Polyester elastomers for biomedical application

Synthetic commodity polymers are generally hardly degradable in nature and cause ecological problems when disposed. Aromatic polyesters (PBT, PET, PEN) do not show any sign of degradation by microorganisms [173-175], but their 

The biocompatible dimerized fatty acid (DFA)-based poly(aliphatic-aromatic ester) elastomers (PED) have been synthesized and studied for biomedical applications by El Fray et al. [194-200]. The design of nanostructured elastomeric biomaterials (mimicking biological materials) has been realized by using renewable resources, i.e., DFA. They are prepared by transesterification and polycondensation from the melt (see Section 7). The exceptional properties of DFA, e.g., excellent resistance to oxidative and thermal degradation, allow the preparation of PEDs without the use of thermal (often irritating) stabilizers. This is a particularly important feature making these polymers environmentally friendly and additive-free. What is equally important, by the use of the same method and stabilizer-free conditions, it was possible to prepare specially modified PED copolymers with an increased surface hydrophobicity. 

FED copolymers tested at different temperatures reveal a significant effect at 37°C on the creep behavior. No significant influence, however, of the tested environment (air or liquid) was observed at 24°C. The nanostructured elastomeric biomaterials can be used for soft tissue reconstruction. 

The world demands for thermoplastic elastomers are forecast to expand by 7.5% per year to 2.6 million metric tons in 2006. TPEs will continue to find the majority of their applications as replacements for natural and synthetic rubbers, as well as rigid thermoplastics and metals. The global TPE industry will remain heavily concentrated in the USA, Western Europe and Japan, particularly for specialty materials, such as polyester elastomers. Prom the two trends of application of polyester elastomers as engineering plastics and functional materials, the second one is prioritized. In terms of engineering applications, the PEE production will remain closely related to the motor vehicle industry, sporting goods, hoses, and small household goods. 

Another important trend in TPE developments refer to biomedical applications. In addition to the chemistry of the polyester-based TPE and some of their physical properties reviewed in this chapter, specific applications are also considered, such as, e.g., in biomedical practice. In this respect, the TPE 

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