Processable poly(2-butylaniline)/hexagonal boron nitride nanohybrids for synergetic anticorrosive reinforcement of epoxy coating

Hexagonal boron nitride (h-BN), a structural analogue of graphene, is a better alternative for anticorrosive coatings because of its electrical insulation properties. In this work, few-layer h-BN nanosheets are obtained by the exfoliation of stacked h-BN powders with poly(2-butyl aniline) (PBA) and incorporated into epoxy coatings for protecting metallic substrate against corrosion. Results show that as prepared composite coatings exhibit high impedance modulus and low water absorption, suggesting their superior performance of corrosion protection owing to the "labyrinth effect" of h-BN and passivation effect of PBA on the metal substrates

Synthesis and properties of polyimide nanocomposite containing dopamine-modified graphene oxide

Synthesis and properties of polyimide nanocomposite containing dopamine-modified graphene oxid

Dopamine@Nanodiamond as novel reinforcing nanofillers for polyimide with enhanced thermal, mechanical and wear resistance performance

In this study, to achieve a homogeneous dispersion of nanodiamond (ND) in a polyimide (PI) matrix and a strong interfacial adhesion between ND and the PI matrix, a biomimetic nondestructive dopamine chemistry was employed for surface modification of ND. FTIR and Raman spectroscopy studies revealed that self-polymerization of dopamine could produce thinner polydopamine (PDA) layers on the ND surface via spontaneous oxidation and the intermolecular cross-linking reaction of PDA molecules. The structure and morphology of PDA-ND were studied by FTIR, SEM, and Raman spectroscopy, which verified the p-p interactions between PDA and ND. The facile dispersion of PDA-ND in a polyamic acid prepolymer made it possible to obtain PI/ND composites with no obvious ND aggregation. The effect of PDA-ND nanoparticles on the thermal, mechanical and tribological properties of the resulting PI/PDAND composites were evaluated, and the results showed that the incorporation of PDA-ND could increase the hardness, tensile strength, storage modulus, as well as the wear resistance properties. PI/PDA-ND composites prepared in this study showed that PDA-ND is a promising nanoreinforcing filler for PI composites

Functionalized graphene-reinforced rubber composite: Mechanical and tribological behavior study

A functionalized graphene, fluorinated graphene nanosheets (FGS), and SiO2 nanoparticles as reinforcing fillers were employed to improve the mechanical properties of the solution styrene butadiene and butadiene rubber composites (SSBR-BR). The results showed that the mechanical properties of SSBR-BR composite filled with FGS were substantially improved than those of the unfilled and equivalent filler loaded graphene oxide (GO) and reduced graphene oxide (rGO) filled SSBR-BR composites. It can be ascribed to the fact that the hydrophobic surface of FGS can be endowed the good dispersion in rubber matrix and stronger interfacial interaction between rubber and fillers. The tribological properties of these composites are also investigated. The results reveal that incorporation of GO, rGO, and FGS in SSBR-BR composites can decrease antiwear properties because the existence of layered graphene promotes to tear and peel off. (C) 2017 Wiley Periodicals, Inc

Non-covalent functionalized hexagonal boron nitride nanoplatelets to improve corrosion and wear resistance of epoxy coatings

In the present study, a non-covalent method was employed to modify hexagonal boron nitride (h-BN) nanoplatelets through pi-pi interaction of amine-capped aniline trimer (AT), which resulted in a stable dispersion of h-BN nanoplatelets in organic solvents. Meanwhile, epoxy coatings containing different content of h-BN nanoplatelets were fabricated, and corresponding corrosion protection performance and wear resistance were investigated. Results showed that the 1.0 wt% h-BN/ epoxy coating has better corrosion protection performance than other coatings, which was due to the good barrier properties from stably dispersed h-BN nanoplatelets and the passivating effect from AT. Besides, the addition of h-BN nanoplatelets also contributed to the improvement in wear resistance of epoxy the coating

Anticorrosion Performance of Epoxy Coating Containing Reactive Poly (o-phenylenediamine) Nanoparticles

The free amine-containing poly(o-phenylenediamine) (PoPD) nanoparticles with significant dispersibility in organic solvents have been synthesized by chemical oxidative polymerization of o-phenylenediamine mono-hydrochloride salt. The epoxy coatings with different contents of PoPD nanoparticles (0.5 wt%, 1 wt% and 2 wt%) were then prepared by curing reaction of epoxy resin, amine hardener and amine containing PoPD nanoparticles. The corrosion protection properties of the as prepared coatings on Q235 steel were investigated by potentiodynamic polarization, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) technique in 3.5 wt % NaCl aqueous solution for 90 days. The results indicate that the coatings with 0.5 wt% PoPD nanoparticles (0.5-PDEP) exhibits high anticorrosive performance, which is attributed to the improved barrier effect of the nano-fillers and redox catalytic capability of embedded PoPD nanoparticles with the evidence of scanning electron microscope (SEM) and XRD. This novel amine-containing PoPD nanoparticles give a promising way to enhance the anticorrosion performance of epoxy coatings and potentially have a wider range of applications in anticorrosion related engineering applications

Noncovalent Functionalized Graphene-Filled Polyimides with Improved Thermal, Mechanical, and Wear Resistance Properties

A facile method is proposed to prepare poly-o-phenylenediamine (PoPD) noncovalent functionalized graphene (G)-reinforced polyimide (PI) nanocomposites. PoPD-G exhibited excellent dispersibility in various organic solvents. The structures of PoPD-G were characterized by Raman and UV spectrum, which verified the pi-pi interactions between PoPD and G. The effective exfoliation of graphene nanosheets was investigated by observation of the morphology of PoPD-G with SEM, SPM, and TEM. Compared to PI/G composites, the interfacial adhesion between graphene nanosheets and PI matrices promoted efficient stress transfer from PI chains to PoPD-G nanofillers. Polyimide nanocomposites with different incorporations of PoPD-G exhibited outstanding thermal properties. It is interesting to note that only 0.5 wt% PoPD-G-reinforced PI composites increased by 20.8% in hardness, enhanced by 84.0% in storage modulus, and reduced by 72.8% in wear rate compared with neat PI. The eminent enhancement was attributed to the facile dispersion of graphene nanosheets and strong interface adhesion between PI and PoPD-G

Achieving high performance corrosion and wear resistant epoxy coatings via incorporation of noncovalent functionalized graphene

Graphene(G)-based polymer nanocomposites have attracted great interest owing to their superior physicochemical properties over polymers. However, the tendency of graphene sheets to aggregate makes it difficult to achieve homogenous dispersion in polymer matrix. Herein, by utilization of poly(2-butylaniline) (P2BA) as a dispersing agent, stable dispersion of graphene in organic solvents was achieved via non-covalent pi-pi interactions between P2BA and graphene nanosheets. The exfoliated graphene nanosheets were then integrated with coating matrix by curing reaction of epoxy resin with P2BA functionalized graphene (P2BA-G) and amine hardener. Embedding a small percentage of well-dispersed graphene nanosheets (P2BA(0.5%)-G(0.5%)) in epoxy coating remarkably improved anticorrosion performance and wear resistance properties, which was attributed to the synergistic effects of the redox catalytic capability of P2BA, high mechanical and barrier properties of well-dispersed graphene nanosheets in the epoxy matrix. The present study provides a promise strategy for development of graphene reinforced organic coatings with superior physical-mechanical properties for metal protection. (C) 2016 Elsevier Ltd. All rights reserved