Banca de DEFESA: WILLIAMS RAPHAEL DE SOUZA MORAIS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : WILLIAMS RAPHAEL DE SOUZA MORAIS
DATE: 30/06/2023
TIME: 10:00
LOCAL: Ambiente virtual
TITLE:

DEVELOPMENT OF GREEN CORROSION INHIBITORS DERIVED FROM PLANT EXTRACTS

KEY WORDS:

Corrosion. green inhibitor. plants. Vegetable extracts. Eucalyptus globulus Labill. Sargassum vulgare. Paullinia cupana. Guarana

PAGES: 163
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Metallic materials and metallic alloys, are widely used as materials in the most diverse areas, due to their advantages. Carbon steel, for example, is the most widely used metal alloy and one of the most widely produced materials in the world.  On the other hand, most metals and their alloys in their pure form are highly reactive and suffer corrosion, a thermodynamically spontaneous process, resulting in their deterioration. One of the most practical methods of protecting materials is the use of corrosion inhibitors. Some inhibitors, however, are potentially polluting and harmful to human health, this motivates the search for new formulations. The literature reports the use of natural products, called "green inhibitors", the plant extracts stand out within this class of inhibitors. In this perspective, in the present work it was accomplished a prospection about the applicability of vegetal extracts as green inhibitors of corrosion and the development of these inhibitors from 3 vegetal extracts of different sources: leaves of Eucalyptus globulus Labill, Sargassum vulgare seaweed and grains of Paullinia cupana (guaraná), in the protection of the 1020 carbon steel. In the prospection bases of scientific articles and patents were consulted and the documents found were analysed. The extracts were characterized by spectroscopic and chromatographic techniques, and their inhibition activities were evaluated by gravimetric and electrochemical techniques. A total of 335 articles and 42 patents related to the theme were retrieved, being most of the extracts prepared from leaves for the protection of carbon steel in acid medium. In the characterization of the extracts were identified types of bonds and compounds, as terpenes and phenolic acids, that demonstrate the possibility of application of these extracts as corrosion inhibitors. The used techniques showed that in all studied concentrations the extracts increased the charge transfer resistance, provoked potential displacement and decreased the parameters related to corrosion, reaching 89.97 % of maximum anticorrosive efficiency. Moreover, the adsorption of molecules, in the presence of the extracts, on active sites of the carbon steel surface was physisorption and obeyed the Frumkin adsorption isotherm. The proposed inhibitors are presented as non-toxic, cheap, abundantly available in nature and of easy extraction, characterizing them as green corrosion inhibitors.

BANKING MEMBERS:
Interno(a) - 2181152 - EDUARDO JORGE DA SILVA FONSECA
Presidente - 1121401 - JOSEALDO TONHOLO
Externo(a) ao Programa - 3297452 - JOSÉ MARCOS DOS SANTOS OLIVEIRA
Interno(a) - 2121376 - MARCOS VINICIUS DIAS VERMELHO
Externo(a) à Instituição - NATHALIA MARCELINO PEREIRA QUEIROZ