Molecular Sieve Powder Used as Moisture Absorber in Polyurethane Systems

Purmol® molecular sieve is a synthetic zeolite produced in powder and paste form. It provides an optimal solution for removing water molecules from the environment. Purmol® is used in two-component polyurethane systems in the production of sealants, cast resins, coatings and adhesives. Polyurethane is formed from the reaction of a polyol with isocyanate. Since this is an addition reaction, no by-product is formed.

The presence of water causes dimerization of the isocyanate and carbon dioxide gas is released.

Carbon dioxide gas release is intentional in polyurethane foam production but is an undesired occurrence in many other polyurethane applications. This results from the formation of gas bubbles. If residual moisture in fillers and pigments in the formulation appears as water molecules, we recommend adding Purmol® to the polyol before adding the isocyanate to the polyol component. Our recommended dosage is between 2.5% and 5%. The viscosity of the formulation increases sharply; premature curing occurs or uncontrollable foaming develops. To ensure complete water adsorption, the polyol should be mixed for at least two hours before adding to the isocyanate. Additionally, Purmol® removes water molecules from the substrate surface and becomes coated. This ensures the formation of a bubble-free smooth homogeneous polyurethane layer.

Purmol® Types

Purmol 3ST Purmol 4ST

Purmol® Moisture-Absorbing Advantages

High moisture retention capacity Low pH value

Purmol® Application Areas

Polyurethane Floor Coatings, Polyurethane Adhesives, Polyurethane Paints and Varnishes, Polyurethane Fill Casting, Polyurethane Elastomers Polyurethane Sealants, Adhesives, Sealants, Coatings, Furniture Mold Casting, Polyurethane Cast Compounds, Two-Component Polyurethane Yacht Varnish, Two-Component Polyurethane Yacht Enamel, Two-Component Semi-Gloss Polyurethane Yacht Primer, Two-Component Gloss Polyurethane Top Coat Paint, Two-Component Polyurethane Primer Yacht Paint.

Metal Powder Coatings

Cosmetic Self-Heating Face Mask, Glass Insulation, Spacer Insulated Glass. If pipe systems are protected particularly against abrasion or corrosive chemicals, polyurethane coating is the ideal solution for such cases. The service life of the pipe system is very important. To maintain long-term polymer quality and optimal performance, Purmol® should be added to the formulation.

High-Quality Pipe Coating

In high-voltage insulation products, the homogeneity of the insulating body is extremely important. Defects in cast compounds cause short circuits. The high-quality requirements of this application are reliably met through Purmol® use.

Cast Compounds for High-Voltage Electrical Insulation

Mold materials, such as the sole of sports shoes, must be clean, flawless and soft. It is important that products are manufactured with solid pressure. Both requirements apply to the use of polyurethanes in appropriate formulations. Therefore, Purmol® provides very good performance.

In Mold Materials

Durable floor coatings are characterized by resistance to abrasion, flat and soft surface and high stability combination. Polyurethane coatings are frequently used in such areas. The polymer is generally applied as a liquid layer and then forms a flat and durable floor coating. Purmol® prevents irregularities from water molecules and gas bubbles formed in the coating from water presence.  

Floor Coating

Glass insulation is the main customer of molecular sieves. Molecular sieve beads are filled into cavities in the aluminum section and shaped between glass panes and serve as an intermediate layer for insulation. In recent times, polymer foam is used as an intermediate layer in glass insulation systems in aluminum thermal conductivity. Since it is exposed to atmospheric moisture during glass insulation production, Purmol® is used. At the same time, Purmol® adsorbs moisture entering between the panes during the insulation system production.

                Yasin Karamehmetoğlu Chemist Sales Manager Damlanem Kimya Sanayi Ticaret A.Ş.