Building a Novel Chemically Modified Polyaniline/Thermally Reduced Graphene Oxide Hybrid through π-π Interaction for Fabricating Acrylic Resin Elastomer-Based Composites with Enhanced Dielectric Property.

Sustainability urgently demands low dielectric loss and low elastic modulus as fostering high permittivity (Hi-K) conductor/polymer composites. This work introduces a ternary composite system, consisting of acrylic resin elastomer (AR), chemically modified polyaniline (HBSiPA), and the thermally reduced graphene oxides (TrGOs), for applying to actuators, of which AR was fabricated by free radical polymerization. The unique hybridized graphene (HBSiPA-TrGO) was prepared by a two-step procedure, including the doped polyaniline modified by the hyperbranched polysiloxane via a ring opening reaction, followed by the decoration of HBSiPA on the surface of TrGO, the conductivity of which is desired to be the same as that of graphene. Afterward, diverse filler contents of HBSiPA-TrGO were put into the AR matrix to fabricate composites with the solution casting method and TrGO/AR composites were fabricated as well for comparison. Unlike TrGO, HBSiPA has plenty of polyaniline chain segments that ensure better dispersion of graphene hybrids in the AR, and thus the composites inherit the excellent electrical property of graphene. The permittivity and dielectric loss of the HBSiPA-TrGO/AR composite at 100 Hz are 3.5 and 0.27 times that of the TrGO/AR composite, respectively, when the loading of fillers approaches the percolation threshold (fc), which originates from the HBSiPA anchored onto the graphene serving as spacer and thus decreases the leakage currents induced by the contact of graphene sheets. Besides, the elastic modulus of 2.83 vol % HBSiPA-TrGO/AR composite was lower than 5 MPa.