ABDP-1201

Technical Data Sheet: Antmee® Vinylmethyl-Dimethyl Polysiloxane Copolymers

Product Name: Antmee® Vinylmethyl-Dimethyl Polysiloxane Copolymer
Chemical Description: Vinylmethylsiloxane-Dimethylsiloxane Copolymer / Pendant Vinyl-Functional Silicone Fluid
CAS Number: 68083-18-1 (Vinyl Terminated) / 67762-94-1 (Trimethylsiloxy Terminated) 
Molecular Structure: Linear polysiloxane backbone with dimethyl and vinylmethyl repeating units; terminal groups may be vinyl or trimethylsiloxy depending on grade

1. Product Overview

Antmee® Vinylmethyl-Dimethyl Polysiloxane Copolymers are clear, colorless linear silicone fluids characterized by reactive vinyl functional groups distributed along the polymer backbone as pendant vinylmethylsiloxane units. Unlike standard vinyl-terminated polydimethylsiloxanes which contain only two terminal vinyl groups per chain, these copolymers feature multiple vinyl sites per molecule, enabling higher crosslink density and more robust network formation in addition-cure (hydrosilylation) silicone systems .

This series serves as a versatile component in two-part platinum-catalyzed silicone formulations, functioning either as a reactive crosslinker or as a high-performance base polymer for specialty elastomers. The multiple pendant vinyl groups provide enhanced reactivity and allow formulators to precisely engineer the mechanical properties—including hardness, tear strength, and modulus—of the final cured silicone product .

2. Typical Physical & Chemical Properties

The following specifications represent the general physical properties of the Antmee® Vinylmethyl-Dimethyl Polysiloxane Copolymer series. Actual values vary depending on the specific vinyl content, molecular weight, and terminal group configuration.

• Appearance: Clear, colorless transparent liquid (Visual) 

• Active Content: 100 % 

• Density (at 25°C): Approx. 0.97 – 0.98 g/mL 

• Refractive Index (at 25°C): Approx. 1.403 – 1.420 

• Flash Point: > 200 °C 

• Boiling Point: > 205 °C 

• Pour Point: < -40 °C 

• Solubility: Insoluble in water; soluble in common aromatic and aliphatic organic solvents; miscible with diethyl ether 

• Odor: Essentially odorless 

Disclaimer: Typical values are representative of average production lots and should not be interpreted as guaranteed batch-specific specifications. Minor variations are expected due to normal manufacturing tolerances.

3. Standard Specifications by Product Grade

The Antmee® Vinylmethyl-Dimethyl Polysiloxane Copolymer series is available in various viscosity grades and vinyl content specifications. Please refer to the specific Antmee® product code for detailed Certificate of Analysis (CoA) data, including precise vinyl equivalent weight and molecular weight distribution.

Antmee® VMC-200 to VMC-500 Series
These are low to medium viscosity copolymers with moderate pendant vinyl content. They provide excellent reactivity while maintaining good flow and handling characteristics. This series is particularly well-suited as reactive diluents and crosslinker components in liquid silicone rubber (LSR) formulations, where they help control system viscosity while contributing to the final crosslink network. Typical vinylmethylsiloxane content ranges from 0.8% to 2.0%.

Antmee® VMC-800 to VMC-1200 Series
Medium to high viscosity grades offering a balance between pendant vinyl concentration and polymer chain length. These copolymers are the industry workhorse for general-purpose addition-cure elastomers, providing enhanced tear strength and elongation compared to purely linear vinyl-terminated systems. They serve as effective modifiers for improving the toughness and abrasion resistance of silicone rubber compounds .

Antmee® VMC-HV Series (High Vinyl Content)
High vinyl content copolymers featuring 7.0-8.0 mol% vinylmethylsiloxane repeating units . These grades provide maximum crosslink density in hydrosilylation cure systems, resulting in cured elastomers with higher hardness, improved chemical resistance, and lower compression set. They are recommended for applications requiring robust mechanical integrity under demanding service conditions, including automotive gaskets, high-performance sealants, and electronic encapsulation compounds.

4. Primary Applications

• Addition-Cure Silicone Elastomers: Serves as a crosslinker or co-base polymer in two-part platinum-catalyzed RTV and LSR systems. The pendant vinyl groups react with hydride-functional crosslinkers to form a tightly crosslinked, durable elastomeric network with excellent thermal stability .

• High-Temperature Vulcanizing (HTV) Rubber: Functions as an additive or base gum modifier in peroxide-cured HTV silicone compounds. Enhances the mechanical strength, hardness, and overall physical integrity of the final elastomer .

• Polymer Modification: Used as an additive to modify the physical properties of organic polymers, including thermoplastics and thermosets. Imparts improved low-temperature flexibility, weatherability, scratch resistance, and internal lubrication .

• Mold Release and Processing Aids: Provides excellent release properties and internal lubrication in plastic processing and rubber molding applications. Reduces coefficient of friction and improves surface smoothness of finished articles .

• Electrical and Electronic Insulation: Formulated into potting compounds, encapsulants, and conformal coatings for electronic components. The cured silicone provides superior dielectric properties and protection against moisture, dust, and environmental degradation .

• Sealants and Adhesives: Contributes to the formulation of durable, weather-resistant sealants for construction, automotive, and industrial assembly applications requiring long-term adhesion and flexibility under temperature extremes .

5. Packaging and Storage Information

• Packaging Options: Available in 20 kg pails, 50 kg HDPE drums, or 200 kg steel drums depending on viscosity and volume requirements. Custom packaging available upon request.

• Shelf Life: 36 months (3 years) from the date of manufacture when stored in the original, unopened container under recommended conditions . Product may be retested and used after the expiration date if specifications are met.

• Storage Conditions: Store in a cool, dry, and well-ventilated area away from direct sunlight, moisture, and sources of heat or ignition. Keep containers tightly sealed when not in use to prevent contamination. Recommended storage temperature range: 5°C to 35°C. Product does not require protection from freezing; however, viscosity will increase at lower temperatures. Allow material to equilibrate to room temperature before use .