Thermoplastic copolyesters degradation

Polyether-based thermoplastic copolyesters show a tendency toward oxidative degradation and hydrolysis at elevated temperature, which makes the use of stabilizer necessary. The problem could be overcome by incorporation of polyolehnic soft segments in PBT-based copolyesters [31,32]. Schmalz et al. [33] have proposed recently a more useful technique to incorporate nonpolar segments in PBT-based copolyesters. This involves a conventional two-step melt polycondensation of hydroxyl-terminated PEO-PEB-PEO (synthesized by chain extension of hydroxyl-terminated hydrogenated polybutadienes with ethylene oxide) and PBT-based copolyesters. 

The effect of °Co y-ray irradiation on the mechanical properties, surface morphology, and fractography of blends of plasticized PVC and thermoplastic copolyester elastomer, Hytrel (E.I. Du Pont de Nemours Company, Inc., Wilmington, Delaware), have been studied by Thomas et al. [445]. Radiation has two major effects on the blend cross-linking of the Hytrel phase and degradation of PVC phase. Both effects are found more prominent at higher radiation dose. 

Thermoplastic copolyesters elastomers can be recycled by the conventional methods used for plastics, such as mechanical recycling, chemical degradation and sometimes by energy recovery, i.e. incineration. 

Albertsson, A.-C. and O. Ljungquist, Degradable polymers, li. Synthesis, characterization, and degradation of an aliphatic thermoplastic block copolyester. Journal of macromolecular science. Chemistry, A23(3) p. 411. 1986. 

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