Investigation on anticorrosion performance of polyaniline‐mesoporous MCM‐41 composites in new water‐based epoxy coating

Abstract

Mesoporous MCM‐41(M(with template)) whose pore channels were filled with cationic surfactant n‐hexadecyltrimethyl‐ammonium bromide (CTAB) and a (hydrophobic) poly(propylene glycol) nucleus terminated by two primary hydroxyl groups (Pluronic F‐127, molecular weight = 11500) inside the pore channels and on the outer surface of the particle, MCM‐41 (M(without template)) whose mixture template inside the pore channels and on the outer surface of the particle were calcinated, were used as new fillers for waterborne epoxy. The corrosion studies were carried out on steel plates coated with formulations containing polyaniline prepared with M(with template) and M(without template). Correspondingly, corrosion performance of the coatings was studied by electrochemical impedance spectroscopy (EIS) in 3.5% NaCl aqueous solution and salt spray test. Coatings prepared from polyaniline (PANI)/M(without template) particles synthesized by in situ polymerization were found to exhibit excellent corrosion resistance much superior to PANI/M(with template) in aggressive environments due to the different interfacial structures between the fillers and the matrix.

Corrosion Resistance of Waterborne Epoxy Coatings by Incorporation of Dopamine Treated Mesoporous-TiO2 Particles

“…Meso-TiO 2 not only has nanoscale size, but also has the unique pore structure compared with normal nanoparticles which could improve the anti-aging properties and barrier properties of the coating. In our previous work, we proved that waterborne epoxy resin has better anticorrosion properties due to the addition of MCM-41 and we also proved that meso-TiO 2 can increase the barrier performance of the coatings more availably due to the larger pore size of meso-TiO 2 than MCM-41 [1,11]. However, due to high surface tension of water, the compatibility between waterborne epoxy matrix and filler is poor.…”

“…The BJH (aperture distribution test) analyses showed that meso-TiO2 exhibited an average poresize of about 5.8 nm calculated from the desorption branch of the nitrogen adsorption isotherm [1]. Table 2 shows that the pore volume of modified with dopamine decreased from 0.235 to 0.074 mL·g −1 compared with the pore volume of meso-TiO2.…”

“…Figure 10a shows that the steps of rust formation on matrix required continuous charge transfer. If the processes were prevented or delayed, the corrosion will be inhibited and the coating becomes effective for corrosion prevention [1]. Firstly, from the point of view of the electrochemical structure, the composite coating modified by DA/meso-TiO 2 would include the elements of S and Ti, in which there were some empty or not full d orbitals.…”

“…Recently, waterborne epoxy resins have occupied a major place in the development of high performance light weight composites due to the unique combination of properties and are more environmentally friendly compared with epoxy resins [1][2][3][4]. Nonetheless, the primary disadvantage of waterborne epoxy resin is the formation of holes and faults over the coated surface [5][6][7].…”

Effect of Graphene Oxide/ZSM-5 Hybrid on Corrosion Resistance of Waterborne Epoxy Coating

“…Various reports have shown that the corrosion resistances of coatings can be improved with the addition of nanoparticles such as TiO2 [16], SiO2 [17], and ZnO [18]. In our previous work, we utilized mesoporous-TiO2 and MCM41 in corrosion-resistant coatings and showed that these nanoparticles enhanced the barrier properties of the coatings by reducing the transport paths for the corrosive electrolytes to pass through the coating system [19,20]. However, the synergistic corrosion protection of molecular sieve and graphene has not been reported in the field.…”