| Texto completo | |
| Autor(es): |
Trentin, Andressa
[1]
;
Gasparini, Andressa de L.
[1]
;
Faria, Flavio A.
[1]
;
Harb, V, Samarah
;
dos Santos, Fabio C.
[2]
;
Pulcinelli, Sandra H.
[2]
;
Santilli, V, Celso
;
Hammer, Peter
[3]
Número total de Autores: 8
|
| Afiliação do(s) autor(es): | [1] Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil
[2] Harb, Samarah, V, Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil
[3] Santilli, Celso, V, Harb, Samarah, V, Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil
Número total de Afiliações: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Progress in Organic Coatings; v. 138, JAN 2020. |
| Citações Web of Science: | 4 |
| Resumo | |
This work reports a detailed investigation of the structural and electrochemical barrier properties of PMMA-silica coatings. Hybrid nanocomposites were prepared by combining the sol-gel method with the polymerization of methyl methacrylate (MMA), using the thermal initiator benzoyl peroxide (BPO), followed by the hydrolytic condensation of tetraethoxysilane (TEOS) and 3-(trimethoxysilyl)propyl methacrylate. Raman spectroscopy and thermal analysis showed that the fine-tuning of the BPO amount, a critical synthesis parameter, improved the polymerization efficiency of MMA, leading to a highly cross-linked hybrid structure. The homogeneous coatings prepared under optimized synthesis conditions presented elevated thermal stability due to improved polymerization of the organic phase. Electrochemical impedance spectroscopy (EIS) showed a quasi-ideal capacitive impedance response in 3.5% NaCl solution, with low frequency impedance modulus of up to 10 G Omega cm(2), which remained essentially unchanged during 19 months of immersion. This notable barrier property was modeled by fitting the EIS curves assuming slowly expanding electrolyte uptake, using the two-layer Young approach, and by comparison with the standard equivalent electrical circuit (EEC/CPE) model. The Young model provided valuable information on the time evolution of physical parameters including the thickness of the uptake zone, the conductivity depth-profile and the dielectric constant, among others, evidencing the high performance of the coatings. (AU) | |
| Processo FAPESP: | 14/12182-9 - Análise mecânica por nanoindentação, microscratch e testes de desgaste de revestimentos anticorrosivos híbridos siloxano-PMMA reforçados por nanotubos de carbono e grafeno |
| Beneficiário: | Samarah Vargas Harb |
| Linha de fomento: | Bolsas no Exterior - Estágio de Pesquisa - Mestrado |
| Processo FAPESP: | 15/11907-2 - Estrutura e propriedades eletroquímicas de revestimentos híbridos PMMA-silica modificados com ions cério e lítio. |
| Beneficiário: | Andressa Trentin |
| Linha de fomento: | Bolsas no Brasil - Doutorado |
| Processo FAPESP: | 15/09342-7 - Desenvolvimento de híbridos PMMA-(TiO2, ZrO2 e CeO2) multifuncionais |
| Beneficiário: | Samarah Vargas Harb |
| Linha de fomento: | Bolsas no Brasil - Doutorado |