Banca de QUALIFICAÇÃO: JOHN ISAAC OSARO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : JOHN ISAAC OSARO
Data: 16/03/2026
HORA: 10:15
LOCAL: Sala 406 do Bloco B do Campus de Santo André da Universidade Federal do ABC
TÍTULO:

Modification of ethylene-propylene-diene monomer through in-situ polymerization of nitrogenated monomers in supercritical carbon dioxide

PÁGINAS: 20
RESUMO:

Supercritical carbon dioxide (scCO2) is a solvent that has called attention for being nontoxic, non-flammable, recyclable, easily removable from the final product and a feasible substitute for common organic solvents. Its diffusivity similar to gases and density similar to liquids allows it to swell polymers and be a vehicle for reactants for their modification. This works aims to explore the routes and conditions of the modification of different ethylene-propylene-diene monomer (a polymeric monomer), and an analogue without double bond for comparison, through in-situ polymerization of two nitrogenated monomers, which was done in two steps, impregnation and polymerization. The route of the in-situ polymerization was evaluated fixing the conditions of the impregnation step at {25 MPa; 35°C} and varying the pressures (25 MPa and 0.1 MPa) and times (4 and 24 h) of the polymerization step at 80 °C and the transition from the first to the second step (without or with fast decompression, without or with re-pressurization of the system). The study of the best condition for the process was done varying the conditions of the impregnation step from 35 to 55 °C and from 10 to 25 MPa. After the process, unreacted and ungrafted molecules were extracted and the % grafting was determined gravimetrically. FTIR analyses were used to follow the progress of each step of the process and to characterize the final samples and it confirmed that the polymers were modified. The solubility of the monomers in scCO2 were also evaluated. The % grafting ranged from <1 to 30 % and were shown to be higher for polymers containing double bonds. It is shown that polymer composition, speed of decompression and media of polymerization influence the extent of grafting. Moreover, increasing the density of the impregnation step was shown to also increase the % grafting, indication that it increases the impregnation of the monomer at the polymeric matrix, probably due to the increase of the monomer solubility at the media, which also was shown to be positively affected by the CO2 density. It was shown that using scCO2 as swelling media for impregnation is an efficient strategy for the modification of ethylene-propylene-diene monomers, which contributes to the development of new functional materials.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 2352281 - LIGIA PASSOS MAIA OBI
Membro Titular - Examinador(a) Interno ao Programa - 1085298 - JULIANA MARTIN DO PRADO
Membro Titular - Examinador(a) Externo ao Programa - 1850090 - ANNE CRISTINE CHINELLATO
Membro Suplente - Examinador(a) Externo ao Programa - 1761120 - DANILO JUSTINO CARASTAN