聚丙烯/导热填料复合材料的制备及性能和界面作用

Polypropylene (PP) was modified with single-component filler and multi-component filler with different dimensions, including zero-dimensional spherical materials such as aluminum nitride and copper powder, one-dimensional linear materials like carbon fiber powder and carbon powder, as well as two-dimensional flaky graphite, and evaluated for the tensile strength, flexural modulus, heat deflection temperature and thermal conductivity. The structural model of the composites obtained was constructed by Materials Studio software, with molecular dynamics simulations carried out to calculate the shear modulus and interfacial interaction parameters (binding energy, mean square displacement, diffusion coefficient). The results showed that, the ternary-component filler (graphite-carbon fiber powder-aluminum nitride) modification significantly improved the thermal conductivity of PP to 0.326 W/(m·K), an increase of 74.3% compared with PP, and increased the heat deflection temperature of PP to 118.2 ℃, an increase of 34.6% compared with PP, while maintaining good mechanical properties, with a tensile strength and flexural modulus of 38.6 MPa and 2686 MPa, representing increases of 8.7% and 73.7% over PP, respectively. The shear modulus calculated through molecular dynamics simulation was basically consistent with the flexural modulus tested by experiments, and the binding energy, mean square displacement, diffusion coefficient showed the same trend.