Preparation, Characteristic, Structure And Applied Research On Polyphosphoric Acid Doped Polyaniline

This paper conducts a research on producing doping polyaniline by Chemical Oxidation and explores the influence of factors on doped polyaniline yield, doping ratio and electric conductivity by by employing orthogonal test-schem, and characterizes its structures. By testing oxygen index and smoke density by blending poly phosphoric acid doped polyaniline produced in optimized condition and low density polyethylene, the author further discusses its flame retardant property. The main contents are listed as follows.With polyphosphoric acid as the doping acid and aniline as monomer, ammonium persulfate as oxidizing agent, Poly phosphoric acid doped polyaniline are produced by Oxidative polymerization. L25(5)6orthogonal experimental table are designed to optimize experimental conditions such as temperature factor, the added dropwise time factor, the reaction time factor, the amount of oxidant factor, the amount of polyphosphoric acid and Polymer initial phosphate concentration factors. By applying Quinoline phosphomolybdic acid precipitation to analyze the phosphorus in doped polyaniline, the author finds out that the optimum conditions are:temperature of15℃, less than60-min dropping time,6-hour reaction time, ammonium persulfate and aniline’s substance ratio is1:1, the polyphosphoric acid and aniline’s substance ratio is between1:2.0and1:2.5, the initial concentration of polyphosphoric acid is1.5mol·L-1.By employing fourier transform infrared, scanning electron microscopy, TEM (transmission electron microscopy), the author analyze and characterize doped polyaniline made in optimum conditions, whose results show that the polyphosphoric acid can be used as the protonic acid dope into polyaniline, doped polyaniline structure presents as nano-fibrous with good thermal stability.By blending fire retardants such as poly phosphoric acid doped polyaniline, vinyl acetate, bentonite clay, talcum powder, pentaerythritol and so on with polyethylene in low density, by applying national standard method to text the oxygen index and smoke density and mechanical properties, and by optimizing formula with orthogonal experimental design method, the author expounds the flame retardant properties of polyaniline and ultimately gets the oxygen index is25.6and low density polyethylene with good mechanical properties of low smoke density, halogen-free and good flame-retardant effect,and also analyzes it with SEM and TGA characterization.