Polypropylene components with improved mechanical properties through adjustment of the morphologies
Polypropylene is a commodity polymer that has not completely established a position in the laser-based powder bed fusion (PBF-LB/P) market since existing systems do not yet exploit the full potential of the polypropylene material. This is the starting point for the joint project’s objectives, which mainly include improving the mechanical performance of polypropylene components through targeted micro and macrostructure modification. As a result, nucleating agents are used to adjust the crystallization modification and spherulite size of the part. First, the crystallization behavior of specific selected nucleating agents is investigated under process conditions in the laboratory to ensure that the phases are stable under process boundary conditions. Next, the process investigations are conducted with selected systems, and the mechanical properties are analyzed. Using these results, the best modifications for Polypropylene in PBF-LB/P are determined. Furthermore, a general statement about the influence of the microstructure in PBF-LB/P is made. Since the entire process chain is represented beginning with synthesis the chemical structure of polypropylene is set via in situ synthesizing (heterophasic copolymers, terpolymer of propylene-1-butene-ethylene), and the mechanical compounding (ex situ) of various polypropylene with elastomeric contents is considered. This enables a thorough examination on the impact of the various approaches to incorporating the elastic components in the polypropylene matrix on the process. Similarly, the potential for a tailored material synthesis makes it possible to investigate various elastic components, enabling the system to be specifically tailored to the needs. Overall, it is possible to fully utilize the mechanical properties of this intricate material system, revealing new applications that call for ductile material behaviors.