Electrical Properties and Thermo-Oxygen Stability of Polypropylene Modified by Polydopamine

In this paper, a modification method using polydopamine (PDA) to modulate the properties of polypropylene (PP) is presented. PDA was synthesized, and PP composites with PDA additions of 0.1 wt.%, 0.3 wt.%, and 0.5 wt.% were prepared by melt blending method. The PP was characterized by Fourier Infrared Spectrometer (FIR). The properties of PP samples were analyzed by a series of methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), DC breakdown test, broadband impedance test, and oxidation-induced period test (OIT). The results showed that the introduction of PDA into PP promoted the generation of β-crystals. The composites exhibited a significant enhancement in electrical properties and thermo-oxidative stability compared to unmodified PP samples. 0.3 wt.% PDA-PP showed the best breakdown performance, with the characteristic breakdown field strength increasing by 25.1 kV/mm compared to pure PP. The OIT value increased with the rising amount of PDA added, and the OIT value of 0.5 wt.% PDA-PP was prolonged by 17.1 min relative to pure PP.