Untersuchung der mechanischen Rezyklierbarkeit von technischen Biokunststoffen

Translated title of the contribution: Evaluation of the mechanical recyclability of technical biopolymers

Eva Christina Blees

Research output: ThesisMaster's Thesis

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Abstract

Technical biopolymers exhibit extraordinary performance characteristics and are sustainable alternatives to conventional plastics for numerous applications. However, recycling and recyclability of technical biopolymers has not been studied systematically and comprehensively so far. Hence, this study aims to assess the mechanical recyclability of technical biopolymers polyamide 6.10 (PA6.10), poly(butylene succinate) (PBS), and poly(trimethylene terephthalate (PTT), cellulose acetate butyrate (CAB), and a blend of poly(hydroxybutyrate-co-valerate) and poly(butylene adipate-co-terephthalate) (PHBV/PBAT). The simulation of the mechanical recycling process (up to sevenfold iteration) included drying of the materials followed by extrusion and granulation. The effect of repeated processing on material performance characteristics was analyzed by spectroscopic techniques, differential scanning calorimetry, dynamic-mechanical analysis and tensile testing. The results clearly demonstrate the mechanical recyclability of technical biopolymers is high. However, this requires adequate process control and thorough adjustment of processing parameters. Repeated processing resulted in modifications in morphology along with significant yellowing in PA 6.10. However, mechanical performance characteristics were not significantly affected by these changes in chemical and physical structure. For PBS a reduction in molecular weight as well as changes in crystalline morphology were observed with increasing number of processing cycles. Again, mechanical performance characteristics were not affected by repeated processing. Repeated processing initiated hydrolytic degradation in PTT. Nevertheless, mechanical performance characteristics were impaired to a low extent. Hydrolytic degradation was also observed for CAB. Reduced molecular weight yielded a decrease in stiffness and an increase in strain at break. Molecular weight was also significantly reduced for PHBV/PBAT already after one processing cycle, which caused a deterioration of mechanical performance properties and significant embrittlement.
Translated title of the contributionEvaluation of the mechanical recyclability of technical biopolymers
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Pinter, Gerald, Supervisor (internal)
  • Resch-Fauster, Katharina, Co-Supervisor (internal)
  • Klein, Andrea, Co-Supervisor (internal)
Award date1 Jul 2016
Publication statusPublished - 2016

Bibliographical note

embargoed until null

Keywords

  • biopolymers
  • bioplastics
  • recycling
  • multiple processing
  • processing-related degradation

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