Banca de DEFESA: ANA CLAUDIA DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANA CLAUDIA DOS SANTOS
DATE: 04/11/2022
TIME: 13:00
LOCAL: online
TITLE:

MODIFICATION OF SUGARCANE BAAGASSE FIBERS FOR APPLICATION IN CEMENTARY COMPOSITES AND IN FIPRON ADSORPTION STUDIES

KEY WORDS:

Cementitious compounds, bagasse, stearic acid, castor oil, adsorption, fipronil.

PAGES: 133
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

The purpose of this work was to carry out the chemical modification of sugarcane bagasse fibres
to be applied in the manufacture of cement composites and later, in the removal of pollutants
such as the pesticide fipronil from aqueous systems. For this, chemical treatments were
performed on the fibres, to obtain a hydrophobic surface with fatty acids, which bring a more
sustainable proposal for this research. Fibber modification was evaluated by Fourier transform
infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, energy
dispersion spectrometer and wettability study. In the study of fibres incorporated in
cementitious composites, specimens were made with bagasse without treatment and with
bagasse treated with stearic acid and castor oil and varying the fibre volume by 2, 5 and 10%,
thus evaluating the type of fibre and the amount of fibre added. The properties of the specimens
were analysed by means of apparent density, water absorption, apparent porosity, elastic
modulus, compressive strength and tenacity modulus. The material with 2% fibres modified
with stearic acid showed promising results. Regarding the study of adsorption of fipronil using
natural and modified fibres as adsorbent materials, parameters such as pH of the aqueous
solution, amount of adsorbent material, contact time/kinetics, concentration/isotherm and
temperature were evaluated. The fibre with castor oil proved to be a good sorbent of the fipronil
molecule in aqueous medium. For my part, the incorporation of 5% of the fibres adsorbed with
fipronil in cementitious composites was studied. The specimens prepared with the fibres sorbed
with the pesticide achieved performance equal or superior to the specimen with 5% of fibres
without fipronil, demonstrating that these fibres, used for the removal of the pollutant, are alsoa good alternative for the manufacture of composites. , thus avoiding the need to discard the
material after it has been used to remove the pesticide.

BANKING MEMBERS:
Externa ao Programa - 435086 - HONORIA DE FATIMA GORGULHO
Interno - 1872495 - KEYLLER BASTOS BORGES
Externa à Instituição - LEANDRA DE OLIVEIRA CRUZ DA SILVA - IFSUDESTEMG
Externa ao Programa - 1954071 - MARIA CRISTINA SILVA
Externo à Instituição - PAULO HENRIQUE RIBEIRO BORGES - CEFET/MG
Presidente - 1691537 - TULIO HALLAK PANZERA