Category: Thermoplastic Polyurethane Elastomer

Thermoplastic polyurethane elastomer, also known as TPU, is a type of (AB)n block linear polymer. A represents a high molecular weight (1000~6000) polyester or polyether, and B represents a diol containing 2~12 straight chain carbon atoms. The chemical structure between AB segments is diisocyanate. Thermoplastic polyurethane rubber relies on intermolecular hydrogen bonding cross-linking or mild cross-linking between macromolecular chains. With the increase or decrease of temperature, these two cross-linking structures have reversibility. In the molten state or solution state, the intermolecular force between molecules weakens, and after cooling or solvent evaporation, strong intermolecular force connects them together to restore the original solid performance. Typical TPU includes spandex, etc.

Brief Introduction

Thermoplastic polyurethane elastomer (TPU) is a type of elastic material that can be plasticized by heating and dissolved by solvents. It has excellent comprehensive properties such as high strength, high toughness, wear resistance, and oil resistance, as well as good processing performance. It is widely used in industries such as national defense, medical, and food.

With its excellent performance and wide application, thermoplastic polyurethane elastomer has become one of the important thermoplastic elastomer materials. Its molecules are basically linear and have little or no chemical cross-linking. There are many physical cross-links composed of hydrogen bonds between linear polyurethane molecular chains, and hydrogen bonds play a role in strengthening their morphology, thereby endowing many excellent properties such as high modulus, high strength, excellent wear resistance, chemical resistance, hydrolysis resistance, high and low temperature resistance, and mold resistance. These excellent properties make thermoplastic polyurethane widely used in many fields such as footwear, cables, clothing, automobiles, medical and health, pipes, films, and sheets. The final product generally does not require vulcanization cross-linking, which can shorten the reaction cycle and reduce energy consumption. Since it is basically a linear structure polymer, the same technology and equipment as thermoplastic plastics can be used for processing, such as injection molding, extrusion, blow molding, and calendering, especially suitable for mass production of medium and small-sized parts. Waste materials can be recycled and reused, and different additives or fillers can be used in the production or processing process to improve certain physical properties and reduce costs.

Classification

Thermoplastic polyurethane elastomers can be divided into two types: polyester type and polyether type. They are white irregular spherical or columnar particles with a density of 1.10~1.25g/cm3. The relative density of polyether type is smaller than that of polyester type. The glass transition temperature of polyether type is 100.6~106.1℃, while that of polyester type is 108.9~122.8℃. The brittle temperature of both polyether and polyester types is lower than -62℃, and the low-temperature resistance of polyether type is better than that of polyester type.

Characteristic

The outstanding characteristics of thermoplastic polyurethane elastomers are excellent wear resistance, extremely good ozone resistance, high hardness, high strength, good elasticity, and low-temperature resistance. They also have good oil resistance, chemical resistance, and environmental resistance. In humid environments, the hydrolysis stability of polyether type is far superior to that of polyester type.

New Technologies and New Uses

TPU is a rapidly developing industry, with new technologies, products, and applications emerging constantly. TPU has been widely used in various industries, including footwear, clothing, pipes, films and sheets, cables, automobiles, construction, healthcare, defense, and sports and leisure. TPU is recognized as a green and environmentally friendly new type of polymer material with excellent performance. Currently, TPU is mainly used in low-end consumption, while high-end consumption is dominated by some multinational companies, including Germany’s Bayer and BASF, and the United States’ Lubrizol and Huntsman, which are increasing their research and development efforts on new products. High value-added TPU products are constantly being developed and put into the market, and TPU materials have become one of the fastest-growing thermoplastic materials.

• Footwear: sports shoe logos, sports shoe air cushions, hiking shoes, snow boots, golf shoes, ice skates, and fabric and lining materials.
• Clothing: ski jackets, raincoats, windbreakers, cold-proof jackets, field uniforms, diapers, physiological pants, and fabric composite materials (waterproof and breathable).
• Medical: surgical gowns, hats, shoes, hospital pads, ice bags, bandages, plasma bags, surgical bandages, masks, and fabric and lining materials, surgical bed airbags.
• Defense products: aircraft fuel tanks, weapon storage films, tent windows, military water bags, life jackets, inflatable boats, and fabric and lining materials, airbags.
• Sports equipment: soccer surfaces and inner tubes, inflatable beds, water bags, ski gloves (waterproof bags), diving suits, ski jackets, swimsuits, skis, logos, airbags, sports shirts, slimming clothes, and fabric and lining materials.
• Industrial products: speaker drum paper rubber edges, waterproof strips, sound insulation materials, fireproof materials, fireproof clothing, fireproof cloth, and fabric and lining composite materials, wire and cable outer sheath materials.
• Other uses: mobile phone keys, plastic inflatable toys, bed sheets, tablecloths, shower curtains, furniture fabrics, aprons, pianos, computer keyboards, film coatings, and fabric and lining materials.