Evaluation of the self-healing properties of polyurethane coatings derived from ve...
| Grant number: | 15/10554-9 |
| Support type: | Scholarships in Brazil - Doctorate |
| Effective date (Start): | October 01, 2015 |
| Effective date (End): | March 31, 2020 |
| Field of knowledge: | Physical Sciences and Mathematics - Chemistry |
| Principal Investigator: | Assis Vicente Benedetti |
| Grantee: | Jéssica Verger Nardeli |
| Home Institution: | Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil |
| Associated scholarship(s): | 18/09040-9 - Evaluation of the self-healing properties of polyurethane coatings derived from vegetable oils with and without addition of corrosion inhibitors using localized electrochemical techniques and the study of chemical and structural properties, BE.EP.DR |
Abstract In this project it is proposed the preparation from vegetable oils, and morphological, chemical and electrochemical characterization of organic coatings as resins. The organic coatings are designed to protect aluminum alloys such as ASTM 1200 and ASTM 5052 or ASTM 7075 against corrosion in aggressive media. Various types of microscopy, spectroscopy in the infrared, Raman scattering and electrochemical conventional and localized techniques are going to be employed in this study. The organic coatings are going to be obtained in four steps: (1) transesterification of crambe oil and KOH in CH3OH, followed by characterization of the product; (2) synthesis of hydroxylated polyesters by polyesterification using the ester obtained in (1) with different ratios of phthalic anhydride and trimethylol propane, and monitoring of the product; (3) mixing the toluene diisocyanate (TDI) with oxygenated solvents ethyl acetate and ethylglycol acetate; (4) obtaining the polyurethane resin mixture in proportions 1: 2 and 1: 3 the polyesters with the hydroxylated prepolymer. In this step (4) corrosion inhibitors obtained as extracts from water hyacinth plant are going to be incorporated. The coatings are going to be applied to the Al alloy by spraying, dipping or other procedure. Curing of the coatings will be conducted at room temperature and at accelerated conditions. After the chemical, structural and morphological characterization of the coatings the electrochemical studies will be performed. The corrosion resistance and the film degradation process in NaCl 3.5% aqueous will be evaluated by potential measurements at open circuit, linear and cyclic polarization curves, DC resistance, and electrochemical impedance spectroscopy techniques such as local electrochemical impedance spectroscopy and scanning vibrating electrode technique. The porosity of the coatings will be evaluated from electrochemical measurements. | |