Air Conditioning Connecting Pipe Air Conditioning Connecting Tube,Copper Connecting Pipe,Aluminium Copper Connecting Pipe for HVAC Suzhou Green New Material Technology Co., Ltd. , https://www.szgreenvip.com
**Source and Main Applications of Polyurethane**
Polyurethane, commonly referred to as PU, is a broad category of macromolecular materials that contain repeating carbamate groups (–NHCOO–) in their molecular structure. It is formed through the reaction between an organic diisocyanate or polyisocyanate and a diol or polyol. In addition to the carbamate group, polyurethane chains may also include other functional groups such as ether, ester, urea, biuret, or allophanate, depending on the specific formulation. The chemical name for polyurethane is "polyurethane," and it is widely used in various industries due to its versatile properties.
**Preparation and Synthesis**
Polyurethane is typically produced by the reaction between a diisocyanate or polyisocyanate and a polyol. This process results in a highly cross-linked polymer with unique mechanical and chemical characteristics. The basic chemical reaction involves the interaction between an isocyanate group (–N=C=O) and a hydroxyl group (–OH), forming a urethane linkage: –N=C=O + –OH → –NH–COO–. This reaction can be modified by varying the types of diisocyanates and polyols used, allowing for the creation of different polyurethane structures with tailored properties.
**Historical Development**
The discovery of polyurethane dates back to the 1930s when German chemist Otto Bayer first synthesized thermoplastic polyurethane (TPU). By the 1950s, TPU began to be used as a textile finishing agent in Europe, primarily in solvent-based coatings for dry finishes. As environmental concerns grew during the 1960s, water-based TPU coatings were introduced to reduce harmful emissions. Following this, the development of water-based polyurethane coatings accelerated in the 1970s, leading to widespread use in fabric coatings. Since the 1980s, significant advancements have been made in both research and application of TPU. Compared to international developments, domestic research into polyurethane-based textile finishers in some regions started later.
**Main Applications**
Depending on the raw materials used, polyurethanes can exhibit a wide range of physical and chemical properties. They are generally classified into two main types: polyester-based and polyether-based. These materials find extensive applications in the production of plastics, rubbers, fibers, rigid and flexible foams, adhesives, and coatings. Their versatility makes them suitable for use in automotive, construction, medical, and consumer goods industries. Additionally, polyurethanes are valued for their durability, flexibility, and resistance to abrasion, making them ideal for high-performance applications.
With continuous innovation and environmental improvements, polyurethane technology continues to evolve, offering sustainable and high-performance solutions across multiple sectors.