Banca de QUALIFICAÇÃO: JOSÉ ALBERTO BATISTA DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JOSÉ ALBERTO BATISTA DA SILVA
DATA : 29/05/2018
HORA: 14:00
LOCAL: Sala de aula do química 1
TÍTULO:

OBTATION OF NEW BIOLUBRICANTS USING ALTERNATIVE CATALYTIC ROUTES AND ASSESSEMENT OF OXIDATIVE STABILITY WITH NATURAL ANTIOXIDANTS

PALAVRAS-CHAVES:

Biolubricants; Antioxidants; Oxidative stability; Heterogeneous catalysis; Physicochemical characterization.

PÁGINAS: 120
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Síntese Orgânica
RESUMO:

Researchers from diverse institutions are joining efforts in global scope in order to reduce dependence on petroleum products and minimize the impact of its derivatives on the environment. Vegetable oils are being investigated as a potential source of environmentally friendly lubricants, given the combination of biodegradability, sustainability and excellent lubrication performance. However, some characteristics such as low thermal and oxidative stability, poor cold flow properties and a strait range of available viscosities restrict their potential application as industrial biolubricants. The chemical modification of the fatty acid structures of vegetable oils has a great potential to improve the physicochemical properties of these materials. Thus, in this work, were developed alternative catalytic routes for the synthesis of new biolubricants, with physicochemical and lubrication characteristics similar to commercial base oils, by reacting vegetable oils abundant in linoleic, oleic and palmitic acid with alcohols as propylene glycol and benzyl alcohol. Catalysts have been developed, as well as natural antioxidants, in order to assist in obtaining and optimizing the properties of the new materials. The biolubricants were characterized according to the main technical standards of the American Oil Chemist's Society (AOCS), Adolfo Lutz Institute (IAL) and American Society for Testing and Materials (ASTM), such as viscosity index, pour point, acidity index, humidity and volatile contents and oxidative stability, among others. ¹³C and ¹H nuclear magnetic resonance (NMR) and Fourrier transform infrared (FT-IR) spectroscopy confirmed the chemical modification of the vegetable oil structure, and the liquid chromatography coupled to mass spectrometer (LC-MS) will be used to confirm the structures obtained. The steps presented in the thermogravimetric analysis (TG/DTG) indicated that the products presented satisfactory thermal stability. For the catalytic stage, 04 heterogeneous catalysts were developed, where 03 are based on residual biomass and another one is a bimetallic supported on silica, whose X-ray diffractograms (XRD) indicated the modification of the amorphous silica structure used as support and the presence of peaks referent to the metal oxides present in the catalysts. The antioxidants produced presented considerable efficiency for reducing the lipid oxidation of the oils developed in this work.

MEMBROS DA BANCA:
Presidente - 1805556 - LUCIENE DA SILVA SANTOS
Interno - 1523912 - TATIANA DE CAMPOS BICUDO
Interno - 2087667 - TIAGO PINHEIRO BRAGA