Banca de DEFESA: RENAN FERREIRA MENEGASSI DE SOUZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RENAN FERREIRA MENEGASSI DE SOUZA
DATA : 18/02/2020
HORA: 14:00
LOCAL: Campus Santo Andre
TÍTULO:

BIOCOMPOSITES OF THERMOPLASTIC STARCH WITH VISCOSE FIBER AND TITANIUM DIOXIDE 

 

PÁGINAS: 93
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:

In this work we used thermoplastic starch (TPS) reinforced with viscose fiber (FV) and prepared TPS / FV biocomposites and also reinforced with titanium dioxide (TiO₂) named TPS / FV / TiO₂. TiO₂ was added to act as a reinforcement and antimicrobial. TPS and TPS / FV biocomposite films with 10 to 40% by weight (% m) of FV were prepared by mechanical stirring at 80 ° C and processed by compression molding (MC) and by single screw extrusion and molding by compression (EX) to compare the influence of processes on the properties of biocomposites. TPS, VF and TPS / FV biocomposites were characterized by X-ray diffraction (XRD) analysis, infrared spectroscopy, optical microscopy, scanning electron microscopy, thermogravimetry (TGA), moisture content and absorption. , and tensile test. TiO2 and TPS / FV / TiO2 nanobiocomposites were characterized by XRD, TGA, antimicrobial activity, atomic force microscopy and tensile testing. The FV presented a smooth surface with microfibrils with a diameter of ~ 9 μm, aspect ratio of 48.08, 12.41% moisture content, crystallinity of 73.3% and consists of a mixture of cellulose I and II. The TPS samples processed by MC and EX presented humidity of 9.03 and 16.43%, crystallinity of 54.4 and 40.6%, respectively. The TiO₂ nanoparticles presented rutile structure and size of ~ 1.5 nm. The results of the tensile tests showed that the TPS / FV biocomposite processed by EX with 40% m of FV had the largest increase in maximum stress (366.85%) compared to TPS, indicating that extrusion processing was the most suitable. Increases in mechanical properties indicate that incorporation of FV into TPS resulted in a strong interaction between the matrix and the fibers. In the TPS biocomposite with 40% m of FV processed by EX which presented the highest value of maximum tension, TiO₂ nanoparticles with 3 to 5% m were incorporated. Nanobiocomposite with 5% m of TiO₂ promoted a ~ 482.25% increase in maximum stress compared to TPS, a result that has not been reported in the literature. The results of antimicrobial activity showed that TPS / FV / TiO₂ nanobiocomposite, although acting as reinforcement, did not inhibit the growth of Escherichia coli and Staphylococcus aureus bacteria. The characteristics of TPS / FV biocomposites and TPS / FV / TiO₂ nanobiocomposites compared to TPS indicate the potential for direct application in engineering.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1763443 - MARCIA APARECIDA DA SILVA SPINACE
Membro Titular - Examinador(a) Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Externo ao Programa - 1762438 - JEAN JACQUES BONVENT
Membro Suplente - Examinador(a) Externo ao Programa - 2347767 - MATHILDE JULIENNE GISELE CHAMPEAU FERREIRA
Membro Suplente - Examinador(a) Externo à Instituição - ROGERIO RAMOS DE SOUSA JUNIOR - UFABC