Banca de DEFESA: RENAN ROGERIO OLIVEIRA DE SOUZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RENAN ROGERIO OLIVEIRA DE SOUZA
DATE: 09/12/2022
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

EVALUATION OF THE BIODEGRADATION OF ACTIVE POLY(BUTYLENE ADIPATE COTEREPHTHALATE)(PBAT) FILMS UNDER ANAEROBIC CONDITIONS

KEY WORDS:

Biodegradable polymers; Anaerobic digestion; PBAT; Exotic Basil Essential Oil.

PAGES: 84
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The intrinsic resistance of plastics makes them extremely useful in many packaging applications, but they are also highly resistant to degradation and can persist for several millennia in the environment. The accumulation of plastic waste is a growing environmental problem and there is still no exact solution for this question. Biodegradable plastics are promising alternatives to conventional plastics, therefore, researches on biodegradable materials with properties that allow their application in various fields, such as packaging on a commercial scale, has been the focus of several researchers. Among these packages, active packages with microbial additives, such as essential oils, which act to inhibit or delay the growth of microorganisms in food stand out. However, depending on the polymer used for manufacturing, they can contribute to the accumulation in the environment. Thus, this work aims to study the anaerobic degradation, in sludge, of polymeric films of PBAT and PBAT added with exotic basil essential oil (OEM) during a period of 22 months. These films were analyzed by thermogravimetry, differential exploratory calorimetry and scanning electron microscopy. The quantification of the degradation was performed through the mass loss over time. As main results, it was observed that the mass loss, after 22 months, for PBAT and PBAT/OEM decreased by 4% and 22%, respectively, while the polyethylene that was used as standard showed no relevant variation. The greater mass loss can be suggested by the migration of the essential oil to the medium or by the fragmentation of the film at the time of removal from the system. About the microorganisms present in the sludge, it was observed that, at the beginning of the study, it had mostly only acid-producing bacteria, presenting, in 5 months, the Planktonic aeruginosa, and then, the Heterotrophic Anaerobic Bacteria reached the stationary phase. During the evaluation, the infiltration of oxygen in the proposed systems was confirmed, a circumstance which made possible the exponential growth of Heterotrophic Anaerobic Bacteria, making them prevalent in the biodigesters. The thermogravimetric analysis attested that the addition of exotic basil essential oil did not lead to changes in thermal degradation, with a degradation between 280 and 505 °C. For the additive films, during the degradation, it was verified an increase in the crystallization temperature and a decrease in the degree of crystallinity, due to the increase in the mobility of the polymeric chains caused by the addition of the essential oil. Through scanning microscopy analysis, it was possible to confirm signs of failure in the structure, both in PBAT and PBAT/OEM. The visualization of pores, after the study period, shows signs of degradation of the films. In view of the above, it is inferred that the essential oil did not delay the biodegradation process, thus making it viable to use PBAT/OEM films in active packaging, due to the antimicrobial and antioxidant characteristics of the essential oil incorporated.

COMMITTEE MEMBERS:
Interno - 2457389 - EDUARDO PADRON HERNANDEZ
Presidente - 2572606 - GLORIA MARIA VINHAS
Externa ao Programa - 2116297 - SARA HORACIO DE OLIVEIRA MACIEL - null