Product Details
Polyurethanes find extensive use in water-borne, solvent-borne and hot-melt adhesive products. Additionally, they can be formulated as either thermoplastic or reactive types, and supplied in one-component or two-component systems. The chemical characteristics of urethane structures give polyurethanes their broad adaptability and tunable performance. Typically produced by the condensation of isocyanates with alcohols, polyurethanes may also form via polymerization between polyisocyanates and hydroxyl-containing substances such as polyols, polyesters and polyethers.
At present, the primary commercial polyurethane products cover foams, adhesives, coatings and elastomers.
Products Description
Polyurethane FoamsManufactured predominantly from diisocyanates, alongside polyether or polyester-based polyols, catalysts, foaming agents, foam stabilizers and other additives, polyurethane foams are available in flexible and rigid grades. Three mainstream foaming technologies are adopted: prepolymerization, semi-prepolymerization and the one-step process. Prepolymerization and semi-prepolymerization are suited to small-scale manufacturing, whereas the one-step method is ideal for mass production. Both rigid and flexible polyether or polyester-based polyurethane foams fall under thermosetting plastics, whose performance differs greatly based on raw material selection and formula design. Featuring oil resistance, cold resistance, thermal insulation and sound-absorbing properties, they serve as thermal insulators, electrical insulators, sound-proof structural components, leak-proof materials, shock-absorbing packaging, noise-reducing materials, cushioning media, as well as dust-removal and filtering materials.
Polyurethane AdhesivesThese are two-component formulations consisting of polyisocyanates and hydroxyl-containing polyester compounds, which are blended on-site prior to application. They deliver robust bonding strength for multiple substrates, and the cured adhesive maintains stable performance against water, mineral oils and atmospheric exposure. They are applied to bond metals, glass, plastics and ceramics in construction, mechanical engineering and aerospace sectors.
Polyurethane CoatingsDiverse polyurethane coatings can be synthesized by matching different isocyanates with tailored polyesters, polyethers and polyols. They are generally categorized into two component and one-component types. Two-component coatings are polyether-based, formed by direct mixing of polyisocyanates and polyethers. One-component variants are unsaturated-polyester-based, including blocked, oil-modified and moisture-curing grades. Common application techniques include impregnation, spraying and electrodeposition. The finished coatings provide superior electrical insulation, strong adhesion, outstanding wear resistance, oil resistance, water resistance and tolerance to inorganic acid vapors, making them suitable for concrete structures, chemical equipment, aircraft components and furniture.
Polyurethane ElastomersPolyurethanes can be engineered to display elastic behavior within specific temperature ranges, known as polyurethane elastomers. Bayer AG of Germany pioneered the synthesis of such materials globally. They are classified into three major types: castable, millable and thermoplastic elastomers. Combining rubber like elasticity with plastic style processability, they are also referred to as plastic elastomers. With excellent oil resistance, wear resistance, low temperature flexibility and anti aging performance, they are used in automotive bearings, high speed textile transmission belts, and oil field and geological exploration electrical cables.
