Biodegradable antistatic plasticizer based on citrate electrolyte doped with alkali metal salt and its poly(vinyl chloride) composites

An eco-friendly citrate electrolyte-based antistatic plasticizer (CEAP) consisting of sodium thiocyanate-doped tris(2-butoxyethyl) citrate was successfully synthesized using a typical esterification reaction between citric acid and 2-butoxyethanol. Poly(vinyl chloride) (PVC)/CEAP composites were then prepared in a Haake torque rheometer. Fourier transform infrared spectroscopy was used to confirm both the structure of the synthesized CEAP and the coordination effects between the doping salt and CEAP. The dependence of the conductivity of the synthesized CEAP on temperature and concentration of the doping salt was investigated. The surface resistivity and mechanical properties of the PVC/CEAP composites were also studied. The results showed that the surface resistivity of the PVC/CEAP composites could be effectively reduced to the order of 10(7) Omega sq(-1) when the CEAP content reached 80 phr. The surface resistivity of the composites still reached 10(8) Omega sq(-1) even at a relative humidity of 12%, showing an excellent electrostatic discharge (ESD) capacity. The fabricated composites with good ESD capacity also had a tensile strength of 10 MPa and an elongation at break of 400%, which could satisfy requirements for packaging applications or similar usages. (C) 2010 Society of Chemical Industry