Polyurethanes

What is polyurethane? Parameters, properties and possibilities.

Currently, polyurethanes (PU or PUR) are among the most popular and widely used polymers in the world.  They have a virtually unlimited range of applications, making them an integral part of modern life. They are used in the manufacture of both consumer and industrial goods.

They occur mainly in the form of polyurethane foams, obtained as a result of the reaction of multifunctional isocyanates with polyols (including polyether polyols) and many auxiliary substances. Thanks to this diversity, the possibilities for their synthesis are limited only by the imagination.

Compared to polyamides, they are more fusible, which makes the processing easier. However, they also have lower mechanical resistance. These properties make them often used in the production of spandex fibres (e.g. Lycra, elastane).

How are they made? History and modern production.

Polyurethanes are formed as a result of an addition polymerisation reaction between multifunctional isocyanates (component B) and polyols (component A), which are derived from crude oil. When the two components are mixed, a chemical reaction begins, resulting in the formation of polyurethanes, most often in the form of foam. Importantly, the polyol component in its advanced formulation contains carefully selected auxiliary substances, including catalysts, blowing agents (porophores), stabilisers and surfactants.

Their structure is distinguished by the presence of a urethane group [-O-CO-NH-] in the main chain.

By replacing some of the aforementioned components, modifying their concentration or adjusting the ratio of component A to component B in the mixture, it is possible to precisely control the physicomechanical properties of the resulting polyurethane. This makes it possible to obtain a material with varying stiffness, flexibility or strength.

These compounds were first obtained in 1937 as a result of scientific work by Bayer, a German chemist, and his research team. Even then, they gained enormous popularity in industry. However, this has been particularly evident over the last twenty years.

The polyurethane manufacturing process allows for the production of a relatively lightweight material, which makes it easier to process and subsequently transform and adapt to its final application without requiring large financial outlays. With the right additives, polyurethane can also be distinguished by its high level of hardness and resistance to damage.

Forms and properties of polyurethanes

Depending on the selection of basic raw materials and additives used in the production of polyurethane, it takes the form of foam in various states of aggregation or a solid form. This also affects the final form of products in which we can find polyurethanes, such as polyurethane foams, resins, fibres, adhesives, various types of coatings or urethane elastomers.

Polyurethane products are characterised by, among other things, good elasticity (even at high hardness), exceptional resistance to abrasion and tearing, and resistance to greases, oils and ultraviolet (UV) radiation. In addition, they are relatively easy (while maintaining high efficiency) to process industrially.

At the same time, finished PUR products do not deteriorate during intensive use. Therefore, they are increasingly used as substitutes for products made of rubber, wood, metal or ceramics. This contributes positively to a significant reduction in the overall weight of finished products.

The practical application of polyurethanes. What are they used for?

Due to their diverse properties, polyurethanes have gained the reputation of a unique group of polymers that are used in such areas of life and the economy as transport, construction, the furniture industry and mining.

They are also widely used in everyday life, including in the home, in the car, in sports equipment and even in clothing.

Polyurethane also offers a range of innovative solutions for industry. It not only effectively insulates production tanks and pipelines, but also bonds and seals joints on production lines.

Polyurethane foams are also used in the production of components for cars and other vehicles. Steering wheels, gear levers and dashboards are often made of polyurethane. Polyurethane also works well as an impact-absorbing material – under fenders or as acoustic insulation in headliners. People who value driving comfort should remember that flexible polyurethane foam is also used in car seats.

Polyurethane coatings are also widely used in transport. In the sports and recreation industry, integral polyurethane foam is used in the production of bicycle saddles, handles, mattresses and shoe soles.

In medicine, polyurethane-based materials are used in the production of operating tables and wheelchair components, while in mining, polyurethanes are used as one of the most durable binders. Polyurethane is also widely used in the furniture industry, for example in the production of mattresses and upholstered furniture.

Polyurethanes are present in seating found at airports, in aeroplanes, trains, buses and bicycles. In addition, products such as multi-coloured bath and dishwashing sponges, as well as foams for sealing windows and doors, are also made from polyurethanes.

PUR substances as thermal insulation materials

Among the applications mentioned, popular PUR foams deserve special attention. They are particularly known as universal thermal insulation materials that can be used to insulate various types of surfaces.

Among the wide range of products available on the market, we distinguish between open-cell and closed-cell polyurethane foams. This division results from differences in properties that affect the subsequent use of these materials.

When choosing the right solution, we should take into account the surface to be insulated, its condition and the possibility of moisture. We can also consider parameters such as adhesion, application speed and space savings compared to other materials.

We should also remember to choose the right insulation technology. One of the systems that has gained popularity in recent years is spray insulation. It is worth choosing polyurethane foams because they are the most effective heat insulators among other systems available on the market.

Very good thermal and acoustic insulation properties of polyurethane provide excellent thermal comfort and also protect against unwanted noise.

The use of polyurethane in industry

There is increasing talk that, due to its unique properties and increasingly widespread use, polyurethane may become the main raw material for many industries. It is already often a good alternative to metals, rubber, ceramics, wood and concrete. We should also not forget about its unique forms, such as the widely used foam.

Why is it worth it? Advantages of polyurethane-based substances.

Polyurethane products are distinguished by, among other things, good elasticity (even with high hardness), unique resistance to abrasion and tearing, and resistance to greases, oils and ultraviolet (UV) radiation. In addition, they are relatively easy (while maintaining high performance) to process industrially.

At the same time, finished PUR products are not damaged during intensive use. Hence, they are increasingly used as substitutes for rubber, wood, metal or ceramic products. This has a positive effect on the significant reduction of the total weight of finished products.

Chemical raw materials produced from polyurethanes. What does PCC offer?

To meet customer expectations, the PCC Group offers a range of specialised products for the production of polyurethane systems.

Our extensive and constantly growing portfolio of chemical raw materials includes polyether polyols (diols, triols), sugar polyols, Mannich polyols, sorbitol polyols and polymer polyols. In addition, there are also numerous additives, including cross-linking agents, emulsifiers and flame retardants. The latter are particularly important as they effectively reduce the flammability of polyurethane foams and allow an optimal balance to be achieved between reduced flammability and mechanical properties.

An important part of the product range offered by the PCC Group (a polyurethane manufacturer) are ready-made single- and two-component polyurethane systems used to produce the aforementioned types of foams, adhesives and sealants.

Systems for the production of semi-rigid and rigid polyurethane foams also occupy an important position. They are widely used, for example, as thermal insulation, acoustic insulation (PUR, PIR insulation), systems used in areas related to CASE applications (coatings, adhesives, sealants and elastomers), and even for the production of moulded flexible and integral polyurethane components.

Are you looking for polyurethanes (PUR) for industrial applications?

The PCC Group supplies high-quality chemicals for a wide range of industries. From the production of adhesives and sealants, through building insulation, to solutions for the automotive and furniture industries. Our products meet strict quality standards. Contact our team of experts to find the optimal solution.