Study On The Conductivity Of Modified Carbon Black/Waterborne Polyurethane Coated Textiles

The doped waterborne polyurethane conductive coating has such advantages as the good electrical conductivity and film forming property,simple operation process and friendly environment.It has been widely applied in fabric finishing.The conductive properties of conductive fillers and their dispersion in coatings are the key factors determining the properties of coatings.In many studies,modification of the structure and properties of fillers is an important way to improve the dispersion of fillers in coatings.In this study,carbon black?CB?was modified in two ways:CB was used as core material and polyurethane?PU?as wall material,prepared the carbon black modified particles that coated with polyurethane?PU-CB?.PANI was deposited on CB surface during polymerization process by in-situ polymerization.Fourier transform infrared spectrometer,scanning electron microscope,energy dispersive spectrometer,scanning electron microscope,thermogravimetric analysis,X-ray diffractometer and laser particle size analyzer were used to analyze the structure and performance of the filler before and after modification.The modified particles were applied to the waterborne polyurethane?WPU?conductive coatings.The effects of different types of filler and percentage of fillers on the properties of coatings were studied.The coating is applied to the fabric coating,and studied the conductive and tensile properties of the coated fabric.The conclusion is as follows:The carbon black particles coated with polyurethane were prepared after the modification of CB,The research showed that the modified particles have better coating structure under the reaction conditions of M?CB?:m?IPDI?=6:8,the particle diameter is about 50¹80nm;The mass ratio of CB in the modified particles is about 37%,the particle conductivity is 1.2×10^-2S/cm.Compared with CB,the dispersibility of the modified particles is greatly improved.PANI was deposited on the surface of CB during the polymerization process,and the composite particles of PANI and CB were prepared.The structure of PANI-CB is relatively loose compared to the large aggregation structure of PANI and CB.The conductivity of PANI-CB is higher than that of CB?conductivity of PANI-CB is 8.4×10^-22 S/cm?,and its dispersion in the water is also better than that of CB and PANI.Compared with unmodified CB fillers,the modified filler has lower sedimentation rate,better adhesion and film formation performance when applied to waterborne polyurethane coatings.The results of SEM show that the aggregation of CB in the coating is very serious,and the dispersion of PU-CB in the coating is the best,PANI-CB times.The conductive properties of the coating were increased with the increase of the filler percentage and the minimum volume resistivity of CB/WPU film can reach 3.41×10³?·cm when the filler percentage is 15%;PU-CB/WPU was 1.42×10⁴?·cm when the filler percentage is 10%;PANI-CB/WPU film is 8 x 10²?·cm when the filler percentage is 8%.The addition of packing made the tensile properties of the coating decreased as compared with the WPU coating.The lower?<5%?filler content can enhance the fracture stress of the coating to a certain extent,but with the increase of filler percentage,the fracture stress of the coating decreases,and the influence of filler on the tensile properties of the coating is reduced by modifying the performance.Conductive properties and film coated fabric is similar in filling percentage under the same conditions,the electrical conductivity of PU-CB and PANI-CB coatings can impart the fabric better,the resistivity of PANI-CB/WPU coated fabric is about 102?·cm,compared with CB/WPU coated fabrics decreased by 4 orders of magnitude.Due to the good mechanical properties of WPU,the tensile properties of the fabric after coating are improved.