2,2′-Dimorpholinodiethylether
DMDEE is the catalyst behind many one-component moisture-curing polyurethanes: it stays quiet in the can and wakes up when the film meets humidity.
DMDEE is two morpholine rings joined through a diethyl ether bridge (molecular weight 244.33 g/mol). It is a pale yellow liquid with low volatility and a high boiling point of about 309 °C.
DMDEE is used in one-component moisture-cure polyurethane prepolymers: coatings, sealants, adhesives, waterproofing membranes and spray foam. It promotes the reaction of isocyanate with water, which drives moisture cure, while giving good storage stability in isocyanate-terminated prepolymers.
DMDEE can irritate the eyes and skin. Use eye protection and gloves and ensure ventilation, especially when it is heated or sprayed. Store tightly closed and dry, and follow the SDS for the specific grade.
It speeds up the isocyanate–water reaction that cures the film, while having only limited effect on stability of the sealed prepolymer, so shelf life stays acceptable.
Yes. Moisture cure releases CO₂, and a fast catalyst in thick films or high humidity can produce gas faster than it can escape. Thinner coats and controlled dosage help.
Typically fractions of a percent of the formulation. Follow the formulation or supplier guidance, because too much shortens shelf life and increases bubbling.