Polypropylene (PP) composites that contain poly(aniline) (PANI) and ammonium polyphosphate crystalline form II (APP‐II) have both antistatic and flame‐retardant properties. In the present study, double anti‐functional PANI was prepared via in situ polymerization in the presence of APP‐II. Analysis of the Fourier transform infrared spectra demonstrated that PANI was synthesized successfully with APP‐II and that modified PANI (PANI‐APP) was obtained. Next, PP/PANI‐APP/chlorinated poly(propylene) (CPP) and PP/PANI/CPP composites were prepared. The results showed that the volume resistivity of the PP/PANI‐APP/CPP composite was at least 100 times less than that of the PP/PANI/CPP composite. The microstructures of the corresponding composites were investigated carefully by scanning electron microscopy and wide angle X‐ray diffraction. The areas of the conductive regions and the percentage crystallinity of PP in the PP/PANI‐APP/CPP composite were distinctly higher than those in the PP/PANI/CPP composite, i.e., by about 10% and 7%, respectively. In addition, experimental analyses of the limiting oxygen index and thermogravimetry showed that the PP/PANI‐APP/CPP composite had advantages compared with PP in terms of its flame‐retardant properties thermal stability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40732.