Poly(m-phenylenediamine) encapsulated graphene for enhancing corrosion protection performance of epoxy coatings

Abstract

Graphene (G) is regarded as a tremendous potential corrosion protection material owing to its perfect impermeability. However, the tendency of graphene nanosheets to agglomerate and the corrosion-promotion effect brought by its native high electrical conductivity seriously affect its anti-corrosion application. In this paper, high-energy ball milling was used to prepare graphene with excellent impermeability. Then, insulating poly(m-phenylenediamine) encapsulated graphene (G@PmPD, conductivity of 1.2 × 10−7 S cm−1) was prepared through non-covalent π–π interaction. The resulting amino-rich G@PmPD exhibits stable dispersibility and excellent compatibility in organic solvents and polymer matrix. Embedding 0.5 wt% of G@PmPD into the epoxy matrix, and the composite coating can effectively protect the steel substrate for up to 60 d. This superior corrosion resistance is attributed to the impermeability inherited by G@PmPD and the compactness improved by the cross-linking of G@PmPD and EP. Especially in the damaged state, the composite coating embedded with low conductivity G@PmPD triumphantly eliminated graphene’s corrosion-promotion effect. This study provides promising inspiration for the application of graphene in anti-corrosion field.

Thermal conductive nylon 6 composites using hybrid fillers to construct a three‐dimensional thermal conductive network

“…In this work, a facile method to construct a 3D thermally conductive network using fillers of different sizes is proposed. First, graphene nanosheets (EX‐G) were obtained from our previous work 42 . EX‐G and CF were non‐covalently functionalized by PDA to form reactive sites on the inert surface, and then 3‐aminopropyltriethoxysilane (KH550) was used to treat Al 2 O 3 and non‐covalently functionalized graphene (EX‐G@PDA), noncovalently functionalized carbon fibers (CF@PDA) were treated with 3‐glycidyloxypropyltrimethoxysilane (KH560) to enhance dispersion in the matrix.…”

“…First, graphene nanosheets (EX-G) were obtained from our previous work. 42 EX-G and CF were non-covalently functionalized by PDA to form reactive sites on the inert surface, and then 3-aminopropyltriethoxysilane (KH550) was used to treat Al 2 O 3 and non-covalently functionalized graphene (EX-G@PDA), noncovalently functionalized carbon fibers (CF@PDA) were treated with 3-glycidyloxypropyltrimethoxysilane (KH560) to enhance dispersion in the matrix. The schematic is shown in Figure 1, during the melt mixing process, the reaction between amino groups and epoxy groups establishes a Coupling modification of CF: Put CF into 200 mL acetone and let it stand for 24 h at room temperature.…”

Effect of quinacridone content on the performance of graphene/epoxy coatings

“…[18][19][20][21] Moreover, organic pigments generally exhibit low electrical conductivity, which can reduce the conductivity of Gr while adsorbed on the surface of Gr, thus avoiding the electrochemical corrosion caused by Gr. 22,23 However, to the best of our knowledge, there is a lack of in-depth studies on the use of aromatic pigments to improve the dispersion of Gr in organic coatings or the performance of organic coatings. In this article, epoxy coatings with different contents of quinacridone (QA) to Gr ratios were prepared by solution mixing method.…”

“…are used extensively in coatings as an important component of fillers and often contain aromatic chromogenic groups which can form π–π non‐covalent bonds with Gr 18–21 . Moreover, organic pigments generally exhibit low electrical conductivity, which can reduce the conductivity of Gr while adsorbed on the surface of Gr, thus avoiding the electrochemical corrosion caused by Gr 22,23 …”