Cross-linker (Part B): Cure_temperature 100-180°C

Component Specifications

Definition

Cross-linker (Part B) is a critical reactive component in two-part liquid silicone rubber (LSR) systems, typically containing platinum catalysts and inhibitors. When mixed with Part A (base polymer with vinyl groups), it initiates a hydrosilylation reaction that forms cross-links between silicone polymer chains, transforming the liquid mixture into a solid elastomer with specific mechanical, thermal, and chemical properties.

Working Principle

Works through platinum-catalyzed hydrosilylation reaction where silicon-hydride (Si-H) groups in Part B react with vinyl (Si-CH=CH2) groups in Part A. The platinum catalyst facilitates the addition of Si-H across the carbon-carbon double bond, creating covalent Si-C bonds that connect polymer chains into a three-dimensional network. Reaction rate is controlled by inhibitors that temporarily deactivate the catalyst until heat is applied.

Materials

Typically contains: Polysiloxane with silicon-hydride functional groups (30-70%), Reaction inhibitors (e.g., vinyl siloxanes, acetylene derivatives), Inert fillers (optional, for viscosity adjustment), Stabilizers (for shelf life).

Technical Parameters

Parameter	Typical range	Notes & selection driver
Cure Time	30-300 seconds
Shelf Life	6-12 months (unopened, 25°C)
Si H Content	0.1-1.5 mol/kg
Viscosity 25C	500-5000 mPa·s
Pot Life Mixed	2-48 hours
Cure Temperature	100-180°C
Mixing Ratio A B	1:1 typically (varies by formulation)
Platinum Content	50-500 ppm
Specific Gravity	0.95-1.05

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 10993, ISO 16256, DIN 53504, ASTM D5289

Parent Products

This component is used in the following industrial products

Liquid Silicone Rubber

A two-part, platinum-catalyzed silicone elastomer that cures at elevated temperatures to form durable, flexible rubber parts.

View Product Details

Engineering Analysis

Risks & Mitigation

Premature curing if contaminated
Platinum catalyst poisoning by sulfur/amine compounds
Exothermic reaction if mixed incorrectly
Shelf life degradation if stored above 25°C

FMEA Triads

Trigger: Catalyst poisoning from contaminated equipment
Failure: Incomplete curing, tacky surface
Mitigation: Implement strict cleaning protocols, use dedicated equipment, test raw materials

Trigger: Incorrect mixing ratio
Failure: Poor mechanical properties, dimensional instability
Mitigation: Automated metering systems, ratio verification sensors, regular calibration

Trigger: Moisture absorption during storage
Failure: Reduced reactivity, bubble formation
Mitigation: Sealed containers, desiccant packs, controlled humidity storage

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Mixing ratio ±1%, platinum content ±10%, viscosity ±15%

Test Method

FTIR for Si-H content, ICP-OES for platinum, rheometry for cure characteristics, ISO 16256 for biocompatibility (medical grades)

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Cross-linker (Part B)

Manufacturer profiles associated with Cross-linker (Part B).

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

Related Components

Tie Layer

Tie layer is a bonding component in multi-layer co-extruded barrier films that ensures adhesion between incompatible polymer layers.

Mold Release Coating

Specialized coating applied to molds to facilitate easy release of silicone seal rings during manufacturing.

Silicone Polymer Base

Silicone polymer base is a high-temperature resistant polymer material used as the foundational component in silicone rubber compounds for industrial applications.

Reinforcing Filler

Reinforcing filler is a material added to silicone rubber compounds to enhance mechanical properties, thermal stability, and durability in high-temperature applications.

Frequently Asked Questions

What happens if Cross-linker Part B is contaminated with moisture?

Moisture causes premature hydrolysis of Si-H groups, reducing cross-linking efficiency and potentially causing incomplete curing, bubbles, or weak spots in the final product.

Can different brands of Part B be mixed with Part A from another manufacturer?

No, cross-linkers are formulation-specific. Mixing components from different systems typically results in improper curing, poor mechanical properties, or complete failure.

How is pot life extended in LSR systems?

Through inhibitors that temporarily bind to platinum catalyst. Heat during molding releases the inhibitor, allowing the reaction to proceed at controlled rates.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Cross-linker (Part B)