Polybutylensuccinat als potentieller Substitutionswerkstoff für Polypropylen und Polybuten

Research output: ThesisMaster's Thesis

Abstract

Within this study, the petrochemical-based, biodegradable biopolymer polybutylene succinate (PBS) was characterized and compared to the conventional, non-degradable polymers polypropylene (random-copolymer, PP) and polybutene (PB). The main aim was to investigate the potential of PBS to substitute PP and PB in structural applications. Samples from pressed plates as well as extruded films were compared. The main focus was on morphological, thermal, thermo-mechanical and mechanical material properties. Differential scanning calorimetry analysis exhibited the lowest melting temperature for PBS (117 °C), followed by PB (129 °C) and PP (143 °C). As a result, PBS showed the biggest thermal expansion at low temperatures. The melt-recrystallization model of PBS, as described in the literature, was more pronounced in film-samples than in plate-samples due to higher cooling rates during the extrusion process. The values for tensile-, compressive- and flexural modules of PBS were between those of PP and PB. Concerning the characteristic strength values, each material followed the expected trend (σtensile <σcomp <σflex). PBS exhibited the highest yield strength (38 MPa at room temperature) as well as the highest stress level at cold deformation. Furthermore, PBS exhibited the highest compressive stress level, which might be caused by its small-sized crystal superstructure. In accordance with this, crystal superstructures were not observable in PBS using polarisation microscopy, while PP and PB showed spherulitic superstructures. The brittle-ductile-transition of PBS corresponded to that of PB. The notch impact toughness was approximately the same. However, regarding the cracking, PBS performed similar to PP (unstable crack propagation and yielding with subsequent deep drawing, respectively). In general, the results of plate- and film-samples of PBS were comparable. However, the film-samples showed the so-called “stress-oscillation-effect” under tensile stress, which was not observable for plates.

Details

Translated title of the contributionPolybutylene succinate as a potential substitute for polypropylene and polybutene
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date1 Jul 2016
Publication statusPublished - 2016