MS Polymer Construction Sealant/Adhesive

ALSEAL AS-4001 is a single-component, moisture-curing MS polymer sealant and adhesive designed for movement joints and general construction sealing applications. The product is formulated to provide elastic performance, substrate adhesion, and durability under typical building service conditions.

The cured sealant forms an elastic rubber with ±50% joint movement capability (ASTM C719), suitable for dynamic joints subject to expansion and contraction. It demonstrates stable curing characteristics due to its solvent-free and isocyanate-free formulation, minimising risks of shrinkage, bubbling, or blistering during cure. The absence of silicone oil reduces the potential for surface staining on adjacent materials.

AS-4001 exhibits adhesion to a wide range of common construction substrates, including concrete, masonry, anodised aluminium, coated metals, GRC panels, timber, UPVC, polystyrene, stainless steel, and composite materials. In many applications, primerless adhesion is achievable; however, for porous or damp substrates (e.g. concrete), the use of AS-602 primer is recommended to ensure consistent bond performance.

The sealant is compatible with most common industrial paint systems (subject to project-specific verification), making it suitable for applications where overcoating is required.

Key Technical Properties

• Movement capability: ±50% (ASTM C719)
• Density: 1.54 g/mL
• Ultimate tensile at break: 1.1 N/mm² (ASTM D412)
• Elongation: 600% (ASTM D412)
• Shore A hardness: 33 (ASTM C661)
• Elastic recovery: >70% (ISO 7389)
• Slump (ASTM D2202): <1 mm
• VOC content: <10 g/L (USEPA Method 24)
• Cure rate: approx. 3 mm / 24 hrs @ 23°C, 50% RH
• Service temperature: -20°C to +90°C
• Tack free time: 20-60 min

Standards & Compliance

• ASTM C920, Type S, Grade NS, Class 50, Use NT & M
• ISO 11600, Class 25 LM
• GECA certified (Good Environmental Choice Australia)
• LEED v4.1 EQ compliant (low-emitting materials criteria)
• VOC: compliant with SCAQMD Rule 1168 (USEPA Method 24)
• Tested in accordance with FDA 21 CFR 175.300 (resin and polymer coatings)

Summary for Specification

ALSEAL AS-4001 is a high-movement, MS polymer-based construction sealant/adhesive suitable for façade, structural joint, and perimeter sealing applications where elastic recovery, adhesion to multiple substrates, and paintability are required. Selection should be based on project-specific performance requirements, joint design, and compatibility with adjacent materials.