Difference Between Urethane and Polyurethane (With Table)

Urethane and Polyurethane are chemicals that are often confused with each other because of their similar chemical properties, which are used to create or formulate a product. The same is the case with the chemicals of Urethane and Polyurethane, which are frequently used as replacements for each other. Educating oneself about the differences between these chemicals shall be helpful while purchasing these chemicals for work at home or commercial work. 

Urethane vs Polyurethane

The difference between Urethane and Polyurethane is that the chemical Urethane is a repeating unit of atoms that are arranged in a specific order. The atoms of oxygen, nitrogen, carbon, hydrogen make up Urethane. Whereas Polyurethane is a chemical compound that comprises the reacting atom units of Urethane.

Urethane is a crystallized compound that is usually a pale and scentless, crystalline chemical compound that releases fumes of nitrogen oxides that are dangerous. They are released when nitrogen oxides are smelted until decomposition. Urethane is largely utilised in the composition of amino resins but is also utilised in the production of pesticides, fumigants, cosmetic products and pharmaceutical products.

Polyurethane is a chemical compound that is comprised of organic atom units of urethane that is made up through the process of polymerization. Polyurethane is a compound that is a hard material and is often used to develop paints to provide a shiny finish, and also used to design footwear and foams which because of its stiff element. Polyurethane compounds are durable and also mainly used in commercial and residential furniture products.

Comparison Table Between Urethane and Polyurethane

Parameters of ComparisonUrethanePolyurethane
DefinitionUrethane is a crystalline compound that is made out of carbonic acid. Polyurethane is a chemical compound that is formed after the polymerization of a bunch of urethane units. 
UsesUrethane is mainly used in insecticides, pesticides and incorporated in pharmaceutical products as well as cosmetic products.Polyurethane is a solid compound used in making footwear and foam and used in paints for shine.
ToxicityUrethane is slightly toxic in nature. Researches have proved that urethane has caused cancer in tiny animals and causes nausea in humans when taken orally in the form of medicines. Polyurethane is not as toxic when someone comes in contact with it.
MalleabilityUrethane is a chemical compound that is very soft, flexible and malleable and has a melting point is 50.Polyurethane is a stiff and hard material that does not have a melting point.
DurabilityUrethane is more resistant to scratches, is more durable and safer to use in paints.Polyurethane is not as durable and environmentally safe as compared to Urethane.

What is Urethane?

Urethane is a compound that was designed in the 1950s-1960s. Urethane is made up of units of R1-O-(CO) NR2-, that are each created out of amide and esters of carbonic acid. Urethane is a compound that can be moulded into varying shapes and sizes because of its docile, flexibility and malleability. The crystalline compound is used for various purposes. Although the Urethane compound is mostly utilised in insecticides, pesticides, veterinary medicines, and pharmaceutical products.

 However, this chemical compound is not deadly on humans, although the compound Urethane can turn out to be toxic when animals come in contact with it. Research has proved that Urethane has caused cancer in animals who consume the compound orally. The chemical compound is odourless and colourless but has a metallic and bitter flavour. As urethane is used to make medicine, the intake of urethane material can make few patients nauseous. It is a durable material that has load-bearing and compressing attributes, a good friction coefficient that helps maintain its shape and size after a long duration of wear and tear.

Urethane is also used as a paint of a protection cover over enamel because of its durability. Urethane has protective properties, which have a protective covering on furniture from harmful ultraviolet rays, also a reason why it is utilised in automobiles. Some urethane paints contain polyurethane, but the two chemical compounds are quite different to each other. Urethane paints are very flexible, so it is very difficult to make them adhere to particular surfaces or on paintbrushes.

This quality of Urethane paints has innovated the unique urethane brushes which are specifically used for urethane paints. The surfaces are sanded roughly before Urethane paint is applied to the surface. There are two ways Urethane paint is applied in two particular ways. Firstly, applying urethane paint by diluting it and apply it on the surface in multiple flat sheets or apply a heavy coat and “tip” utilising an almost dry paintbrush.

What is Polyurethane?

Polyurethane is a chemical compound that is hard and stiff, which is why they are mostly employed in solid products such as footwear, foams, etc. Polyurethane is also utilised in certain types of paints when the surfaces require special coating as well as shine. Polyurethane coatings can be satin or glossy in finish. Regular polyurethane paint may require around 8 hours to dry, which means that the surface will be receptive to dust particles found in the air.

This is a reason why water-based polyurethane was invented for a faster drying process. Polyurethane chemical compound has fastening attributes which bond it with metals as well as plastic and plays as a protective coating from ultraviolet rays and other environmental issues. Polyurethane has also proved to be durable against hydrocarbon solvents.

As compared to urethanes, polyurethanes are tougher and have stronger wear and tear biases than urethanes, but they are mainly put to use for indoor furniture and products instead of outdoor products. Polyurethane coatings are the more suitable choice for more durable pieces, and they are very favourable over rubber or even steel. They also have more satisfying compression and ageing attributes compared to urethanes which is why they are used in paints.

Main Differences Between Urethane and Polyurethane

  1. Urethane is a crystalline compound that is made out of carbonic acid, whereas polyurethane is a chemical compound that is formed after the polymerization of a bunch of urethane units. 
  2. Urethane is mainly used in insecticides, pesticides and incorporated in pharmaceutical products as well as cosmetic products, whereas Polyurethane being a solid compound, is used in making footwear, foam and also used in paints for shine.
  3. Urethane is slightly toxic in nature. Researches have proved that urethane has caused cancer in tiny animals and causes nausea in humans when taken orally in the form of medicines. Polyurethane is not as toxic.
  4. Urethane is a chemical compound that is very soft, flexible and malleable and has a melting point is 50. Meanwhile, polyurethane is a stiff and hard material that does not have a melting point.
  5. Urethane is more resistant to scratches, is more durable and safer to use in paints as compared to when Polyurethane is mixed with paint. 

Conclusion

In conclusion, the two chemical compounds of Urethane and Polyurethane are different in structure and used for different purposes. Knowing the correct differences and properties of these chemical compounds is helpful when buying them for indoor furniture, automobiles and paints. The Polyurethane compound contains urethane groups that are higher in number.

Polyurethanes are also a part of the elastic polymers family that is also known as Rubber. The polyurethane chemical is created through the composed joining of various urethane groups that eventually makes them the poly-urethane compound. The higher number of urethane compounds makes polyurethane a far more durable elastomer.

References

  1. https://www.sciencedirect.com/science/article/pii/S0032386115300100
  2. https://www.sciencedirect.com/science/article/pii/S0032386198007265
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