Polyurethanes

Polyurethanes (also shortened to PUR or PU) are plastics or synthetic resins. Polyurethanes are usually used as 2-component materials consisting of resin and hardener. They can be formulated and used both as compact materials (open-cell or closed-cell) and in the form of foams.

Compact materials are primarily used to protect components in the electronics industry. A large number of chemical raw materials, additives, fillers and other aggregates make it possible to realize a wide range of application profiles.

We are your experts for customized casting resin systems and can produce casting compounds with product properties ranging from hard to soft, from tough to brittle, from low viscosity to high viscosity/stability, from very fast to slow curing, from hydrophilic to hydrophobic. It is also possible to incorporate special properties such as flame retardancy, thermal conduction or thermal insulation, compressibility and many more.

For more detailed information, please refer to our comprehensive polyurethane instruction.

Product overview - Polyurethane cast resins

Below you will find a selection of our polyurethane casting resins. Many other modifications are possible on request. Clicking on the product name will take you to the corresponding product page including all data sheets.

Produkt

Property 1

Property 2

Property 3

ISO-PUR® BD50-12+
Low Viscous PolyBD Cast resin with good temperature cycling properties

Property 1

5,6 : 1 pbw

Property 2

approx. 600 mPas

Property 3

Shore A ca. 33

Abb. 1 Aufbau eines nicht quervernetzten Polyurethans

We all use products containing polyurethane on a daily basis. PU cast resins can be found in the furniture industry in the form of mattresses or upholstery, as well as in vehicle interiors. They are also indispensable in the shoe industry, especially in shoe soles. In the building materials sector, polyethane casting resins can be found in a wide variety of applications, either in floor coatings or in insulation and assembly foams. In all industries the use of polyurethane protective coatings represents a very broad and elementary field of application.

Chemically, polyurethanes are made up of polyols and isocyanates (Fig. 1), whereby polymers with varying degrees of cross-linking are generally sought. In contrast to many hotmelt adhesives, these are not thermoplastic. A large number of industrial polyols (polyether, polyester, polybutadiene, etc.) and isocyanates are available for the production of polyurethanes, allowing a wide variety of products and properties to be customized, so to speak.

Another important chemical reaction of the isocyanate group is its reaction with water, which produces carbon dioxide and an amine. For this reason, when casting polyurethanes, especially for solid components, care must be taken to work under water-free conditions as far as possible in order to achieve an optimum, bubble-free result. The addition of water-adsorbing fillers, so-called zeolites, can bind residual moisture from the raw materials used, which makes application easier.

CO₂ formation is used specifically in the formation of foams (insulation foams, mattresses, shoe soles), and existing bubbles reinforce this effect.

Through the formation of amines, NCO-terminated prepolymers can also cure with atmospheric moisture, making 1-component systems for sealants and adhesives possible.