Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid
Autor(a) principal: | |
---|---|
Data de Publicação: | 2011 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000200004 |
Resumo: | The performance of triethylenetetramine-tribenzylidene (TTTB) and triethylenetetramine-trisalicylidene (TTTS) as corrosion inhibitors for zinc in hydrochloric acid is investigated. At lower concentrations, both inhibitors accelerate the attack but inhibit corrosion at higher concentrations, e.g., 96-100% with 1.0% concentration in 0.5 M and 1.0 M HCl. The efficiency of TTTB decreases while that of TTTS remains almost constant (≥ 99.7%) up to 120 minutes and in the temperature range 35 - 65 ºC. The activation energies are higher in inhibited than in plain acid with both inhibitors. The free energy of adsorption (ΔGads) and heat of adsorption (Qads) are negative, which suggests that there is spontaneous adsorption on metal surface, and from the values of (ΔGads) and (Qads), the values of entropy of adsorption (ΔSads) were calculated. Galvanostatic polarization shows that corrosion is under mixed control with predominance of the cathodic part. In uninhibited 1.0 M HCl, complete cathodic protection is achieved at a current density of 4.2224 Adm-2, but in presence of these inhibitors, much lower current densities are required. Plot of log (θ/1-θ) versus log Cinh gives a straight line, suggesting that inhibitors cover both the anodic and cathodic regions through general adsorption following Langmuir isotherm. The mechanism of inhibition has been proposed. |
id |
RCAP_5e8c5f67d1d2cf90575baea26688456f |
---|---|
oai_identifier_str |
oai:scielo:S0872-19042011000200004 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
|
spelling |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acidcorrosionzinchydrochloric acidinhibitorThe performance of triethylenetetramine-tribenzylidene (TTTB) and triethylenetetramine-trisalicylidene (TTTS) as corrosion inhibitors for zinc in hydrochloric acid is investigated. At lower concentrations, both inhibitors accelerate the attack but inhibit corrosion at higher concentrations, e.g., 96-100% with 1.0% concentration in 0.5 M and 1.0 M HCl. The efficiency of TTTB decreases while that of TTTS remains almost constant (≥ 99.7%) up to 120 minutes and in the temperature range 35 - 65 ºC. The activation energies are higher in inhibited than in plain acid with both inhibitors. The free energy of adsorption (ΔGads) and heat of adsorption (Qads) are negative, which suggests that there is spontaneous adsorption on metal surface, and from the values of (ΔGads) and (Qads), the values of entropy of adsorption (ΔSads) were calculated. Galvanostatic polarization shows that corrosion is under mixed control with predominance of the cathodic part. In uninhibited 1.0 M HCl, complete cathodic protection is achieved at a current density of 4.2224 Adm-2, but in presence of these inhibitors, much lower current densities are required. Plot of log (θ/1-θ) versus log Cinh gives a straight line, suggesting that inhibitors cover both the anodic and cathodic regions through general adsorption following Langmuir isotherm. The mechanism of inhibition has been proposed.Sociedade Portuguesa de Electroquímica2011-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articletext/htmlhttp://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000200004Portugaliae Electrochimica Acta v.29 n.2 2011reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAPenghttp://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000200004Shah,M.D.Patel,A.S.Mudaliar,G.V.Shah,N.K.info:eu-repo/semantics/openAccess2023-07-27T12:23:25ZPortal AgregadorONG |
dc.title.none.fl_str_mv |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
title |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
spellingShingle |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid Shah,M.D. corrosion zinc hydrochloric acid inhibitor |
title_short |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
title_full |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
title_fullStr |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
title_full_unstemmed |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
title_sort |
Schiff Bases of Triethylenetetramine as Corrosion Inhibitors of Zinc in Hydrochloric Acid |
author |
Shah,M.D. |
author_facet |
Shah,M.D. Patel,A.S. Mudaliar,G.V. Shah,N.K. |
author_role |
author |
author2 |
Patel,A.S. Mudaliar,G.V. Shah,N.K. |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Shah,M.D. Patel,A.S. Mudaliar,G.V. Shah,N.K. |
dc.subject.por.fl_str_mv |
corrosion zinc hydrochloric acid inhibitor |
topic |
corrosion zinc hydrochloric acid inhibitor |
description |
The performance of triethylenetetramine-tribenzylidene (TTTB) and triethylenetetramine-trisalicylidene (TTTS) as corrosion inhibitors for zinc in hydrochloric acid is investigated. At lower concentrations, both inhibitors accelerate the attack but inhibit corrosion at higher concentrations, e.g., 96-100% with 1.0% concentration in 0.5 M and 1.0 M HCl. The efficiency of TTTB decreases while that of TTTS remains almost constant (≥ 99.7%) up to 120 minutes and in the temperature range 35 - 65 ºC. The activation energies are higher in inhibited than in plain acid with both inhibitors. The free energy of adsorption (ΔGads) and heat of adsorption (Qads) are negative, which suggests that there is spontaneous adsorption on metal surface, and from the values of (ΔGads) and (Qads), the values of entropy of adsorption (ΔSads) were calculated. Galvanostatic polarization shows that corrosion is under mixed control with predominance of the cathodic part. In uninhibited 1.0 M HCl, complete cathodic protection is achieved at a current density of 4.2224 Adm-2, but in presence of these inhibitors, much lower current densities are required. Plot of log (θ/1-θ) versus log Cinh gives a straight line, suggesting that inhibitors cover both the anodic and cathodic regions through general adsorption following Langmuir isotherm. The mechanism of inhibition has been proposed. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011-01-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000200004 |
url |
http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000200004 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000200004 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Portuguesa de Electroquímica |
publisher.none.fl_str_mv |
Sociedade Portuguesa de Electroquímica |
dc.source.none.fl_str_mv |
Portugaliae Electrochimica Acta v.29 n.2 2011 reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
|
repository.mail.fl_str_mv |
|
_version_ |
1777304406805446656 |