Waterborne polyurethane is a high performance polymer material, it has characteristics of wear resistance, good flexibility, strong adhesion and low film-forming temperature, etc., and has been widely used in many areas. But its poor anti-corrosion ability and antistatic properties make a certain limit to its application. Thereby, other materials are needed to improve its propeties. This paper summarizes the related research on the modification of waterborne polyurethane with PEDOT and graphene.

PEDOT

Poly(3,4-Ethylene dioxythiophene) (PEDOT) is a novel conductive polymer material, the monomer is 3,4-ethylenedioxythiophene (EDOT). PEDOT has a higher conductivity and a higher transmittance to visible light. In the oxidized state, the PEDOT film is almost transparent and can be used for the preparation of electronic devices. However, PEDOT is an insoluble polymer, so its use is severely limited.

Zhou Xu et al. [1] used PEDOT/PSS as water-soluble antistatic agent and added to the polyurethane, they optimized the technique of PEDOT polymerization process, and the anti-static coating are in line with the state standards. The antistatic coating has the advantages of low surface resistivity, good adhesion, high hardness and good water resistance. It can be used in the field of electronic packaging materials and electronic trays, and has a wide application prospect. However, PSS is a nonconductive flexible template that requires the use of large and expensive EDOT monomers for further polymerization preparation.

Graphene oxide

Graphene is a two-dimensional crystal that is packed with carbon atoms and has many excellent properties of graphite and carbon nanotubes, such as ultra-thin, ultra-light, ultra-high strength, high conductivity, light transmission and structural stability. It is regarded as a new high-performance nano-reinforced body, which bring a wide range of performance improvements for the polymer composite materials, and as an antistatic agent, graphene has a great advantage. Fei Guiqiang et al. [2] use graphene as water-based filler to add to water borne polyurethane, the composite coating has a broad application prospects in the anti-corrosion coating, but because graphene oxide is not conductive, the coating is not with anti-static function.

rGO/PEDOT

Yuan Yan, et al. [3] made EDOT monomer in situ polymerization on the graphene oxide layer to prepare partial reduction graphene/poly-3,4-ethylenedioxythiophene (rGO/PEDOT) composite system, which both make up the disadvantage of poor conductivity of graphene oxide and solves the poor water dispersibility of PEDOT. And the rGO/PEDOT composite system can be well dispersed in the water-borne polyurethane, the anti-static coating is in accordance with the national standard GB13348-2009. The antistatic properties, mechanical properties and thermal stability of the coatings are all prominent.

Waterborne polyurethanes have many excellent properties, but the disadvantages also limit the wider application, some measures need to take to improve their performance. The addition of graphene and PEDOT can effectively improve some of its properties, and the combination of the two can overcome their shortcomings, so that the overall performance of waterborne polyurethane coating is more excellent.

references