MS728 is a single-component MS polymer sealant that cures at room temperature. Its curing speed depends on ambient temperature and humidity, with faster skin formation under high temperature and humidity, and slower curing under low temperature or low humidity. The final cure time is also affected by the sealant thickness.

Key Features

• Low odor, low VOC, free of isocyanates, PVC, and organic solvents, safe to use.
• UV-resistant and durable in extreme temperatures, with a service life exceeding 20 years.
• Minimal shrinkage after curing, smooth and glossy surface without depressions.
• Can be used in bridge suspension coating applications, compliant with main cable corrosion protection standards (JT/T694-2007).
• Medium modulus with high elongation and excellent rebound properties.
• Compatible with various porous and non-porous substrates, paintable and sandable.

Applications

Elastic sealing for joints on stainless steel, aluminum, coated surfaces and more.

Excellent adhesion to fluorocarbon paints, epoxy primers and phosphating primers.

Suitable for brushing, injection, caulking, surface sealing or pre-made tape and reinforced fabric wrapping.

Typical Use Cases

Bridge main cable systems: sealing cable loop joints, butt joints and saddle clamp grooves.

Metal structures, ventilation hoods, ducts, warehouses, modular buildings.

Welds, connection points, galvanized sheets, rivets, bolts and anti-corrosion sealing.

Usage Guidelines

• Surfaces must be clean, dry and free from dust and oil.
• Oily substrates are unsuitable for direct sealing.
• Rusted or corroded metal surfaces should be treated before application.
• Always test adhesion before large-scale use due to environmental and material differences.
• Recommended application temperature: 15°C – 40°C. Cold conditions may increase extrusion resistance.

Technical Specifications

Property	Specification	Test Method
Appearance	Black / White / Grey, uniform ice-cream paste	Visual
Density	~1.41 g/cm³	GB/T533
Non-volatile Content	≥97%	HB6743
Working Time	0.5-2 h	Touch Test
Skin Time	8-24 h	HB5242
Slump	≤10 mm	HB5243
Tensile Strength	≥2.5 MPa	HB5246
Elongation at Break	≥280%	GB/T528
Heat Aging (120°C for 7 days)	Tensile ≥2.0 MPa, Elongation ≥150%	HB5246/HB5247
Adhesion	Phosphate/Epoxy primer ≥4 kN/m	HB5249
Corrosion Resistance	Immersion in 3% NaCl at 60°C for 20d – no corrosion or degradation	HB5273

Packaging

• 300ml cartridge
• 570ml sausage
• 20L drum

Storage & Shelf Life:

Store in a cool, dry place at 10–25°C (max 45°C)

12-month shelf life.

Avoid extreme heat or freezing

Keep original packaging sealed