Polyurethane can be manufactured either in a single-component or in a two-component system. In both cases, any water still present may react with the isocyanate forming carbon dioxide gas and leading to the formation of bubbles in the final compound.
PURMOL® is a hydrophilic molecular sieve powder. It is used to remove moisture from polyurethane polymer systems in order to prevent the formation of carbon dioxide. PURMOL® products remove moisture without negatively impacting shelf-life, viscosity etc.
Other types of molecular sieve powder are used as additives for selective adsorption in defined polymer systems, e.g.
Coatings Sealants Caulks Adhesives Pigment and solvent drying Insulating glass (rubber profiles)