Developed in the 1930s, polyurethane has been a highly versatile key polymer. Polyurethane has been used for building insulation, adhesives, surface coatings, solid plastics, and even athletic apparel. Due to its versatility in terms of uses you may wonder, how is polyurethane made? Below you will find helpful information about the polymer and how it is made.
How Is Polyurethane Made?
The Molecular Structure of Polyurethane
In order to effectively understand how polyurethane is made, it’s important to understand its molecular structure. Polyurethane belongs to a larger class of compounds that are referred to as “polymers.” Polymers are macromolecules made up of smaller units, known as “monomers.” Monomers consist of a primary long-chain backbone molecule that also has attached side groups.
Also referred to as “polycarbamates,” polyurethane is a linear polymer that has a molecular backbone that contains carbamate groups. The carbamate groups are referred to as “urethanes” and are produced through a chemical reaction. The chemical reaction is between a polypol and a diisocyanate.
How Is Polyurethane Made?
Polyurethane is produced by reacting monomers through a reaction vessel. The reaction is referred to as “condensation” and is the step necessary to produce polyurethane. The monomers present in the chemical reaction contain reacting end groups, including diisocyanate and diol. The first step in the condensation process links the two molecules together and leaves a reactive alcohol and isocyanate on either side. The two react further to create a larger and longer molecule. The process is rapid and yields high molecular weight materials at just room temperature. Due to the variety of uses of polyurethane, it also contains other functional groups in the molecule. Some include esters, ethers, amides, and urea groups.
Forms of Polyurethane
Polyurethanes are produced in four different forms, including elastomers, coatings, flexible foams, and cross-linked foams.
Elastomers: Polyurethane elastomers are raw materials that can be stretched out. They eventually return to their original shape. This type of polyurethane application is useful in projects that require flexibility, strength, shock absorption, and abrasion resistance. These are most often used in products such as specialty seals, roller skate wheels, mechanical goods, cable jackets, ski boots, and auto parts.
Coatings: Polyurethane coatings are resistant to solvent degradation. They also have good impact resistance as they are often used on surfaces that require abrasion resistance, flexibility, adhesion, fast curing, and chemical resistance. Polyurethane coatings are often used on dance floors and bowling alleys, while water-based coatings are used for aircraft and automobile paint.
Flexible Foams: Polyurethane flexible foams offer high impact strength. In fact, flexible foams are the largest market for polyurethanes as it is highly versatile. They are often used in luxury mattress and seat cushions. Semi-flexible foams are used in car dashboards, door liners, packaging, sponges, squeegees, interior padding, and carpet underlay.
Cross-linked Foams: Cross-linked foams are similar to flexible foams in terms of their use. They are often used to produce insulation in the form of laminate or boards. Laminates are heavily used in the roofing industry.
Real Seal Specialty Seals
If you are considering polyurethane seals, Real Seal is the top polyurethane seal and component product producer. They are well-known for using strong materials, including polyurethane, in addition to having extensive product expertise. They are effective in high pressure hydraulic and water applications, nail or riveting equipment, and in parts that require quick disconnects.
Real Seal’s polyurethane O-rings perform well in a number of applications and environments as it is long-lasting and effective in resisting abrasion. It is an effective engineering material and can be customized to meet your needs. Contact the team at Real Seal today for any of your specialty seal needs.
