Typical Formulation Ingredients
Phase
Ingredient
Parts by weight
A (Polyol Component):
Polybutadiene resin (Poly bd R45HTLO, Cray Valley)
A (Polyol Component):
Asphalt AA4909 (407 pen.)
A (Polyol Component):
White mineral oil (Renoil, Renkert Oil)
A (Polyol Component):
Dibutyltin dilaurate catalyst (T-12, Dabco)
B (Isocyanate Component):
Polymeric diphenylmethane diisocyanate (Mondur MRS 2, Convestro)
Typical Properties
There appears to be no significant difference in performance of adhesives based upon either Isonate 143L or Mondur MRS 2
Low temperature flexibility (due to low Tg of Poly bd)
High temperature resistance (due to crosslinking)
Good chemical resistance (dependent on asphalt concentration)
Good adhesion to construction materials
Compatibility with high loading of fillers.
Resulting Properties
The formulations above are for general purpose two component asphalt filled polyurethane adhesives based on polybutadiene polyol. Using polybutadiene polyol will provide much better hydrolytic stability than other conventional polyols (e.g., polyester or polyether).
Often additives are not required to provide flexibility or toughness as in the case of epoxy formulations. Polyurethanes have the capability of providing these properties through manipulation of the resulting molecule by proper choice of isocyanate and polyol. However, additives are used mainly to stabilize the adhesive relative to moisture, oxidation, UV, etc.
(Source: Cray Valley)