Manufacture and Comparison of Mechanical Properties of Reinforced Polypropylene Nanocomposite with Carbon Fibers and Calcium Carbonate Nanoparticles

In current research, in order to manufacture reinforced polypropylene composite with carbon fibers and CaCO3 nano-particles, polypropylene granules were fed to an extruder with specific percentages of maleic anhydride compatibilizer and calcium carbonate nano-particles and then extruded compound granules were hot-pressed inside a mold. After generating resin sheets from these granules, they were sandwiched between carbon fiber plain fabrics and heat-pressed, consequently samples of nano-composite are prepared. Standard mechanical tests of tensile, bending and impact were performed on prepared samples of both types of reinforced polypropylene composite with carbon fibers containing nano-particles and without nano-particles. Results showed that composite specimens containing calcium carbonate nano-particles endure 87% more tensile strength, 26% more bending strength and 40% more impact strength than specimens without nano-particles. The maleic anhydride compatibilizer, due to formation of polypropylene-calcium carbonate co-polymer, improves the uniformity of the compound and increases adhesion between polypropylene and calcium carbonate phases. Because of higher elasticity modulus of nano-particle compared to the polypropylene matrix as well as the possible nucleation of nano-particles in the polymer matrix, the overall strength of the nano-composite sample has increased. Also due to the symmetric shape of the quasi-spherical calcium carbonate nano-particles, these particles have isotropic properties in different directions and lead to an increase in the level of crystallinity in the polymeric matrix and the strength of the nano-composite. The dispersion of nano-particles in the polypropylene base causes the impact energy to be spread across the whole cross-section and thus the energy absorption capacity increases before fracture