Ba, Ma, Ph.D and jobs

Offers for student assistants

We are often looking for student assistants (SHKs), but at irregular intervals ….

You are welcome to ask at any time without commitment:

Dr. Werner Pauer

Room: TMC B 218

Phone: +49 40 42838-6007

e-mail: werner.pauer@uni-hamburg.de(pauer"AT"chemie.uni-hamburg.de)

Internships, bachelor, master and doctoral positions

Also in the future, beyond 2022, topics for all kinds of internships, bachelor or master theses or doctoral projects are available. Please contact:

Dr. Werner Pauer

Room: TMC B 218

Phone: +49 40 42838-6007

e-mail: werner.pauer@uni-hamburg.de(pauer"AT"chemie.uni-hamburg.de)

Acoustic levitation - investigation of multi-component mixtures in single drops

Transfer of a ring-opening polymerization of ε-caprolactone to spray polymerization in a spray tower

3d printed tools for Injection Moulding of Rubber Compounds

Contact person: Alexey Stepanyuk, Jens Chen, Werner Pauer
E-mail: Alexey.Stepanyuk"AT"uni-hamburg.de, i-chieh.chen"AT"uni-hamburg.de, werner.pauer"AT"uni-hamburg.de

Room: TMC A202 or B218
Phone: 040 42838 - 6003 or -6007
Duration: 4-6 weeks
Interpretation: Research internship in a Bachelor-/ Masterthesis
General description:

Injection molding of rubber compounds is a widely used technology in the manufacture of rubber and plastic products. The tools used in this process must be very precise to ensure the desired product quality and accuracy. However, manufacturing tools using traditional manufacturing methods such as CNC machining is very expensive and time consuming. 3D printing technology offers a promising alternative here, as it can produce prototypes and small series quickly and inexpensively.
The aim of this master thesis is to investigate the feasibility and suitability of 3D printed tools for the injection molding of rubber compounds.
The study is carried out in three steps. In the first step, different 3D printing technologies and materials are identified and evaluated. For this purpose, the advantages and disadvantages of each technology and each material as well as their suitability for the injection molding of rubber compounds are examined. In the second step, various 3D printed tool designs are created and manufactured. These tools are then evaluated using various tests such as dimensional accuracy, surface roughness and material compatibility. In the third step, the results from the first two steps are compared and evaluated to assess the advantages and disadvantages of 3D printed tools compared to traditional tools.

The results of this study will show whether 3D printed tools are suitable for the injection molding of rubber compounds. It is expected that 3D printed tools can be manufactured quickly and cheaply, and have comparable quality and accuracy to traditional tools. The conclusions of this study can help to promote the use of 3D printing technology in tooling for rubber compound injection molding and enable the development of new tooling designs.

Experimental implementation of a scale up for emulsion copolymerisations using 3D-printed stirring elements

Calorimetric studies of miscellaneous initiators and initiator systems for the synthesis of polymers

Determination of the temperature dependence of the Dushman reaction in highly viscous systems

Functionalization of a 3d printed surface

3D printed continuous reactors for emulsion polymerization and fiber optic temperature measurement

Investigation of the influence of macro and micro mixing quality on the propoxylation of polypropylene glycol using DMC catalysis in a loop reactor

Contact person: Andres Castro Villavicencio/Werner Pauer
E-Mail: andres.castro@uni-hamburg.de(wladislaw.dolshanskiy"AT"uni-hamburg.de) , werner.pauer"AT"uni-hamburg.de

Room: TMC C224 or B218
Tel.: 040 42838 -6054 oder -6007
Duration: 4-6 weeks
Designed for: Research internship in a Bachelor-/ Masterthesis, Promotion

- Investigate macromixing at the loop reactor
o Design and printing of clear Kenics mixing elements in the loop reactor
o Catalyst in PPG with PIV and dye injection with PLIF (RT)
- Micromixing on the 2L autoclave reactor
o VD response for micromix quality at injection point (RT) at different viscosities and different flow rates on the 2L autoclave reactor
o Comparison of two injection methods
o Residence time measurement with impact marking
- Reaction at the 2L autoclave reactor with knowledge gained from different injections

Propoxylation of Polypropylene Glycol (PPG) is an important process in the manufacture of polyurethanes, lubricants and other chemicals. The use of double metal cyanide (DMC) catalysts in a loop reactor enables efficient and cost-effective production of PPG. The mixing quality is an important factor for the effectiveness and efficiency of the process and the final product properties. Macro and micro mixing quality can be influenced by various methods, e.g. by using Kenics mixing elements or by varying flow rates and injection methods.
The aim of this project is to investigate the influence of macro and micro mixing quality on the propoxylation of PPG by DMC catalysis in a loop reactor. By systematically varying the mixing conditions, optimal conditions for an efficient and cost-effective production of PPG are to be determined. The loop reactor will be equipped with a mixer, which will be manufactured using the mSLA 3D printing process and made completely transparent so that Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) can be used inside.
The project comprises two sub-areas: macro-mixing on the 3D printed loop reactor and micro-mixing on the 2L stainless steel autoclave reactor using the Villermaux-Dushman reaction. In both sub-areas, the mixing conditions are varied systematically, e.g. by using Kenics mixing elements, varying flow rates and injection methods. PIV and PLIF are used to analyze the mixing quality in the loop reactor. The mixer in the loop reactor is made using the mSLA 3D printing process and made completely transparent so that you can work with PIV and PLIF inside.
Summary: This project aims to investigate the influence of macro and micro mixing quality on the propoxylation of PPG by DMC catalysis in a loop reactor. By systematically varying the mixing conditions, optimal conditions for an efficient and cost-effective production of PPG are to be determined. The use of a mSLA 3D printed transparent mixer enables real-time visualization and analysis of the mixing dynamics, thus contributing to a deeper understanding of the mixing conditions and process optimization.