Name: Silicone-MS Hybrid Polymer SMH-30
Brand: Coatingsink
SKU: silicone-ms-hybrid-polymer-smh
Availability: InStock

Question 1

How does SMH-30 compare to standard MS polymers in cure speed?

Accepted Answer

SMH-30 incorporates siloxane backbone segments alongside the polyether blocks, which enhances moisture diffusion and accelerates silanol condensation at the terminal silane groups. Tack-free time is typically 20–40% shorter than a pure MS polymer of equivalent viscosity under the same relative humidity, without requiring elevated amine catalyst loading.

Question 2

Can SMH-30-based sealants be overcoated with waterborne topcoats?

Accepted Answer

Yes. The surface energy of the fully cured elastomer (approximately 28–32 mN/m) falls within the wetting window for most acrylic latex and alkyd facade paints. No primer is required on the cured bead under standard conditions, though adhesion testing on the specific paint system is always recommended before production.

Question 3

Which crosslinker and catalyst system pairs well with SMH-30?

Accepted Answer

Methyltrimethoxysilane (MTMS) or vinyltrimethoxysilane at 3–6 phr provides adequate crosslink density for elastic sealant grades. Titanate catalysts such as tetrabutyl titanate at 0.5–2 phr are preferred over organotin to meet current REACH restrictions and achieve a balanced open time and cure-through profile.

Color	Colorless to pale yellow
Density (25°C)	1.07 g/ml
Moisture Content	<0.05%
Viscosity (25°C)	35,000–45,000 mPa·s
Silane Content (Si-OMe)	1.8–2.2 mmol/g

Silicone-MS Hybrid Polymer SMH-30

Specifications

FAQ

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