Typical Formulation Ingredients
Ingredient
Parts by weight
Polybutadiene polyol (Poly BD R45HT, Sartomer)
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Chain extender (2-ethyl-1, 3-hexanediol
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Asphalt
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Isocyanate (Isonate 143L, NCO index = 1.05)
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Resulting Properties
There are many types of polyurethanes used in the building and construction industry. A very popular type is one that is formulated with hydroxyl terminated polybutadiene and conventional isocyanates. These formulations provide excellent compatibility with modified asphalt systems. Some specific applications include penetration joints and adhesives on EPDM or asphalt roofing, adhesives and sealants for crack filling or expansion joints, and waterproof membranes and coatings (see next section). Typical formulations for polybutadiene based polyurethane sealants are shown in the table above.