Improvement Of Flame Retardancy Of Polyaniline-and Polypyrrole-Deposited Conductive Paper Through Phytic Acid Doping

Doped with phytic acid (PA), polyaniline (PANI) and polypyrrole (PPy)-deposited conductive paper composites were prepared via in situ chemical polymerization process, and the effects of the doping conditions and oxidant on their conductivity and flame-retardant properties were also investigated in this paper. Some instrumental analysis methods such as SEM, XPS, and TGA were used to clarify the mechanism of the flame-retardant properties of the conductive papers.Both the conductivity and the flame retardancy of conductive paper were related to the amount of PANI/PPy deposited on the cellulose fibers. In the same condition, the higher amount of polyaniline/polypyrrole deposition, the great better of the conductivity and the flame retardancy of the paper.Doped with phytic acid, the effects of the dopant concentration, doping time, and doping temperature on the conductivity and the flame retardant properties of polyaniline-deposited conductive paper were also studied. When a concentration of0.3mol/L phytic acid was chosen as the doping acid, the optimum doping time and temperature were195min and0℃, respectively. The conductivity and the OI value of the optimal sample were2.25S/m and35.5%, respectively.Combined with previous experimental results, PANI coated conductive paper composites were prepared with sulfosalicylic acid and phytic acid, respectively. The experimental results show that the sulfosalicylic acid doped sample had a good electrical conductivity, while phytic acid doped sample had a better flame retardant performance. In a conclusion, using codoping acid to improve the overall performance of the PANI coated paper. The higher of the molar ratio of the phytic acid was, the better flame retardancy was. Conversely, the conductivity was decreasing. The comprehensive properties of the paper composite were excellent when the molar fraction of phytic acid was25%, both of the conductivity and the flame retardancy were at a better level.Doped with the phytic acid, the effect of the dopant concentration, doping time, doping temperature and oxidant conditions on the conductivity and the flame retardant properties of PPy-deposited conductive paper were studied. The optimal process of preparation of the polypyrrole-deposited conductive paper were also investigated. When a concentration of0.1mol/L phytic acid was chosen as the doping acid and0.075mol/L ammonium persulfate as oxidant, the optimum doping time and temperature were2h and0℃, respectively. The conductivity and the OI value of the optimal sample were12.54S/m and27.80%, respectively.The properties of PANI-and PPy-deposited conductive papers were compared. It was found that PANI-deposited paper performed better for the flame retardant effect and the tensile strength; While, the environmental stability and the conductivity of PPy-deposited paper was better than that of PANI-deposited paper.The results of SEM showed that PANI-deposited conductive paper doped with phytic acid had a good morphology of the PANI composites. And the residue of the PANI-deposited conductive paper after burning kept the fiber morphology, and some microparticles were observed. The results of XPS showed that after combustion the polyaniline and parts of the fiber of the residue became carbonized. And the amount of combustion residue of the PANI coated paper was higher than the amount of PANI deposition on the fibers which indicated that the carbonized PANI protected the fiber from burning in the process of combustion. The results of TGA further confirmed the effect of doping acid on the flame-retardancy of PANI-deposited conductive paper and theoretically gave the reason why phytic acid doped sample had a better flame retardant performance.