DOWSIL 739 Black Plastic Adhesive – 300 mL Cartridge for Flexible Bonding

DOWSIL 739 is a one-component, black silicone-based adhesive and sealant designed for durable, flexible bonding of plastic, rubber, glass, and metal substrates in aerospace, automotive, and electronics applications. Its flexible cured film maintains adhesion under vibration, thermal cycling, and mechanical stress that would crack or delaminate rigid adhesive bonds, making it ideal for attaching flexible plastic covers, gaskets, and trim components in aircraft interiors and avionics enclosures.

The black color of DOWSIL 739 provides excellent aesthetic compatibility with black plastic, rubber, and electronics components, making it the preferred choice where the adhesive joint must match the surrounding component color. The cartridge format enables controlled, precise bead application using standard cartridge guns for consistent bond and seal line quality.

As a moisture-cure silicone, DOWSIL 739 cures at room temperature upon exposure to atmospheric moisture, without requiring heat or mixing of additional components. The one-component system simplifies application and eliminates the mix ratio management required by two-component adhesives.

Technical Information

DOWSIL 739 is based on a polydimethylsiloxane (PDMS) silicone polymer that crosslinks at room temperature through reaction with atmospheric moisture, forming a tough, flexible elastomeric network. The cured silicone maintains its properties across a wide service temperature range, from below-zero cold soak to elevated temperatures encountered in electronics enclosures and engine-adjacent areas.

The black pigment in DOWSIL 739 is stable and UV-resistant, maintaining color integrity on aircraft exterior and interior surfaces exposed to sunlight and weathering. The pigment system does not affect the mechanical properties or adhesion performance of the silicone formulation.

DOWSIL 739 provides good adhesion to most plastic and rubber substrates without a separate primer in most applications, simplifying the bonding process. For demanding adhesion requirements on difficult substrates such as polyolefins or fluoropolymers, a compatible DOWSIL primer may be recommended — consult the Dow technical data sheet for specific substrate and primer guidance.

Why Choose DOWSIL 739?

• ✅ One-Component System — No mixing, simple application
• ✅ Flexible Bond Film — Accommodates vibration and thermal movement
• ✅ Black Color — Matches black plastic, rubber, and electronics components
• ✅ Moisture Cure — Room temperature cure without heat equipment
• ✅ Wide Temperature Range — From cold soak to elevated service temperatures

Applications

DOWSIL 739 is used for aircraft interior plastic panel bonding, avionics enclosure sealing, rubber gasket attachment, wire harness securing, and general electronics and aerospace maintenance bonding where a flexible black silicone adhesive is required.

Frequently Asked Questions

Q: What is DOWSIL 739 used for?
A: DOWSIL 739 is used for bonding and sealing plastic, rubber, glass, and metal components in aerospace, automotive, and electronics applications. Its flexible cure makes it ideal for applications subject to vibration and thermal cycling.

Q: What is the MPN for DOWSIL 739 300mL?
A: MPN is 3151158.

Q: Is DOWSIL 739 a one-component product?
A: Yes. DOWSIL 739 is a one-component moisture-cure silicone adhesive/sealant that cures at room temperature by reacting with atmospheric moisture — no mixing is required.

Q: What color is DOWSIL 739?
A: DOWSIL 739 is black, providing aesthetic compatibility with black plastic, rubber, and electronics components.

Q: Does DOWSIL 739 require a primer?
A: In most applications, DOWSIL 739 adheres without a separate primer. For difficult substrates such as polyolefins, consult the Dow TDS for primer recommendations.