Study On The Preparation And Property Of PP/NR/Nano-CaCO₃ Ternary Composite

In this paper, the PP/Nano-CaCO₃ binary composite and PP/NR/Nano-CaCO₃ ternary composite material were prepared and studied by the method of melt blending. Meanwhile, the influence of the amount of Nano-CaCO₃ and NR was discussed on the mechanical properties, rheological properties, crystallinity and thermal stability of PP. Lastly, the dispersion of Nano-CaCO₃ in PP and micro morphology structure of the PP/NR/Nano-CaCO₃ ternary composite material were observed. At the same time, the influence of different processing methods of PP/NR/Nano-CaCO₃ ternary composite material was discussed on rheological properties and mechanical properties. The results showed that: with the increasing content of Nano-CaCO₃, the tensile strength, flexural strength, flexural modulus and impact strength of the PP/Nano-CaCO₃ binary composite were first increasing and then decreasing, and the elongation at break monotonically decreased. The tensile strength, flexural strength, flexural modulus and impact strength of the PP/Nano-CaCO₃ binary composite respectively reached the maximum value?23.4 MPa, 40.3 MPa, 1355.7 MPa and 46.5 k J/m2? when the content of Nano-CaCO₃ was 10 wt%, the corresponding elongation at break was 827.1%; with the increasing content of NR, the tensile strength, flexural strength and flexural modulus of the PP/NR/Nano-CaCO₃ ternary composite material gradually decreased, the elongation at break and impact strength gradually increases. When the NR content was 6wt%, the tensile strength, elongation, flexural strength, flexural modulus and impact strength of the PP/NR/Nano-CaCO₃ ternary composite material were respectively 21.9 MPa, 915.2%, 37.4 MPa, 1147.4 MPa and 48.6 k J/m2; with the increasing content of Nano-CaCO₃, the equilibrium torque gradually increased and the processing performance reduced under the same temperature and shearing rate. Loading NR and Nano-CaCO₃ respectively made the equilibrium torque of PP decrease and increase, while the equilibrium torque of the PP/NR/Nano-CaCO₃ ternary composite material was improved by the synergistic effect; Nano-CaCO₃ makes spherulite radius of PP smaller and multiple by POM and XRD. With the increasing content of MAPP, the tensile strength of the PP/Nano-CaCO₃ binary composite first increased and then tended to be stable, the variation of elongation at break was not obvious, the flexural strength and flexural modulus gradually increased, and the impact strength first increased and then decreased. When the content of MAPP was 6 wt%, the tensile strength, elongation at break, the flexural strength, flexural modulus and impact strength were respectively 25.2 MPa, 832.9% and 41.6 MPa, 1377.1 MPa and 47.8 k J/m2; By DSC and TGA, the Nano-CaCO₃ can improve the thermal stability of PP and has little effect on the rate of weight loss, but NR reduced the thermal stability of PP and improved the decomposition rate of the system; By SEM, PP filled with the 10 wt% Nano-CaCO₃ material had no reunion phenomenon of Nano-CaCO₃ and evenly dispersed, but the fracture section of PP/Nano-CaCO₃ composite with NR which appeared obvious ups and downs, filamentous shapes and toughening features showed the toughness enhancement; Finally the effect of the composites of the different preparation methods on mechanical properties and rheological properties showed that the tensile strength, elongation at break, flexural strength, flexural modulus and impact strength of the composite materials with core-shell coating were better than the corresponding mechanical properties of direct blending preparation; contrary to the core-shell coating method, the equilibrium torque of direct blending preparation was slightly higher.