Comparative analysis of the mechanical, thermal and barrier properties of polypropylene incorporated with CaCO 3 and nano CaCO 3

The primary advantages of polyolefins are that their properties can be improved through the use of additives. Polypropylene (PP) is a semi-crystalline polyolefin that has several advantages such as high strength, and low cost. However, it exerts some disadvantages, including a high molding shrinkage factor, poor mechanical properties, and low fracture toughness, which limit the widening of PP applications. This study investigates the influence of two types of fillers micro CaCO 3 and nano-CaCO 3 on PP composite mechanical, thermal, morphological and barrier properties and applications. The selected fillers were mixed at a different wt% with PP and compounded in a twin-screw extruder under 150 RPM and 180–200°C, and all specimens were rested for 24 h to dry before cutting and testing. All experimental results were analyzed by statistical arithmetic mean, the specimen micrographs revealed a good distribution of both fillers with a more visual pore throat shape in the PP/CaCO 3 composite structure. Where DMA test demonstrated that PP with CaCO 3 had reached the full rubbery zone earlier than PP with nano-CaCO 3 by 30ºC, reflecting that the incorporation of the nanofiller has revealed better thermomechanical property. Moreover, the nanofiller has increased the crystallization temperature for the composite by 14%, and the calculated permeability for all PP mixed with nano-CaCO 3 was reduced and averaged just above 7.0 g/m2x 24 h. Overall, the selected PP grade with low nanofiller content has demonstrated better enhancement to the PP nanocomposite general properties.