Preparation And Property Study Of Polyaniline/Polyester Composite Conductive Fabric

Polyaniline shows attractive prospects in many respects, easy to prepare, cheap raw material,high conductivity,environmental stability,etc. But the insolubility and non-melting of this material have limited its further processing。However, deposition of polyaniline on conventional fiber will provide a composite fabric which possesses the good conductivity of polyaniline and the flexible property of fiber fabric.At present polymerization in situ is the main method of preparing polyaniline composite conductive fabric. But the material made in this way has shown weak fastness of polyaniline on the matrix fabric; lower deposition of polyaniline also leads to lower conductivity.In this study, the microscopic surface of the matrix fabric was significantly modified by treatment of polyester fabric with alkali at low concentration and using plasma of low temperature. The composite conductive fabric was then prepared by in situ polymerization to form polyaniline layers on the surface of polyester fabric. The main influencing factors of pretreatment which have been studied include concentration of alkali,alkali deweighting time,alkali deweighting temperature,and the pressure, power, processing time of low temperature plasma. The influence of these factors on the surface resistivity of composite conductive fabric has been established. Meanwhile, for the process of in situ polymerization, the concentration of monomer,concentration of ammonium persulfate, oxidation reaction time, and the type and concentration of doping acid have also been investigated. Alkali deweighting with NaOH (20 g/L) at 90℃for 90 minutes and low temperature plasma (300 W, 30 Pa, 4 minutes) were the optimum conditions for pretreatment. In situ polymerization was best carried out with ammonium persulfate (0.025g/ml) as oxidant; hydrochloric acid as the doping acid (0.6mol/L). The preprocessed fabric was first immersed in a solution of aniline monomer (0.3mol/L) for 1.5 hours; oxidative polymerization for 90 minutes produced a composite conductive fabric with the lowest surface resistivity of 0.07 KΩ.The structures and properties of the polyaniline polyester composite conductive fabric were researched. Infrared spectral analysis shows the deposition of polyaniline on the fiber surface. In the SEM (scanning electron microscopy) images, a large number of concave grooves and bump things are observed after pretreatment of fabric fiber, which will benefit the deposition of polyaniline. On the surface of polyaniline composite conductive fabric fiber, there are lots of homogeneous reticulations,namely polyaniline grains,which can form the conductive pathways on the polyester surface.X-ray diffraction and DSC analysis show that polyaniline enters the theamorphous area of polyester fiber and the crystallization perfect degree of parts of polyester molecules is thus reduced. Tg analysis shows that the thermal stability of the polyester fabric has been improved because of the presence of polyaniline.After pretreatment of fabric fiber surface by the alkali deweighting-low temperature plasma technology,the K/S value of composite conductive fabrics gets bigger,which demonstrates a high adsorption of polyaniline on the conductive fabrics. The mechanical properties of composite fabric were insusceptible, based on the analysis of mechanics performance.Our research clearly shows that the polyaniline composite conductive fabric prepared in this way has certainly improved shielding effectiveness, the surface resistivity can be 0.89 K? even after 5 times of ultrasonic washing. This novel fabric will find wide applications in industry.