Preparation And Antistatic Properties Of Carbon Black/Nylon 6 Composites

Nylon 6(PA6)is the first large engineering plastic,and PA6 fiber is one of the varieties with excellent performance and wide application in synthetic fiber.However,PA6 has high insulation and cannot release static electricity generated by friction or extrusion in time.A huge security risk.The addition of conductive filler to the polymer can effectively improve the antistatic property of the material,and the uniform dispersion of the conductive filler is a key factor determining the antistatic property of the composite.In this paper,the surface modification of carbon black(CB)was carried out by two different modification methods:firstly,CB was used as raw material and sodium polystyrene sulfonate(PSS)was used as modifier to modify the surface physical properties of CB to prepare PSS coating CB(PSS-CB).Secondly,PDA adhered CB(PDA-CB)was prepared by self-polymerization of polydopamine(PDA)on the surface of CB with dopamine hydrochloride(DA-HCl).The chemical and physical structures of CB before and after modification were further characterized and analyzed by Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TG)and Zeta potential.The modified CB prepared by different methods was applied to the antistatic modification of PA6 material.The CB dispersion and interfacial properties of composite materials and composite fibers were carefully studied,and the electrical resistance and mechanical properties were systematically compared and analyzed.The specific research results were as follows:1.The surface modification of CB was carried out by physical method,and the modified CB was characterized by FTIR and TG.The experimental results showed that PSS was successfully coated on the surface of CB,the coating amount was about 5.46 wt%.The absolute value of the Zeta potential of the modified CB increased from 9.12 mV to 19.50 mV,and the results of SEM electron microscopy show that the modified PSS-CB was uniformly dispersed in the PA6 matrix,and it was easier to overlap each other to form a stable conductive network.Therefore,adding 1 wt%could have antistatic properties and better effect.The modified PSS-CB could further improve the mechanical properties of the material.When 1 wt%was added,the tensile strength of the PSS-CB/PA6 composite reached 56.9 MPa,which was 1.17 times higher than that of CB/PA6 composite material before modification.2.The surface modification of CB by chemical method was carried out,and the modified CB was characterized by FTIR and TG.The experimental results showed that PDA successfully adhered to the surface of CB,the adhesion amount was about 17.87 wt%.The absolute value of the zeta potential of the modified CB increased from 9.12 mV to 30.20 mV,combined with SEM electron microscopy results showed that the modified PDA-CB was evenly dispersed in the PA6 matrix,and it was easier to overlap each other to form a stable conductive network.So adding 1 wt%could have antistatic properties and better effect.The post-strain PSS-CB could further improve the mechanical properties of the material.When 1 wt%was added,the tensile strength of the PDA-CB/PA6 composite reached 55.6 MPa,which was 1.14 times of the tensile strength of the CB/PA6 composite before modification.3.PSS-CB/PA6 and PDA-CB/PA6 composite fibers were prepared by melt spinning method.The dispersion of PSS-CB and PDA-CB and the properties of composite fibers in composite fibers were systematically compared.The results of comparative studies showed that PDA-CB could be more uniformly dispersed in PA6 due to the more active groups on the surface of PDA-CB,so the dispersion of PDA-CB in PA6 was more uniform.At lower addition levels,disperse uniform PDA-CB could form a stable conductive network,so that PDA-CB/PA6 composite fiber could achieve antistatic requirements(1 wt%,3.33×102 Ω,1.58×108 Ω·cm).Meanwhile,due to PDA-CB it had a better interaction with the PA6 matrix.When the content was 1 wt%,the tensile strength of PDA-CB/PA6 composite fiber reached 3.1 cN/dtex,which was 1.19 times of the tensile strength of PSS-CB/PA6 composite fiber and 1.24 times the strength of pure PA6 fiber,showing a good strengthening effect;thermal analysis results showed that PSS-CB could effectively improve the thermal decomposition temperature of PA6,and the improvement of PA6 heat resistance was more obvious.