Improved electrical, mechanical and EMI shielding properties of PANI-VGCF-DBSA/DVB hybrid nanocomposite

A Polyaniline (PANI) based electrically conductive thermosetting hybrid nano-composite has been prepared by incorporating high apparent-density type vapor grown carbon fibers (VGCF-H) as additional conductive filler. The main conducting component of the matrix is PANI, protonated with a protonic acid, dodecylbenzenesulfonic acid (DBSA). Divinylbenzene (DVB) is used as a cross-linked thermosetting polymer. With addition of VGCF-H higher electrical conductivity and better mechanical properties have been achieved. Different weight percentages of VGCF-H in the PANI-DBSA/DVB matrix, were used and their effect on composite's properties have been investigated. Electrical conductivity up to 1.97 S/cm with the addition of 5 wt. % VGCF-H and flexural modulus of 1.71 GPa with 3 wt. % of VGCF-H have been achieved. Electromagnetic interference (EMI) shielding properties of composite with and without VGCF-H are measured in X-band frequencies and compared. Composite with 5 wt. % VGCF-H has shown EMI shielding effectiveness about 51 dB in X-band, which is higher than the composite without VGCF-H (around 22 dB). The morphologies of the composites were studied by SEM analysis. The effect of dispersion on electrical and mechanical properties also has been explained using SEM micrographs. The results of these studies confirmed that a polymer thermoset conductive composite with improved electrical, mechanical and EMI shielding effectiveness has been successfully prepared.