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Previous issue date: 2009-07-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work thiosemicarbazones [4-N-cinnamoyl-thiosemicarbazone (CTSC), 4-N-(2'-methoxycinnamoyl)-thiosemicarbazone (MCTSC), and 4-N-(4'-hydroxy-3'-methoxybenzoyl)-thiosemicarbazone (HMBTSC)] were solubilized in an microemulsion system (ME_OCS)
which is rich in aqueous phase (O/W system). The system ME_OCS was obtained with saponified coconut oil (OCS) as (surfactant), butanol (cosurfactant), and kerosene as oil phase (Fo), using 40% of C/T (cosurfactant/surfactant), 5% of Fo and 55% of aqueous phase. The microemulsions systems CTSC_ME_OCS, MCTSC_ME_OCS and HMBTSC_ME_OCS effectiveness on a AISI 1020 carbon steel corrosion inhibition process were evaluated in a saline solution (NaCl 0.5%), using a galavostatic method. The tested thiosemicarbazones (TSC) showed highest inhibitors effects (85.7% for CTSC_ME_OCS, 84.0% for MCTSC_ME_OCS, and 83.3% HMBTSC_ME_OCS) at lower concentrations [0.19% of
CTSC, 0.07% (MCTSC), and 0.26% (HMBTSC)]. Comparatively, the surfactant OCS (solubilized in H2O) as well as the system ME_OCS showed lower efficacy [71% for OCS (at 0.20 - 0.25% of concentration) and 74% for ME_OCS (at 0.5% of concentration)]. Since the microemulsion systems ME_OCS showed satisfactory interfacial adsorption, the greatest inhibitory effect of those TSC_ME_OCS systems could be correlated to both chemical composition of each tested TSC (which is rich in heteroatoms and aromatic ring) and also the presence of the surfactant OCS / Neste trabalho tiossemicarbazonas [4-N-cinamoil-tiossemicarbazona (CTSC), 4-N-(2 -metoxicinamoil)-tiossemicarbazona (MCTSC) e 4-N-(4 -hidroxi-3 -metoxibenzoil)-tiossemicarbazona (HMBTSC)] foram solubilizadas em um sistema microemulsionado do tipo O/A (rico em ?gua). Este sistema (ME_OCS) foi obtido com ?leo de coco saponificado (OCS), butanol (cotensoativo), querosene (fase ?leo) e ?gua, nas seguintes propor??es: 40%
de raz?o C/T (cotensoativo/tensoativo), 5% de fase ?leo e 55% de fase aquosa. Os sistemas microemulsionados contendo as tiossemicarbazonas (CTSC_ME_OCS, MCTSC_ME_OCS e HMBTSC_ME_OCS) foram avaliados como inibidores de corros?o em a?o carbono AISI 1020, em meio salino (NaCl 0,5%), utilizando-se um m?todo galvanost?tico. Estes sistemas apresentaram inibi??es elevadas (85,7% para CTSC_ME_OCS, 84,0% para MCTSC_ME_OCS, e 83,3% para HMBTSC_ME_OCS) em baixas concentra??es (0,19% de
CTSC, 0,07% de MCTSC, e 0,26% de HMBTSC). Comparativamente, o tensoativo OCS (solubilizado em H2O) e o sistema ME_OCS apresentaram menores taxas de inibi??o (71% para OCS, com concentra??o variando entre 0,20 e 0,25% e 74% para ME_OCS, com 0,5% de concentra??o). A maior efic?cia de inibi??o dos sistemas ME_OCS contendo as
tiossemicarbazonas (TSC) poderia estar correlacionada com as estruturas qu?micas (ricas em heteroatomos e anel arom?tico) das TSC avaliadas, bem como com o sistema
microemulsionado ME_OCS que apresenta adsor??o interfacial eficaz
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17604 |
| Date | 27 July 2009 |
| Creators | Moura, Elaine Cristina Martins de |
| Contributors | CPF:13893734449, http://lattes.cnpq.br/2791074318745945, Rossi, C?tia Guaraciara Fernandes Teixeira, CPF:77044568491, http://lattes.cnpq.br/0103853142184734, Dantas, Tereza Neuma de Castro, CPF:07286937391, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783139Z0&dataRevisao=null, Santanna, Vanessa Cristina, CPF:77938780430, http://lattes.cnpq.br/9445575768909084, Maciel, Maria Aparecida Medeiros, Silva, Djalma Ribeiro da |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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