Preparation Of PPy/Cellulose Conductive Fabric And Property Analysis

PPy is a kind of typical conductive polymer and has been extensively applied due to its high conductance, nontoxicity, easily doping and environmental stability. PPy can be synthesized by chemical or electrochemical method and doped with different ion to obtain better conductive property. However, PPy can not be dissolved and liquated, which has limited its processing. PPy film has been prepared to resolve those problems in most researches. But the PPy film was brittle and had bad strength. PPy/fabric composite was prepared to overcome the disadvantages and has good strength and flexibility.Flax fabric was coated with PPy by in-situ absorption polymerization and admicellar polymerization in this paper.In-situ absorption polymerization is a simple method, in which the effects of various parameters during the processing were investigated. The optimum conditions for preparation are as follows:pyrrole concentration 0.2 moL·L-1, adsorption time 50 min, FeCl3 concentration 0.3 moL·L-1, polymerization temperature 0℃, polymerization time 6 h. The surface resistivity of PPy/cellulose conductive fabric so formed was 1.2Ω·cm-2.Admicellar polymerization is a new method to prepared PPy/cellulose conductive fabric; the effects of various parameters during the processing were also investigated. The optimum conditions for preparation are as follows:surfactant, PVA, PVA to pyrrole weight ratio 2%, pyrrole concentration 0.3 moL·L-1, adsorption time 2.5 h, FeCl3 concentration 0.3 moL·L-1, polymerization temperature 0℃, polymerization time 9 h. The surface resistivity of PPy/cellulose conductive fabric was 0.62Ω·cm-2.Electromagnetic shielding test showed that shielding effectiveness (SE) of double layer composite was 40 dB which can meet the need of the related standard; FTIR spectrums confirmed that the composite was composed of PPy and flax; SEM micrographs showed that PPy deposited on fabrics by in-situ absorption polymerization was interpenetrating polymer network and loosely disperse on the surface. PPy deposited by admicellar polymerization was well-knit, and the particle was smaller than that by in-situ absorption polymerization. The PPy layer was very uniform and compact. XPS showed that nitrogen content in the composite prepared by in-situ absorption polymerization was higher than that by admicellar polymerization. But the latter one's conductive property is better because the particles are smaller and well connect each other. The X- ray diffraction indicates that the addition of PPy don't effect the crystallinity of cellulose substrate. Thermogravimetric (TG) curves of PPy/cellulose conductive fabric shows that its thermostability is better than flax.The surface resistivity of PPy/cellulose conductive fabric almost linearly increased with the prolongation of storage time. The stability of the conductive composite is best when PVA to pyrrole weight ratio is 2%.