Phenol-Formaldehyde Resin to Improve Corrosion Resistance of Zinc Layers

The present work has the purpose to study and to evaluate the corrosion resistance of zinc layers and phenol – formaldehyde resin/Zn composite layers obtained by electrodeposition. For the best results it was used different parameters for electrodeposition such as: current density between 3 – 5 A/dm2, time for electrodeposition: 30 minutes and 60 minutes, stirring rate: 500 rpm and 800 rpm. Different sizes (mean diameter size between 0.1 – 5.0μm and 6.0 – 10.0μm) of dispersed phases were used with concentration into electrolyte solution from 10g/L to 25 g/L of polymer particles. The morphology of the layers was investigated by SEM – EDX methods. The surface morphology of composite layers was different as compared with pure zinc layers. By adding polymer particles into zinc electrolyte during electroplating a very good distribution of polymer on zinc layer surface was obtained. The electrochemical behavior of the composite layers in the corrosive environment was investigated by polarization potentiodynamic and electrochemical impedance spectroscopy methods. As electrochemical test solution 0.5M sodium chloride was used in a three electrode open cell.

Download Full-text

Evaluation of Corrosion Resistance in 3.5% NaCl Solution of Hybrid Coatings Obtained from Plastics Materials

Materiale Plastice ◽

10.37358/mp.21.1.5459 ◽

2021 ◽

Vol 58 (1) ◽

pp. 201-209

Author(s):

Alina Crina Muresan ◽

Daniela Laura Buruiana ◽

Gabriel Bogdan Carp ◽

Sorin Berbece ◽

Constantin Trus

Keyword(s):

Corrosion Resistance ◽

Corrosion Rate ◽

Disperse Phase ◽

Phenol Formaldehyde ◽

Corrosion Current ◽

Phenol Formaldehyde Resin ◽

Hybrid Coatings ◽

Formaldehyde Resin ◽

Nacl Solution ◽

Plastic Materials

In this work, the corrosion resistance of hybrid coatings obtained from plastic materials was evaluated and compared with the corrosion resistance of Zn coatings. Zinc and hybrid coatings were obtained by electrodeposition from zinc sulphate electrolyte. For obtained hybrid coatings it was used as disperse phase two type of plastic materials: phenol-formaldehyde resin and epoxy resin. Polarization was used to measure the corrosion rate and behaviour of zinc and hybrid coatings in 3.5% NaCl solution. Tafel curves show that the including particles of plastic materials in zinc matrix disturbs the cathodic reactions and reduces anodic reaction leading to decrease of corrosion current and increase the corrosion resistance of hybrid coatings obtained at the same electrodeposition parameters as zinc coatings. Smallest values of corrosion rate were evaluated for hybrid coatings obtained with phenol-formaldehyde resin as disperse phase that indicates a good corrosion resistance in 3.5% NaCl solution.

Download Full-text

Purification of water contaminated with heavy metals by example of lead as promising material based on graphene nanostructures

Perspektivnye Materialy ◽

10.30791/1028-978x-2020-9-34-43 ◽

2020 ◽

pp. 34-43

Author(s):

N. R. Memetov ◽

◽

A. V. Gerasimova ◽

A. E. Kucherova ◽

◽

...

Keyword(s):

Adsorption Process ◽

Phenol Formaldehyde ◽

Phenol Formaldehyde Resin ◽

Formaldehyde Resin ◽

Parameter Estimates ◽

Maximum Adsorption Capacity ◽

Ecological Situation ◽

Characteristic Parameters ◽

Purification Of Water ◽

Graphene Nanostructures

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.

Download Full-text