Modification of compressive characteristics in 3D printed polyolefin elastomers/polypropylene blend structures through polypropylene content and infill density adjustment

In this research, 3D printed Polyolefin Elastomers (POE)/Polypropylene (PP) blends with varying PP concentrations were prepared and characterized for compressive and energy absorption applications. To achieve this, POE/PP blends with 10%, 30%, and 50% PP concentrations were created. Cubic energy absorption samples with a honeycomb pattern and two different infill densities were printed using a Fused Granule Fabrication (FGF) printer to examine the influence of infill density and blend composition on compressive properties. The blends were analyzed using Scanning Electron Microscopy (SEM), Dynamic Mechanical Thermal Analysis (DMTA), tensile, and compression tests to study their printability, morphological, thermal, and mechanical properties. SEM results showed that the samples had two distinct phases with a sea-island pattern, which changed to co-continuous and less miscible in the 50% PP concentration blend. Additionally, good printability without defects was observed in the blends. DMTA demonstrated that the melting point of the samples increased with higher PP content, while miscibility decreased. Tensile tests revealed great elasticity, with strain values ranging from 1204 to 1646% for all samples. Furthermore, tensile Young’s modulus, Ultimate Tensile Strength (UTS), and toughness increased with increasing PP content, while elongation decreased. Compression tests indicated that increasing PP content enhanced energy absorption and compressive properties. Moreover, higher infill density led to earlier densification and improved energy absorption and compressive properties.

Graphical abstract