Sulfonation of chlorinated polypropylene and its influence on the microstructure and the electric properties of polypropylene/chlorinated polypropylene/polyaniline composites

Abstract

Sulfonated CPP (CPP-SO 3H) was prepared by modifying chlorinated polypropylene (CPP). The results of Fourier transform infrared spectroscopy (FTIR) illustrate that the sulfonic acid group (-SO 3H) was successfully grafted onto CPP. Polypropylene (PP)/CPP-SO 3H/ polyaniline (PANI) and PP/CPP/PANI composites were prepared, and the microstructures and electric properties of the corresponding composites were carefully investigated by scanning electron microscopy (SEM), FTIR, ultraviolet (UV)-vis and wide-angle X-ray diffraction (WAXD). Compared with that of the PP/CPP/PANI composite, the volume resistivity of the PP/CPP-SO 3H/PANI composites is lower. The UV-vis results show that PANI can be doped with CPP-SO 3H and that the interactional strength between PANI and CPP-SO 3H increases because of the introduction of -SO 3H. The results of WAXD show that CPP-SO 3H is more easily inserted into the interspaces of PANI-dodecylbenzene sulfonic acid and makes the layer distance increase compared with that of CPP. The addition of CPP-SO 3H can improve the crystallinity of the composites. The results of SEM show that the introduction of -SO 3H on CPP is favorable for dispersion of PANI in the PP/CPP-SO 3H/PANI composites, and that it results in an increase in the area of the conducting components, an improvement in conductive properties and the compatibility of the PP/CPP-SO 3H/PANI composites. The above results indicate that CPP-SO 3H can act as PANI's doping agent and facilitate compatibility in PP/CPP-SO 3H/PANI composites. © 2012 The Society of Polymer Science, Japan (SPSJ) All rights reserved.