Typical Formulation Ingredients
Phase
Ingredient
Parts by weight
Prepolymer Component
200 g/mol 12% EO-capped PO/EO triblock polyol
Prepolymer component
200 g/mol PTMEG
Prepolymer
Surfactant, 1000 g/mol methoxy ethylene glycol
Prepolymer
Surfactant, 1000 g/mol polyethylene glycol
Prepolymer
Sodium dodecyl benzene sulfonate
Chain extender
1,2-Propane diamine
Typical Properties
Molecular weight of prepolymer, g/mol
Molecular weight of PU polymer
Adhesion, nylon to PET, lb/in
Adhesion polyethylene to Al foil, lb/in
Resulting Properties
Polyurethane adhesives also give the formulator more freedom in “engineering” the modulus and elongation required of the adhesive film to meet specific applications. New continuous PU dispersion technology has led to the creation of novel PUDs based upon polyether polyols and methylene diphenyl diisocyanate (MDI). These PU dispersions are solvent free, high solids (50-60 wt), and have submicron sized particles and excellent stability. The PUDs from this process have been found useful for designing PSAs with properties ranging from removable to high shear strength.
The source of Waterborne Polyurethane Adhesive is Cranley, P., et. al., “Polyurethane Dispersion Based Pressure Sensitive Adhesives”, Dow Chemical Co., Freeport, TX.