What is Polyurethane - Polyurethane Properties

Polyurethane is a versatile class of synthetic polymers formed by reacting isocyanates with polyols, resulting in materials that can be precisely engineered for performance and durability. Rather than a single substance, polyurethane encompasses a broad family of polymers. From rigid and flexible foams to coatings, adhesives, elastomers, and fibers, each formulation is crafted to deliver tailored performance in diverse applications. This flexibility in formulation highlights the exceptional properties of polyurethane, allowing one material type to exhibit characteristics such as high abrasion resistance, thermal insulation, impact tolerance, chemical resistance, and a customizable range of hardness and elasticity.

The benefits of polyurethane are just as multifaceted: it offers cost-effective tooling, enhanced lifespan, weight savings, and energy efficiency—especially in insulation—while maintaining excellent mechanical and environmental durability in challenging conditions. Whether used in machinery components, automotive interiors, building insulation, or adhesives, polyurethane brings a compelling combination of resilience, adaptability, and performance that no single-material alternative can match.

Common Forms of Polyurethane:

Polyurethane exists in various forms, each tailored to specific applications, showcasing its versatility. While there are many classes of polyurethane products, FallLine only manufactures cast elastomer parts and products.

Foams: Flexible foams are used in furniture cushioning and automotive seating for comfort and support, while rigid foams provide excellent thermal insulation in construction and refrigeration.
Elastomers: Elastomers offer flexibility and durability for use in wheels, rollers, and industrial parts, providing superior impact and abrasion resistance.
Coatings and Sealants: These are applied to surfaces like floors and machinery to protect against wear, weather, and chemical exposure, extending the lifespan of the materials.
Adhesives: Polyurethane adhesives are valued in woodworking, construction, and automotive industries for their strong bonds and versatility with various substrates.
Fibers: Used in textiles, polyurethane fibers are found in spandex and stretch fabrics, offering elasticity and comfort in clothing and medical applications.
Mechanical Parts: Polyurethane is used in gears, bushings, and gaskets, valued for its resistance to wear and ability to withstand mechanical stress.

How Polyurethane is Created

Polyurethane synthesis involves a chemical reaction between diisocyanates and polyols, leading to a versatile polymer.

The Chemical Reaction

1. Raw Materials:

Diisocyanates: Contain isocyanate groups, such as MDI and TDI.
Polyols: Contain hydroxyl groups (-OH), available in polyester or polyether forms.

2. Polymerization Process:

Step 1: The isocyanate group reacts with the polyol.
Step 2: This reaction forms a urethane linkage

Final Outcome

Polymer Chains: The repeating urethane linkages form robust chains with customizable segments.
Versatility: Adjusting the diisocyanates and polyols allows tailoring of characteristics like flexibility and resistance.
Applications: This material is used for cast elastomers, foams, insulation, automotive parts, coatings, and adhesives. Learn more

Why Polyurethane?

Chances are that you are not a scientist, but more likely an engineer, buyer or manufacturer seeking to reduce cost and improve performance in your machinery or products. Polyurethanes are materials that offer a dynamic range of properties that can be tailored to an extraordinarily wide range of applications. This structural adaptability makes polyurethane essential across various industries for its performance and durability.

The Superior Choice

Polyurethanes are often a superior choice to plastic, rubber, and steel because they can embody the characteristics of all three. Polyurethanes can be formulated to resist chemicals, water, shearing and tearing, impact, heat and cold, and many other elements that cause traditional parts to wear prematurely and eventually fail.

The experts at FallLine are ready to assist you with your custom molded polyurethane product. Contact us today!

Custom Polyurethane Molding

Properties & Advantages of Polyurethane

Cost Efficiency

Tooling for casting polyurethane parts is very economical, costing significantly less than molds for rubber or plastic. Polyurethane parts typically provide a substantial increase in product life over other materials, which translates to a better overall value.

Machinability

Polyurethanes can be machined with traditional tools, making polyurethane an economical choice for low production runs or prototype parts.

Bonding

Through proper treatment of the bonding surface, a high strength bond can be achieved to metals, polyurethanes and other substrates. In some cases, the bond strength can exceed the tear strength of the polyurethane itself.

Durometer

Durometer is the measurement of a material’s hardness. Polyurethanes range from 10 Shore A, about as soft as a rubber band, to 80 Shore D, about as hard as a bowling ball.

Abrasion Resistance

Reflects the ability to resist frictional wear. Generally, polyurethane exhibits excellent abrasion resistance, offering substantially better performance than rubber, plastic and many metals.

Tensile Strength

The measure of an elastomer’s ultimate strength when enough tension is applied to cause failure. Generally, polyurethane exhibits a high tensile strength when compared to other elastomers.

Temperature Resistance

Polyurethanes operate within a wide temperature range. Some elastomer formulations can retain their flexibility at temperatures below -60°F, while others can operate continually at temperatures in excess of 200°F.

Water Resistance

Polyurethanes can be formulated to resist the absorption of water. In fact, weight and swell are practically negligible even after prolonged exposure. This makes polyurethane an excellent choice in which tight tolerances must be maintained in wet conditions.

Chemical Resistance

Polyurethanes display excellent resistance to oil, grease and a wide range of chemicals; however, prolonged exposure to caustic acids, solvents and other heavy corrosives should be avoided. Simulated environmental testing should be performed to ensure part life.