Silyl-Terminated Polyether STP / MS Polymer Tank Selection

Storing Silyl-Terminated Polyether (STP)? Start Here

Silyl-Terminated Polyether, often known as STP or MS Polymer, is a versatile moisture-cure sealant used in construction, automotive, and industrial applications. It's a non-isocyanate, HAP-free alternative to traditional polyurethane prepolymers. When storing STP, it's crucial to prevent moisture exposure to avoid in-tank curing and viscosity changes. This polymer is typically delivered in poly IBCs or stainless tanks and requires dry atmospheric storage with desiccant breathers or nitrogen blankets for long-term stability.

Can you store it in a poly tank?

Yes, you can store STP in polyethylene tanks, specifically HDPE or XLPE. These materials are standard for STP storage, provided you use a desiccant breather or nitrogen blanket to control moisture exposure. Poly tanks are favored for their chemical inertness and UV protection, especially in outdoor settings.

Moisture Control is Key

STP is highly moisture-reactive. Exposure to moisture can cause the polymer to cure inside the tank, leading to increased viscosity and skin formation. To prevent this, ensure your storage setup includes a desiccant breather or nitrogen blanket to maintain a dry atmosphere.

The safety that actually matters

• Use a desiccant breather or nitrogen blanket to prevent moisture exposure.
• Store in HDPE or XLPE tanks for chemical inertness and UV protection.
• Ensure proper ventilation and temperature control to maintain product stability.

Common questions

Can STP be stored in stainless steel tanks?

Yes, stainless steel tanks are suitable and offer excellent moisture control.

What happens if moisture gets into the tank?

Moisture exposure can cause the polymer to cure, increasing viscosity and forming a skin.

Are there specific gaskets recommended for STP storage?

EPDM and Viton gaskets are standard, with Viton preferred for premium applications.