| Full text | |
| Author(s): |
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]
Total Authors: 8
|
| Affiliation: | [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
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Progress in Organic Coatings; v. 138, JAN 2020. |
| Web of Science Citations: | 4 |
| Abstract | |
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) | |
| FAPESP's process: | 15/09342-7 - Development of multifunctional PMMA- (TiO2, ZrO2 and CeO2)hybrids |
| Grantee: | Samarah Vargas Harb |
| Support type: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 15/11907-2 - Structure and electrochemical properties of PMMA-silica hybrid coatings modified with cerium and lithium ions. |
| Grantee: | Andressa Trentin |
| Support type: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 14/12182-9 - Mechanical analysis by nanoindentation, microscratch and wear tests of anticorrosive siloxane-PMMA hybrid coatings reinforced by carbon nanotubes and graphene |
| Grantee: | Samarah Vargas Harb |
| Support type: | Scholarships abroad - Research Internship - Master's degree |