Background information about Polyurethane as a material
As mentioned, polyurethane (polycarbamates) belong to a class of compounds known as polymers. Polymers are macromolecules; they’re made from smaller and repeating units known as monomers. They often consist of a main long-chain backbone molecule with smaller attached side groups.
A synthetic polymer, such as polyurethane, is created by reacting monomers in reaction vessels. The step (condensation reaction) that produces polyurethane starts by invoking a chemical reaction between disoyanate and a diol that produces a reactive alcohol and a reactive disocyanate, which continues to further react with other monomers to produce a larger and long molecule.
Polyurethane’s chemistry was first researched by German chemist Friedrich Bayer in the late 1930s. He produced early prototypes of the material, mainly through reacting toluene diisocyanate with dihydric alcohols.
From this research, the one of the first crystalline polyurethane fibers (Perlon U) was developed. By the mid-1950s, the first commercial production of flexible polyurethane foam had started; by the end of the decade, other forms of pliable polyurethane were well into development and production.
Various raw materials are used to produce polyurethane. These materials include pre-polymers, monomers, colorants and stabilizers that protect the polymer’s integrity.
TPU and TPE Characteristics
– Rubber touch feel
– Wide range of uses
– Hard wearing
Polyurethane is the primary material used in polyurethane injection moulding. It’s a type of linear polymer with a molecular basis containing several carbonate groups (-NHCO2). Collectively known as urethane, they’re produced through a chemical reaction that occurs between a polyol and diiscoyanate. Polyurethane is notably used in various applications, including building insulation, adhesives, solid plastics, surface coatings and athletic apparel.
Thermoplastic polyurethane (TPU) and Thermoplastic elastomers (TPE) are similar in properties of the material – in fact TPU is one of the six commercial classes of TPE. We can go into more depth about the properties and discuss which type of polyurethane is the best for the product or component to be molded. TPU and TPE parts act as protection (friction buffer) are most common applied on smartphone cases, testing devices cases, tooth brush handles.
Design and Applications
Here’s a brief breakdown of polyurethane applications:
Elastomers are used for their strength, flexibility and shock absorption. Used as base materials for footwear, automobile parts and other mechanical goods. TPE injection moulding and TPU injection moulding is a popular material of choice.
Polyurethane coatings are used for their solvent degradation resistance and impact resistance. They’re commonly used on dance floors and in bowling alleys. Water-based versions are used for painting automobiles, aircraft and other industrial equipment.
Cross-linked polyurethanes are used to produce insulation in the form of laminate insulation or board insulation. Laminates are used extensively in commercial roofing and other parts of the construction industry.
Flexible polyurethane foams, as mentioned, are mainly used as cushioning for furniture and mattresses. They’re also used as padding or cushioning for other applications, made into sponges or other cleaning supplies and some forms of packaging.