Banca de DEFESA: AMANDA MARTINS JORDÃO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : AMANDA MARTINS JORDÃO
DATE: 09/12/2022
TIME: 08:00
LOCAL: por participação remota
TITLE:

IMPREGNATION OF CLOVE EXTRACT (EUGENIA CARYOPHYLLUS) IN POLYCARBONATE AND POLY(L-LACTIC ACID) VIA SUPERCRITICAL CO2

PAGES: 60
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

Polymers that release natural extracts are relevant for various applications such as food packaging, wound treatment, cosmetics, and agriculture. A promising alternative to loading natural extracts into polymeric matrixes is CO2 supercritical (scCO2) impregnation since it is more sustainable than conventional impregnation processes. It allows for obtaining solvent-free products and can operate at low temperatures, thus preserving the properties of the thermosensitive compounds. The influence of processing conditions and physical-chemistry interactions between the system components is well known for the impregnation of polymer and one compound system. Although natural extract impregnation is more attractive due to its high bioactivity arising from the synergistic action of its different compounds, there is no systematic study about the influence of operational parameters and physical-chemical interactions in the impregnation of natural extracts. Therefore, the present study aims to interpret the phenomena derived from scCO2-assisted impregnation of clove extract into polycarbonate (PC) and poly(L-lactic acid) (PLLA) to optimize the multicomponent system process. A face-centered design (FCD) using 11 experiments was developed to investigate the impregnation process under different temperatures (35, 47,5, and 60ºC) and pressure (10, 20, and 30 MPa) for three hours. Impregnated extract and its composition in the polymeric matrix were determined gravimetrically and through gas chromatography (GC). For both PC and PLLA, a significant impregnation value was achieved (6,8 – 44 %). The impregnation conditions influenced the impregnated extract's composition, which differed from the crude extract and was higher in eugenol concentration. FTIR analyses permitted the evaluation of the interaction between the polymer matrix and natural extract, and DSC and SEM analyses allowed evidencing the impact of the impregnation process on the polymer microstructure. Also, the antibacterial property of impregnated films was evaluated through biological tests using Escherichia Coli (ATCC 33694) e Staphylococcus Aureus (ATCC 29213).

BANKING MEMBERS:
Presidente - Interno ao Programa - 1850090 - ANNE CRISTINE CHINELLATO
Membro Titular - Examinador(a) Externo à Instituição - PEDRO MIGUEL VIDINHA GOMES - USP
Membro Titular - Examinador(a) Externo à Instituição - BRUNO GRIGNARD
Membro Suplente - Examinador(a) Interno ao Programa - 1676364 - JULIANA MARCHI
Membro Suplente - Examinador(a) Externo ao Programa - 1544341 - WENDEL ANDRADE ALVES