Title awarding university: Leibniz University Hannover

Title of the doctoral project: Classification and prediction of material properties and degradation in the mechanical recycling process of polyolefins using near-infrared spectroscopy (NIRS)

Short description of the doctoral project: Despite the widespread use of near-infrared spectroscopy (NIRS) in the field of plastics recycling, the method is predominantly only used to identify polymers in the sorting process based on the spectroscopic fingerprint. However, various studies have shown that, in addition to the pure classification of polymers, properties can also be predicted and subgroups identified. The previous investigations show potential based on individual tests on various polymers, but do not provide a complete overview of the possibilities of the method in the context of recycling polyolefins.

As part of this doctorate, spectroscopic data from polyolefins will be systematically analysed using various machine learning methods in order to explore the limits and potential of the method for the recycling of polyolefins. The aim of the doctorate is, on the one hand, to increase the information yield in the offline analysis of polyolefins and, on the other hand, to gain information on degradation through inline measurement in the extrusion process. This information is to be utilised in a measurement control loop in order to increase quality.