Differences between TPU and PUR

Thermoplastic Polyurethane (TPU) - Urethanes were the first major elastomers that could be processed by thermoplastic methods. TPUs do not have quite the heat resistance and compression-set resistance of the thermoset type of polyurethanes but most other properties are similar. Thermoplastic polyurethanes come in a wide range of hardness grades. Among elastomers, urethanes have outstanding abrasion resistance, low temperature flexibility is good, oil resistance is excellent, and urethanes rank among the best for load-bearing capability. Additives can improve dimensional stability and heat resistance, reduce friction, and increase flame retardancy, fungus resistance, and weatherability. Urethanes are a reaction product of a di-isocyanate and long and short chain polyether, polyester, or caprolactone glycols. The polyether types are slightly more expensive and have better hydrolytic stability and low-temperature flexibility than the polyester types. However, mechanical properties of the polyester type are generally higher. The caprolactones offer a good compromise between the ether and ester types.

Thermoplastic polyurethane (TPU) has been in use as a fabric coating material in the textile industry for over 30 years. Thermoplastic polyurethane's first application was as a replacement for PVC where the "look and feel" of PVC was of value but the performance of PVC was lacking in areas such as flex properties, plasticizer migration, abrasion resistance, low temperature properties, and cleanability.

Advantages

Abrasion Resistant , Hydrolysis Resistant, Oil Resistant , Low Temperature Resistant , Wear Resistant , Good Flexibility , Low Temperature Flexibility , Good Processability , Good Tear Strength , Chemical Resistant.

Disadvantages

- Chemical resistance (type dependent)

- Some suppliers note TPU grades having a relatively short shelf life

- Narrower hardness range than other TPEs

- Service temperature limited

- Drying required before processing

Polyurethane (PUR) - Polyurethanes are a large family of polymers with widely ranging properties and uses all based on the reaction product of an organic isocyanate with compounds containing a hydroxyl group. Polyurethanes may be thermosetting or thermoplastic, rigid and hard or flexible and soft, solid or cellular with great property variances. Principal applications are in coatings, elastomers and foams. Polyurethane has excellent abrasion resistance but high hysteresis. Rigid polyurethane foams have become widely used as insulation materials because of their combination of low heat transfer and good cost effectiveness. Use as insulation and other applications are restricted by an upper temperature capability of about 250°F. Polyurethanes do not survive well in direct sunlight or in contact with most organic solvents. Two types of polyurethane are common: polyester based and polyether based, with these backbone structures actually comprising a significant part of a so-called polyurethane resin.

Polyurethanes (PUR) were developed in Germany during World War II. Dr. Otto Bayer discovered the basic polyurethane chemistry in 1937 and I.G. Farben (Bayer) patented the process.

Advantages

Soft , Hydrolysis Resistant , Low Viscosity , Good Flexibility , Abrasion Resistant , Medium Hardness , Good Adhesion , Low Temperature Flexibility , Good Toughness , High Hardness. 

Disadvantages

- Poor thermal capability

- Poor weatherability

- Attacked by most solvents

- Utilize toxic isocyanates

- Flammable

Tags : M8 M12 TPU PUR CABLE