Biodegradability assessment of new types of lightweight polyurethanes

The subject of the bachelor thesis is biological degradation (biodegradation) of new types of lightweight polyurethanes which were synthesized for an agriculture application. The theoretical part summarises the utilization and biodegradation principles of polyurethanes and it outlines standardised methods for quantification of biodegradability potential. The biodegradability potential of the new materials was tested respirometrically according to the standard D 5988 under laboratory conditions for 150 days. Cellulose (the positive control) was mineralised of 30,25±2,28 %. The best biodegradable material (PUR-B) was mineralised of 9,73±1,95 %. According to the procedure described in the standard D 5988 our results were undervalued. Consequently absorbed CO2 released from biodegradeble materials was stabilised by reaction with BaCl2. The reaciton is needed to interpret the results correctly. A screening method for a quick test of biodegradability was designed. It included biodegradation by bacterial inoculum in mineral medium. The availability of materials for microbial degradation was meassured as a time-dependent function of optical density. The non-biodegradable residual particles of plastics represent a potential risk for the environment. The issue of microplastics and their quantification was..