Description

(Mercaptopropyl)Methylsiloxane - Dimethylsiloxane Copolymers are a class of organosilicon compounds featuring both dimethylsiloxane units and mercaptopropylmethylsiloxane units, offering a unique combination of silicone backbone flexibility and reactive thiol functionality. This dual nature makes them a critical intermediate for modifying polymer properties and creating crosslinked networks. These copolymers are essential for manufacturers requiring precise control over material characteristics such as adhesion, hydrophobicity, and mechanical strength. They are primarily utilized in the production of advanced sealants, adhesives, and coatings across the electronics, automotive, and construction industries.

Application

• Adhesion Promoters: Key component in primers and coupling agents to improve the bond between organic polymers and inorganic surfaces like glass, metals, and minerals.
• Crosslinking Agents: Used in UV-curable and peroxide-curable silicone rubber formulations, where the thiol groups participate in radical or addition reactions to form durable elastomers.
• Surface Modification: Imparts hydrophobic and release properties to surfaces in textile, paper, and mold release applications.
• Sealants & Adhesives: Enhances the flexibility, adhesion, and durability of high-performance silicone-based sealants and adhesives for construction and automotive assembly.
• Polymer Modification: Acts as a chain transfer agent or modifier in the synthesis of specialty polymers to introduce silicone segments and tailor properties like weatherability and low-temperature flexibility.
• Optical & Electronic Encapsulants: Used in formulations for potting and protecting sensitive electronic components and LED devices due to their stable silicone backbone and curing versatility.

Basic Information

Product Name	(Mercaptopropyl)Methylsiloxane - Dimethylsiloxane Copolymers
CAS No.	102783-03-9
Molecular Formula	(C6H14OSi)x·(C2H6OSi)y
Molecular Weight	Varies by copolymer ratio (Contact for details)
Synonyms	Mercaptopropylmethylsiloxane-Dimethylsiloxane Copolymer; Poly[dimethylsiloxane-co-(3-mercaptopropyl)methylsiloxane]; 3-Mercaptopropylmethylsiloxane-dimethylsiloxane copolymer; Thiol-functional polysiloxane; SH-PDMS; Mercapto-modified silicone oil; Mercaptopropyl silicone fluid; Reactive silicone copolymer
EINECS	Contact for details

Quality Control

Our (Mercaptopropyl)Methylsiloxane - Dimethylsiloxane Copolymers are produced under a stringent quality management system. Each batch is characterized for critical parameters including mercaptan (SH) content, viscosity, molecular weight distribution, and purity to ensure consistent performance in your formulations. Certificates of Analysis (COA) documenting these specifications are available upon request. We adhere to industry best practices to support your compliance needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Due to its easily oxidized nature, it is recommended to store under an inert atmosphere (e.g., nitrogen) for long-term preservation to maintain thiol functionality. Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	Colorless to pale yellow clear liquid
Identification (IR)	Complies
Viscosity (25°C)	Specified grade (e.g., 100-10,000 cSt)
Mercaptan (SH) Content	Specified grade (e.g., 0.5 - 5.0 mmol/g)
Specific Gravity (25°C)	0.95 - 1.05
Refractive Index (nD25)	1.40 - 1.45
Water Content	< 0.1%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.