Investigation of the Degradation Behavior of Polyurethane Film by Selected Bacteria and Their Influence on Thermal and Mechanical Properties

ABSTRACT This study shows the potential of four bacterial strains, namely Anerinibacillus migulanus , Bacillus subtilis , Pseudomonas fluorescens, and Streptomyces violaceoruber , for the degradation of commercial polyurethane film. The ability of the four bacterial strains to grow on a minimal medium containing a polyurethane film was investigated. The biodegradation of polyurethane was confirmed by a range of analytical techniques, including scanning electron microscopy, contact angle measurement, thermal analysis, as well as mechanical and rheological tests. After 7 days of biodegradation, first cracks, holes, and erosion were observed on the film surface. Following a test period of 28 days a maximum reduction of the water contact angle of 48% and an increase in polar surface energy content by 20.9 mN/m was observed with B. subtilis . The diiomethane contact angles observed for A. migulanus , P. fluorescens, and S. violaceoruber were reduced by 24.4%, 34.3%, and 17.7% respectively. The Fourier transform infrared spectroscopy demonstrated the disappearance of the C–H bending for all four bacterial strains. Finally, a mass reduction of 2.12% ± 0.51% was observed with A. migulanus after 28 days. Decrease in the elastic modulus and the elongation at break, at maintained strength upon degradation were confirmed by tensile tests using thermo‐mechanical analysis.