Conducting filler based on chitosan and grafted polyaniline (Ch-g-PANI) was prepared with different grafting ratios and used as fillers for polyester powder coating system. Differential scanning calorimetry is applied to study the effect of Ch-g-PANI on the curing of the polyester powder coating. The activation energy calculated by isoconversional Kissinger method was increased by either increasing the Ch-g-PANI content or the content of polyaniline in the filler, suggesting the contribution of the filler in the curing reactions. The cured samples were characterized using FTIR and TG analyses. Thermogravimetric analysis showed that the total thermal stability was enhanced upon the filler addition as detected from the values of integral procedural decomposition temperature. Furthermore, a dielectric study showed that the dielectric constant and loss were increased upon increasing of the filler. Vogel-Fulcher-Tammann equation was well-fitted when used to examine the dependence of alpha-relaxation on the temperature and the dielectrically calculated T-g values were comparable to that measured by DSC. The shielding effectiveness toward microwaves was enhanced by increasing the filler content. POLYM. ENG. SCI., 59:372-381, 2019. (c) 2018 Society of Plastics Engineers