Preparation And Properties Research Of Conductive Polymer Composites

Conductive polymer have become one of the most widely used materials due to their easy processability,good environmental stability,excellent electrical conductivity and inherent flame retardancy.However,materials with a single performance have been unable to meet the needs of social development.Thus,conductive polymer composites with various excellent properties after doping have emerged.The polypyrrole(PPy)and polyaniline(PANI)are popular materials among conductive polymer materials because of their excellent electrical conductivity and flame retardant properties.In this paper,PPy/reduced graphene oxide(RGO)composite electrode materials and PANI/montmorillonite(MMT)/polystyrene(PS)flame retardant nanocomposites were prepared and investigated,respectively.Their surface topography,internal structure,electrochemical performance and flame retardancy tests were aslo performed.The main conclusions were summarized as follows:The PPy/RGO nanocomposites can be prepared by a very simple one-step in situ synthesis polymerization without further reduction of GO/PPy nanocomposites.On the one hand,1,4-p-benzoquinone is used as an oxidizing agent for PPy in the preparation of RGO/PPy nanocomposites.On the other hand,its reduced product,hydroquinone,acts as a reducing agent for GO.In addition,the 1,4-benzoquinone can also be used as redox-active media which can provide pseudo-capacitance.In this experiment,different proportions of nanocomposite electrode materials GP1,GP3,GP5(GO:pyrrole=10/90,30/70,50/50(wt%/wt%))were prepared.A three-dimensional urchin-like physically crosslinked porous microstructure composed of two-dimensional RGO sheets and one-dimensional PPy has been formed in GP3 and GP5,which contributes to the transport of electrolyte ions.Compared with the pristine GO and PPy s the electrochemical properties of composites GP1,GP3,GP5,including specific capacitance(5 F g-1?100 F g-1 for GO and PPy,respectively)and potential window are significantly improved.Their specific capacitances are increased to 343 F g-I,454 F g-1 and 435 F g-1,the potential windows are broadened from 1.0 V to 1.2 V,1.6 V and 1.8 V,respectively.Symmetrical supercapacitors assembled from GP3/GP5 nanocomposite electrode materials exhibit good supercapacitance behavior,and their energy densities were up to 50.0 Wh kg-1 and 49.2 Wh kg-1 under the same power density of 0.75 kW kg-1,respectively.GP3(54%capacitance retention ratio)and GP5(65%capacitance retention ratio)provided good cycle stability after 10,000 cycles.PANI/MMT/PS flame retardant nanocomposites modified by sodium dodecyl benzene sulphonate(DBSNa)and 1,5-naphathalene disulfonic acid(1,5-NDA)were synthesized by a facile in situ polymerization.The result provided that introduction of DBSNa and 1,5-NDA can induce the ordered growth of PANI and the exfoliation of MMT layer,and the prepared modified nanocomposites are named as DPM and NPM,respectively.The modified nanocomposites were used as flame retardants for PS,and different ratios(MMT/DPM/NPM loadings 1 wt%,3 wt%,5 wt%,respectively)of PS/MMT,PS/DPM,PS/NPM flame retardant nanocomposites were prepared by melt blending.The agglomeration of MMT layer with the stacked layered structure in the nanocomposite was reduced,and the surface morphology was relatively loose.The result provided that the introduction of DPM and NPM can significantly improve the thermal stability of PS,and its flame retardant and smoke suppression performance was also significantly enhanced.Compared with pure PS,the peak of heat release rate(PHRR)of PS/NPM3(3 wt%of NPM)and PS/NPM5(5 wt%of NPM)was reduced by about 50%,and the peak of CO release rate(PCORR)was reduced by about 40%,showing excellent flame retardant and smoke suppression effects.Compared with MMT and DPM,NPM can provide the best flame retardant and smoke suppressing effect,which is mainly due to the three-dimensional network structure formed by the exfoliated MMT layer and the PANI chain uniformly dispersed in the PS matrix.