Energy savings plus mechanical reinforcement and rheology control

Simplified 1K Moisture Curing Polyurethane Sealant

Adhesives Formulation

Applicable Type

Sealants

Applicable Base Polymer

PU-Prepolymers

Applicable Industrial Sectors

Buildings & constructions , Industrial Assembly , Transportation (excl. Automotive)

Applicable Base Polymer Properties

Single-component moisture cured polyurethanes have become increasingly attractive to manufacturers of adhesives, sealants and coatings. Formulations based on polyurethane prepolymers offer fast room temperature cure and good durability.

the sealants or adhesives are free of unreacted isocyanate, making for products that are less harmful to the environment. Benefits also include a broadening of the formulation latitude compared to conventional sealants. Desmodur E-21 is an aromatic polyisocyanate prepolymer based on diphenylmethane diisocyanate (MDI).

Typical Formulation Ingredients

Phase

Ingredient

Parts by weight

Polyurethane prepolymer (Desmodur E-21, Bayer)

xxxx

Plasticizer (Mesamoll, Lanxess)

xxxx

Fumed silica (Aerosil R-202, Evonik)

xxx

Processing

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Resulting Properties

Plasticizer-free and of relatively low viscosity, Desmodur E-21 is an excellent base resin for low modulus sealants in building and construction applications where good elastic recovery is required. The table above provides a simplified formulation for a one-component polyurethane sealant that cures via reaction with environmental moisture.

Excellent primerless adhesion to glass, aluminum and other metals
Excellent durability and joint movement
Good tensile strength and elasticity
Freedom to formulate low modulus/high elongation or high modulus/low elongation systems
Excellent solvent resistance
Immediate paintability

Evonik