Siloxanes and Silicones, di-Me, 3-aminopropyl group-terminated
[CAS# 106214-84-0]

Identification

• Classification: Chemical reagent >> Organic reagent >> Siloxane
• Name: Siloxanes and Silicones, di-Me, 3-aminopropyl group-terminated
• Synonyms: 3-[[[3-aminopropyl(dimethyl)silyl]oxy-dimethylsilyl]oxy-dimethylsilyl]propan-1-amine
• Molecular Formula: H2N(CH₂)_3Si(_CH3)_2O[_Si(_CH3)_2O]_nSi(_CH3)₂(_CH2)_3NH2
• Molecular Weight: ~2500
• CAS Registry Number: 106214-84-0
• EC Number: 600-723-7
• SMILES: C[Si](C)(CCCN)O[Si](C)(C)O[Si](C)(C)CCCN

Properties

• Density: 0.98 g/mL (25 °C) (Expl.)
• Boiling point: >200 °C (Expl.)
• Refraction index: 1.410 (Expl.)

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Risk Statements: H315-H318-H319-H335-H400-H410
• Safety Statements: P261-P264-P264+P265-P271-P273-P280-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin corrosion	Skin Corr.	1B	H314
Specific target organ toxicity - single exposure	STOT SE	3	H336
Skin corrosion	Skin Corr.	1C	H314
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411

Discovery and Applications

Siloxanes and silicones, di-Me, 3-aminopropyl group-terminated, refer to a class of organosilicon compounds that consist of polydimethylsiloxane (PDMS) chains with terminal functional groups containing 3-aminopropyl substituents. These materials are a specific subset of amino-functional silicones and have been widely developed and applied in industrial, cosmetic, and biomedical fields due to their unique combination of silicone backbone properties and reactive amino terminal groups.

The core structure of these compounds is based on repeating –Si(CH₃)₂–O– units, forming a flexible, hydrophobic, and thermally stable siloxane polymer chain. The 3-aminopropyl groups are covalently bonded to the terminal silicon atoms of the polymer, introducing reactive primary amine functionalities. The presence of these amino groups allows for further chemical modification, crosslinking, or interaction with various substrates and surfaces.

These aminopropyl-terminated silicones were developed to expand the application range of silicone materials by introducing functionalities that enhance adhesion, reactivity, and compatibility with other materials. The terminal amino groups can participate in condensation reactions, epoxy or isocyanate curing, and hydrogen bonding, making them particularly valuable in applications requiring surface treatment, coupling, or adhesion to organic and inorganic materials.

In industrial use, these functional silicones serve as intermediates or additives in the formulation of adhesives, sealants, and coatings. They improve bonding performance to substrates such as glass, metal, and plastics, which would otherwise be difficult for conventional silicones to adhere to. They are also employed in sol-gel processes, resin modification, and surface functionalization.

In cosmetics and personal care products, low molecular weight variants of these aminopropyl-terminated silicones are utilized for their conditioning properties. They can deposit onto hair or skin and form flexible films that improve softness, smoothness, and manageability. The amino functionality can enhance substantivity to keratinous surfaces, leading to longer-lasting effects in rinse-off applications like shampoos and conditioners.

In biomedical and pharmaceutical fields, research has explored their use in drug delivery systems, medical adhesives, and tissue-compatible materials. Their flexibility, low toxicity, and biocompatibility make them suitable candidates for applications that require controlled surface interactions or long-term skin contact.

These compounds are typically clear to slightly yellowish fluids, with viscosities ranging from low (several hundred centistokes) to high depending on the degree of polymerization. They exhibit excellent thermal and oxidative stability and low surface energy, while the amino terminal groups introduce hydrophilic and reactive characteristics to an otherwise inert silicone backbone.

Safety evaluations have shown that these materials are generally considered safe in formulated products when used appropriately. The reactivity of the amino groups may pose irritation risks if used at high concentrations or in uncontrolled applications. Proper formulation and end-use testing are important to ensure product performance and safety.

In summary, siloxanes and silicones, di-Me, 3-aminopropyl group-terminated, are functionalized silicone polymers with terminal primary amino groups that enhance their reactivity and surface interaction properties. Their unique combination of silicone flexibility and amine functionality enables widespread use in industrial, cosmetic, and emerging biomedical applications.

References

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