Development And Characterize Of Functional Polypyrrole Composites

Polypyrrole(PPy)is a category of typical intrinsically conducting polymers(ICPs).Recently,it has gained much attention for its numerous advantages such as tunable electrical/dielectric properties,good environmental stability,low density and simple development.However,PPy developed from chemical polymerization exhibits poor mechanical properties and low electrical conductivity,thus lead to a limited application.Polydopamine(PDA)is a kind of marine biomimetic materials inspired by the marine mussel.It is generally known that one of the most striking properties provided by PDA is incredible adhesion ability.Under alkaline conditions,DA has been found to self-polymerize to form PDA film on almost all surfaces,include metal,rock and polymer.PDA has usually been used in surface modification of materials.Act as the one-dimensional(1D)form of silver,Ag nano wire(AgNW)contains many unique properties including salt spray corrosion durability,high stretchability and the features of nanophase materials.Moreover,the very high aspect ratio of AgNW making it a promising conductive filler.The thesis prepared PPy/PDA/AgNW composites via a simple chemical in situ polymerization followed by mixture process.Research is as follow.(1)PPy/PDA composites were prepared via a chemical polymerization in alkaline condition.After being characterized by SEM,FTIR,Raman and four points probe,et al.,it proves that the morphological features of composite are different from pure PPy,and there is strong binding force between PPy and PDA.In addition,the electrical conductivity of the composes changes with the ratio of reagents.When the mole ration of DA/Py is 0.09,the maximum value is 0.01 S/cm.(2)PPy/PDA/AgNW composites were developed by mixture process.A possible structure of the composite has been inferenced after being characterized by FTIR and Raman.Thermal data demonstrate that thermal stability of pure PPy strengthens significantly after being reinforced with PDA and AgNW.On the other hand,after being incorporated with AgNW,the conductivity increases from 0.01 S/cm for PPy/PDA to 1206.72 S/cm for PPy/PDA/AgNW(50 wt.%),a leap from 0.11 S/cm for PPy/PDA/AgNW(16 wt.%)to 54.77 S/cm for PPy/PDA/AgNW(20 wt.%)is noted.The PPy/PDA/AgNW(50 wt.%)composites exhibit high EMI SE of 48.4 dB at 8.0 GHz but show superior lightweight of 0.332 g/cm3.Overall,it was revealed that PPy/PDA/AgNW composites with tunable electrical conductivity and low density could be applied to electronic components,electrostatice protection and EMI shielding materials.