DuPont Hytrel® polyester TPEs

In DuPont Hytrel polyester TPEs, the resin is a block copolymer. The hard phase is polybutylene terephthalate (PBT). The soft segments are long-chain polyether glycols. 

Poly(ether-ester) (PEE) copolymers obtained by modification of poly(ethyl-ene terephthalate) with up to 20 wt% of poly(ethylene ether) glycol was first described by Coleman [8]. Subsequently, the DuPont Co. developed poly(ether-ester) elastomers, which were commercially introduced in 1972 under the trade name Hytrel [4,9]. The polyester thermoplastic elastomers are nowadays produced by several companies. Apart from DuPont, these are DSM, The Netherlands (Arnitel ), General Electric, USA (homed ), Hoechst Celanese, USA (Retiflex ), Toyobo, Japan (Pelprene ), Elana, Poland (Elitel ) [2,10]. The synthesis, chemical structure, physical properties, and some new applications of polyester TPE are discussed in this chapter (about the development of TPE, see also Chapter 1, while details on some commercial TPE products can be found in Chapter 17). 

The three major types of TPEs are block copolymers such as SEES (styrene-ethylene-butylene-styrene block copolymer) (Kraton by Kraton Polymer), polyether— polyester (Hytrel by DuPont), rubber/plasticblends (900 series Sumitomo Chemical), and dynamically vulcanized rubber/plastic alloys (Innoprene by Kumho Polychem, Santo prene by Exxon-Mobil, Sarlink by DSM, Unipene byTeknor Apex). Figure 3.28 shows the cost versus general performance comparison for different TPEs [31]. 

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