Micro and nanoparticulate PP/CaCO3 composites mechanical, thermal and transport properties - DOE

Abstract

Abstract Composite based on PP/CaCO3 contained micro and nanoparticles were investigated in relation its activation volume, mechanical, thermal and transport properties. The additives were initially dispersed in homopolymer polypropylene (hPP) blended with compatibilizer maleic anhydride grafted polypropylene (PP-g-MA) in twin-screw extruder, producing CaCO3 masterbatches, that were subsequently diluted in hPP. To optimize fillers dispersion in the polymer matrix, a Design of Experiment (DOE) was used, that combined Extruder screw rotation (N: 250 and 500 rpm); Extruder feed flow (Q:10 and 15 kg/h) and Average particle size (ϕ: 40 nm and 1.7 μm) at four different filler concentrations. Based on mechanical characterization results, the best process found was 500 rpm@10 kg/h, which provided suitable Specific Mechanical Energy (SME), increasing the nanocomposites strength. Finally, improvements of Impact Resistance up to 7.8% and Young's Modulus up to 9.3% related to microcomposite and Tensile Strength (Fmax), up to 7.9%, related to hPP, with higher strain.

Keywords

• activation volume
• calcium carbonate
• design of experiment
• mineral fillers
• nanocomposites