Banca de DEFESA: LHAIRA SOUZA BARRETO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LHAIRA SOUZA BARRETO
DATE: 24/07/2024
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:
KEY WORDS:

Biodegradation;PHB;PBAT;PET;HDPE

PAGES: 95
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The growing production and use of conventional polymers in different commercial applications represents a significant concern, both because their origins depend on non-renewable sources, fossil fuels, and because they cause environmental impacts after their disposal. The disposal of these materials in the environment has become a relevant problem, as it has generated a high amount of waste and compromised different ecosystems, the impacts on oceans and rivers being notorious in recent years, becoming a target of interest for researchers in various áreas. The aim of this study was to evaluate the biodegradation of polymers Poly(hydroxybutyrate) – PHB, poly[(butylene adipate)-co-(butylene terephthalate)],-PBAT, poly(ethylene terephthalate)–PET and high polyethylene density–HDPE in static systems, using sea water from the coastal region of the State of Pernambuco as fluid. The changes caused by microbial action in the specimens were analyzed by gravimetric tests and analysis of mechanical properties of polymers before and after exposure. The chemical composition was evaluated by Fourier transform infrared spectroscopy (FTIR). Thermal analyzes of these polymers were performed using differential scanning calorimetry (DSC) and thermogravimetric (TGA), to determine the melting temperature and crystallinity of each polymer. The results of the gravimetric tests showed that the degradation rates were higher for PHB and PBAT, which is corroborated by the microbiological tests of the systems that demonstrated that the surface of HDPE and PET are less susceptible to biofilm formation and, consequently, to biofilm formation. enzymatic action of microorganisms. Through FTIR it was observed that biodegradation for PHB occurs both in the amorphous and in the crystalline phase and for the other polymers there was no evidence of biodegradation. In the thermal analysis, no difference in crystallinity was observed, nor a significant difference in thermal stability, after exposure to the fluid under study in all periods.

COMMITTEE MEMBERS:
Externa à Instituição - ROSMARY NICHELE BRANDALISE - UCS
Externa ao Programa - 3218488 - DAYANNE DINIZ DE SOUZA - nullInterno - 2457389 - EDUARDO PADRON HERNANDEZ
Presidente - 2572606 - GLORIA MARIA VINHAS
Externo ao Programa - 3285750 - PEDRO FERREIRA DE SOUZA FILHO - null