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Interfaces between polymer/ceramics have wide application in mechanical, electronic, and chemical engineering. For example, polypropylene (PP) is usually used as a separation between electrodes in batteries, and silicon oxide (SiO₂)is sometimes added on PP to improve the separation's properties; the interface properties between PP and SiO₂ determine the improving effect directly. Specifically, some parts (e. g. batteries) often service in a higher temperature above the room temperature due to various heat management problems and specific application environment, thus temperature-dependent interface properties attract much attention.

In this work, the interface intrinsic strength and fracture energy of PP/SiO₂ are firstly studied based on molecular dynamic tensile method at 1 K. Furthermore, the temperature effect on the interface properties is studied by increasing temperature to 100 K, 200 K, 300 K and 400 K, respectively. Interface damage is characterized quantitatively based on the interface free volume and the deformation of PP single chains. And the mechanism of temperature dependence is discovered combining with the damage characterization.

The results show that the interface strength of PP/SiO₂ is 0.257 GPa at the atomic scale at 1 K at tensile speed of 10 m/s, and the intrinsic fracture energy is 0.068 J/m². As the tensile temperature increases, both the interface strength and fracture energy decrease. At the room temperature, the interface strength is 0.151 GPa, and the intrinsic fracture energy is 0.063 J/m². When the temperature is higher than the glass transition temperature 267 K of PP, the interface fracture behavior changes from a catastrophic fracture to a continuous fracture. The mechanism is related to the change of the damage. When the temperature rises from 1 K to 400 K, the interfacial free volume of PP increases by 11.6 times, and the increment of average gyration radius of all PP single chains increases by 6.6 times.

computation, modeling, simulation, interface damage