Bachelor’s Thesis or Master’s Thesis
© pixabay.comTopic of the Thesis
Plastic packaging is largely made from polyolefins. These account for nearly two-thirds of all post-consumer plastic waste. The most common types of polyolefins are polyethylene (PE) and polypropylene (PP). Current sorting technologies cannot guarantee complete separation of PP and PE, so cross-contamination must be expected. In Germany, a distinction is currently made between a flexible PE-LD fraction and the
dimensionally stable PE-HD fractions, PP fractions, and various blended polyolefin fractions. Quality assurance for processed plastic waste—known as recyclates—is necessary, among other reasons, because contamination of PE with PP (or vice versa) affects plastic processing methods (e.g., film extrusion) and impairs the performance of the final product. Knowledge of the composition is therefore crucial for ensuring the quality of the recyclate. One method for assessing recyclate quality is the relative comparison of melt enthalpies using DSC.
The paper is being written in this working group
The tests conducted in the physical laboratory of the Center for Plastics Analysis and Testing (KAP) provide significant support to both industry and the institute’s own research in validating manufacturing parameters. Another focus is on material characterization through thermal, spectroscopic, rheological, and chromatographic analyses to evaluate material behavior and thus address not only research questions but also industrial challenges. Through these analyses, the laboratory provides essential insights for optimizing production processes and improving component quality. This also includes the analysis of recycled materials and gaining a deeper understanding of their composition.
Objective
The goal of this thesis (bachelor’s or master’s thesis) is to adapt the evaluation routine developed for determining PE/PP fractions in defined mixtures to polyolefin recyclates of unknown composition. To this end, an evaluation method will be developed. The thesis begins with a literature review on potential challenges in the thermal analysis of unknown polymer blends and current approaches to characterizing PE/PP fractions. The focus of the thesis is on the analysis of recycled materials (e.g., differences in crystallization, additives). Recyclates of unknown composition and virgin material blends of known composition, as well as corresponding DSC measurement results, are available for the development of the evaluation routine (e.g., calibration curves). In addition, specific further blends and recycled materials are to be examined in order to validate the developed evaluation routine. For this bachelor’s thesis, the initial focus is on characterizing the virgin material blends and developing an automated evaluation method for determining the respective polymer fractions in each blend system. As part of a master’s thesis, recycled materials of unknown concentration will also be evaluated for their foreign polymer content based on calibration systems to be developed within this thesis. Furthermore, the automated analysis must be validated with regard to the possible presence of other foreign polymers (e.g., PET, PS, etc.) and optimized as needed.
Your Assignment
- Literature Review and Methodology Development
- Sample Preparation
- Training in the operation of a DSC and the interpretation of results
- Evaluation and classification of the generated results
Your Profile
- A degree in engineering or the natural sciences (e.g., mechanical engineering, industrial engineering, materials science…)
- Interest in analytical tasks and hands-on work in the lab
- An independent, structured, and team-oriented approach to work
Here are your benefits
- Work in a motivated team
- Independent work with support tailored to your needs
- Working on research-related questions
- Individual coordination of tasks and timelines
- Experimental work with laboratory equipment
- Short-notice start possible / quick turnaround without delays
If you’re interested in this assignment, please feel free to contact us. We’ll work with you individually to determine the exact scope and timeline.