Graphene Dispersion As A Packing Aids In The DOW331 For Anticorrosion Coatings

Graphene, as one of the most important nanofillers in developing novel polymer nanocomposites, has been considered to be a promising candidate for the development of advanced nanocomposites because of its chemically inert, excellent mechanical,impermeable to gas molecules and environmentallyfriendly properties. Accordingly, graphene has been proved to be a good diffusion barrier and also been considered to act as a good ultrathin anticorrosion coating. Nowadays, graphene coatings prepared by chemical vapor deposition have provided effective resistance against air, hydrogen peroxide and even aggressive chloride environment. However, on account of the large specific surface area, strong ?-? interaction and van de Waals forces, the graphene sheets can become agglomerated easily, which greatly limits their further applications. Therefore, the availability of large quantities of well dispersed graphene is prerequisite for developments of most promising anticorrosion polymer nanocomposites. In general, chemical modifications and noncovalentfunctionalizations have been used to exfoliate graphene.The harsh reaction conditions in chemical modification are prone to cause structural defects, which inevitably change their thermal conductivities and electrical properties.Compared to chemical modification, noncovalent functionalizations are considered to be a green method because of the mild reaction conditions, easy of control and high efficiency.This paper studies the impact of the epoxy coating performance by using the polymer-modified graphene and the graphene dispersion of the reactive diluentt. Due to the strong intermolecular attraction, both the pristine polypyrrole (Ppy) and graphene (G) tend to aggregate. However, oxidative polymerization of pyrrole in the presence of 1-3 wt% graphene resulted in the transformation of the large and interconnected sphere-like Ppy particles into the fragmented and separated sheet-like Ppy@G composites. Incorporation of the Ppy@G pigments into the epoxy coatings led to the significantly enhanced anticorrosion, whereas the mass fractions of graphene in the whole coating system were only 0.05,0.1 and 0.15 wt%. The large specific surface area of the sheet-like Ppy@G pigments couldgreatly extend the path for the corrosion species to reach the steel substrates. The rheological properties and dielectric properties also greatly improved compared with pure Ppy/epoxy. the Ppy(97)@G(3) increased the thermal curing temperature (Tc) from approximately 100 to 110 ?, and the Volume resistivity decreased greatly. This results attribute the substantially improved properties to high dispersion of Ppy/G composites, which greatly enhanced the corrosion factors barrier properties.It also prepared a reactive diluent dispersed graphene-based epoxy composites and we report on the exceptional application of it for corrosion protection of steel. First of all,we prepared different dispersions of graphene-sheets with the epoxy ring pentane and 1,2 epoxy hexane and the morphology microscopy of graphene-epoxy composites was characterized by scanning slectrom microscopy(SEM) and Transmission electron microscopy (TEM),implying good dispersion of graphene-nano sheets.This work is very clever use of the structure characteristics of the epoxyring pentane.It not only reduced the viscosity of epoxy resin (non-volatile on the curing process),but also can be a very good dispersion of graphene. the result has proved that the preparation of graphene-epoxy composite matirials has good basic performance,such as good mechanical properties, hardness, thermal conductivity etc. More important is that it has good corrosion resistance.