Desmodur® W

Desmodur W diisocyanate must be stored in tightly sealed containers. Precautions must be taken to avoid contamination by moisture and air. Processability of this material can be adversely affected by contamination. Water or moisture in the air reacts with the product to generate pressure. If partially filled containers are stored, it is advisable to blanket the liquid surface with dry nitrogen before sealing.
If Desmodur W diisocyanate is stored for prolonged periods at or below a temperature of 77°F, crystallization and settling of the isomer may occur. Storage in a cold warehouse can cause crystals to form. These crystals can settle to the bottom of the container. If the crystals do form, they can be melted easily with moderate heat. It is suggested that a container the size of a drum be warmed for 16–24 hours at 104–122°F (40–50°C.) When the crystals are melted, the container should be agitated by rolling or stirring, until the contents are homogenous. Since heated Desmodur W diisocyanate (104-122°F) will generate vapors more rapidly than product at 77°F, be sure to follow the precautions listed on the MSDS in the section entitled “Personal Protection” whenever you open a heated container of Desmodur W diisocyanate.
Should it become necessary to transfer Desmodur W diisocyanate from the original containers, new containers should be of plain, clean steel, or steel lined with a suitable coating (i.e., DuPont’s Dulux 1840¬045). If Desmodur W diisocyanate is transferred to glass, use acid-washed amber or Pyrex glass. Bottle caps should be aluminum foil lined for the best moisture seal. Bung plugs used for larger containers should contain a polyethylene seal.