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Thermoplastic Elastomers
This is a group between rubber and thermoplastic polymers, called thermoplastic elastomers. These copolymers consist of hard polymer segments in a matrix of soft amorphous polymers. These segments are physically bound to each other, giving the elastic properties. In contradiction to rubber and thermosets, the binding between the molecules is reversible by melting and cooling. Changing the ratio of hard segments in the copolymer will increase or decrease the strength, stiffness and hardness of the polymer.
TPE-U (Thermoplastic Elastomer Urethane)
TPE-U is a group of polymers often referred to as PUR, with a very wide range of properties. The two main types of TPE-U are either polyester or polyether based. The polyether based TPE-U is more elastic, and has a higher resistance to hydrolysis and microorganisms. The hard segment in the copolymer is of a crystalline nature.
- Hardness ranges from shore 75A to 75D.
- Good biocompatibility.
- Softens in vivo.
- Excellent abrasion resistance.
TPE-A (Thermoplastic Elastomer Amide)
TPE-A are copolymers of polyamide with either polyether, polyester or polyether ester. The hard segments in the copolymer are formed by the semi-crystalline polyamide segments in the copolymer . PolyEterBlockAmide (PEBA), often referred to as PEBAX®, is a commonly used TPE-A in medical applications.
- Hardness ranges from Shore 75A to 75D
- High abrasion resistance.
- Good biocompatibility.
TPE-E (Thermoplastic Elastomer Ester)
Ester based thermoplastic elastomer, is a copolymer of polyether-esters or polyester-esters.
- Hardness ranges from Shore 35D to 74D
- Excellent chemical resistance.
- High fatigue resistance.
For more information about properties of different themoplastic elastomers, see
 Summary_Properties.pdf
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