MS7188 is a two-component, MS polymer, based joint sealant specially designed for long-term sealing of concrete expansion joints in demanding infrastructure applications. By mixing Component A and B at the specified ratio, the sealant cures through moisture-triggered crosslinking. The curing speed is temperature-dependent, faster at higher temperatures and slower in colder conditions, allowing flexible application in different environments.

With its ultra-low modulus, exceptionally high elongation and excellent elastic recovery, MS7188 effectively accommodates large joint movements caused by thermal expansion, contraction and structural deformation. It provides reliable adhesion to both porous and non-porous substrates, including concrete, stone, metal and masonry.

Once cured, MS7188 forms a smooth, durable surface that can be sanded and painted, ensuring both functional performance and clean appearance in large-scale civil engineering projects.

Key Features & Benefits

• Ultra-low modulus & high elongation (≥600%)
  Effectively absorbs large joint movements without cracking or debonding.
• Excellent elastic recovery (>70%)
  Fast response and minimal permanent deformation under repeated joint movement.
• Low odor & low VOC formulation
  Free from isocyanates, PVC and organic solvents for safer application.
• Outstanding UV and weather resistance
  Designed for long-term outdoor exposure with a service life exceeding 20 years.
• Low shrinkage after curing
  Maintains joint profile with no sinking or surface defects.
• Substrate-friendly stress behavior
  Applies controlled low stress to concrete during passive deformation, protecting the concrete surface.
• Paintable & sandable after curing
  Allows seamless integration with surrounding surfaces.

Typical Applications

MS7188 is engineered for long-lasting weatherproof sealing of concrete expansion joints in infrastructure and transportation projects, including:

• Airport runways and aprons
• Highways and expressways
• Bridges and elevated roads
• Tunnels and metro systems
• Other concrete pavement expansion joints

Application Notes

• Ensure bonding surfaces are clean, dry, oil-free, and dust-free before application.
• Mix Component A and Component B thoroughly within 5–10 minutes.
• Remove surface rust or oxidation from metal substrates prior to sealing.
• Always conduct pre-application testing due to variations in substrates and site conditions.
• Recommended application temperature: +15°C to +40°C.
  

In low-temperature environments, adjusting the proportion of Component B can help improve curing efficiency.

Technical Specifications

Item	Specification	Standard / Notes
Base Material	MS Polymer
Appearance	A: White paste / B: Black paste	Visual
Density	Approx. 1.4 g/cm³	23°C x 50% RH
Sag Resistance	<3.0 mm	JC/T 976-2005
Pot Life	>40 min	23°C x 50% RH
Tack-Free Time	<4 h
Elastic Recovery	>70%	JC/T 976-2005
Tensile Modulus (23°C)	≤0.3 MPa	JC/T 976-2005
Tensile Modulus (-20°C)	≤0.6 MPa
Elongation at Break	≥600%
Adhesion at 100% Extension		JC/T 976-2005
Adhesion After Water Immersion
Adhesion After Cold Stretch & Heat Compression
Mass Loss	≤5%	JC/T 976-2005
Service Temperature	-40°C to +90°C	Max. 180°C (<20 min)
UV & Weather Resistance	No yellowing or cracking after 6 weeks UV	Artificial UV aging

Test specimens cured at 23°C x 50% RH for 28 days.