Characterization of post-use Polyethylene and Polypropylene Recyclate Blends for Pipe Applications
Sprache des Titels:
Proceedings of the 19th Plastic Pipes Conference PPXIX
In the present work two rPE and two rPP grades originating from post-use sources such as bottle caps, extrusion blow molded objects and injection molded items were analyzed together with six PE-PP recyclate blends produced from these four base recyclates. The recyclate blends differed in the rPE-to-rPP ratio and the amount of calcium carbonate additive used in the recyclate compounding and blending step.
Composition and molecular characteristics of both post-use base recyclates and recyclate blends were investigated using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). A subsequent mechanical characterization based on concepts of linear-elastic fracture mechanics was performed using compact-type (CT) specimens to determine the crack growth resistance of the various recyclate materials under cyclic loads.
Small amounts of legacy substances were detected in both rPE and rPP. In terms of crack growth resistance, clear rankings of the materials were derived, with the recyclate blends being inferior to the neat rPE or rPP materials.