI: 10.1007/s44174-024-00163-7