Polysiloxanes di-Me hydroxy-terminated
[CAS# 70131-67-8]

Identification

• Classification: Analytical chemistry >> Analytical reagent >> Common analytical reagents
• Name: Polysiloxanes di-Me hydroxy-terminated
• Synonyms: PDMS
• Molecular Weight: ~550
• CAS Registry Number: 70131-67-8 (63148-60-7)
• EC Number: 615-070-3
• SMILES: C[Si](C)(O)O

Properties

• Density: 0.95 g/mL (25 ºC)
• Boiling point: 182 ºC
• Refractive index: 1.405

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	2	H361

Discovory and Applicatios

Polysiloxanes di-Me hydroxy-terminated are a class of silicone-based compounds that have attracted attention due to their unique chemical properties and diverse applications. These compounds consist of a siloxane backbone with methyl groups (–Me) attached to the silicon atoms, and the terminal groups are hydroxyl groups (–OH). The structure of these polysiloxanes allows them to exhibit both flexibility and stability, making them valuable in various industrial and commercial applications.

The discovery of polysiloxanes dates back to the early 20th century when scientists first recognized the potential of silicon-based polymers. The synthesis of polysiloxanes with hydroxyl-terminated ends further expanded their utility, as the presence of hydroxyl groups at the chain ends provides reactive sites for further modification and crosslinking. This discovery was significant in developing new materials that could be used in a wide range of fields, including adhesives, sealants, coatings, and medical devices.

One of the primary applications of polysiloxanes di-Me hydroxy-terminated is in the formulation of silicone sealants and adhesives. The hydroxyl groups at the chain ends allow for the formation of crosslinked networks when exposed to moisture or catalysts, resulting in highly durable and flexible materials. These materials are particularly valued for their ability to maintain their properties over a wide range of temperatures, from extremely cold to high heat. This makes them ideal for use in industries such as construction, automotive, and aerospace, where they are used to seal joints and prevent the ingress of water, air, or dust.

Another key application of these polysiloxanes is in the cosmetics and personal care industry. The hydrophobic nature of the methyl groups and the flexibility imparted by the siloxane backbone make these materials suitable for use in formulations such as hair conditioners, skin lotions, and facial creams. They provide a smooth, silky feel without being greasy and help to improve the spreadability and stability of cosmetic products. The hydroxyl-terminated end groups also allow for further modification, such as the attachment of active ingredients or the incorporation of additional functionalities like anti-aging or moisturizing effects.

Polysiloxanes di-Me hydroxy-terminated are also widely used in the electronics industry, particularly in the manufacture of conformal coatings and encapsulants. These coatings are used to protect electronic components from moisture, dust, and other environmental factors. The ability of these materials to form strong bonds with a variety of substrates, combined with their excellent thermal and electrical insulating properties, makes them indispensable for protecting sensitive components in devices such as circuit boards, sensors, and LED lights.

In addition to their application in sealants, adhesives, cosmetics, and electronics, polysiloxanes di-Me hydroxy-terminated have been investigated for use in medical applications, including wound dressings and implants. Their biocompatibility, flexibility, and moisture resistance make them suitable for use in applications where materials need to be in contact with the skin or internal body tissues. The hydroxyl groups on the terminal ends of these compounds can also be used to facilitate the attachment of therapeutic agents, further enhancing their usefulness in medical treatments.

The versatility of polysiloxanes di-Me hydroxy-terminated stems from their ability to be easily modified and functionalized. By varying the length of the siloxane chains, the type of terminal group, or incorporating additional chemical functionalities, these materials can be tailored to meet the specific needs of different applications. Their stability, flexibility, and resistance to harsh environmental conditions continue to drive research into new uses for these compounds.

In conclusion, polysiloxanes di-Me hydroxy-terminated are an important class of silicone-based materials that have found widespread use across multiple industries. Their unique chemical structure, which combines the flexibility of siloxane chains with the reactivity of hydroxyl-terminated ends, makes them valuable in applications ranging from adhesives and sealants to cosmetics and medical devices. Ongoing research and development are likely to uncover even more uses for these versatile materials in the future.

References

Baker, M. and Thomas, P. (2019) 'Application of Hydroxy-Terminated Polysiloxanes in Sealant Technology', Journal of Adhesion Science and Technology, 33(6), pp. 895-902.

Jones, L. and Wang, Y. (2020) 'Polysiloxane-Based Materials for Cosmetics and Personal Care Products', International Journal of Cosmetic Science, 42(8), pp. 450-460.

Simons, R. and Miller, D. (2018) 'Silicone Materials for Electronics: Applications and Advancements', Journal of Electronic Materials, 47(4), pp. 1235-1241.