Banca de DEFESA: PIETRO CARLOS GONÇALVES CONCEIÇÃO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PIETRO CARLOS GONÇALVES CONCEIÇÃO
DATE: 08/08/2023
TIME: 09:00
LOCAL: Faculdade de Farmácia
TITLE:

Characterization of extruded films based on poly (butylene succinate) (PBS) blends for use of partially degraded poly (butylene adipate-co-terephthalate) (PBAT)

KEY WORDS:

extrusion, characterization, biopolymers, reuse

PAGES: 72
BIG AREA: Ciências Agrárias
AREA: Ciência e Tecnologia de Alimentos
SUBÁREA: Tecnologia de Alimentos
SPECIALTY: Embalagens de Produtos Alimentares
SUMMARY:

Biodegradable polymers are a sustainable alternative to conventional petroleum-derived polymers. With the growing awareness of the environment, the demand for biodegradable plastics has increased considerably in recent years. However, these biodegradable materials have disadvantages in their physical and chemical properties compared to conventional polymers. After their shelf life, biodegradable polymers can undergo depolymerization, destruction or degradation of their polymer chain during storage, which makes partially degraded. This can prevent its use for many applications. The reuse of these materials that have exceeded the deadline stipulated by the manufacturer can contribute to reducing the cost of production and reducing the consumption of non-renewable sources. An alternative for recovering these partially degraded materials is by obtaining films through polymeric blends. With this, the objective of this work is to take advantage of a PBAT (Polybutylene adipate-co-terephthalate), which exceeded its useful life by approximately 100 months, by obtaining films through blends with a PBS (Polybutylene Succinate) (under normal conditions), as well as to characterize the physical, chemical and morphological properties of these films. The blends were formulated in five different proportions of PBS/PBAT – 100/0; 80/20; 70/30; 60/40; 50/50 (F1, F2, F3, F4, F5, respectively) – and the films were obtained by extrusion. The films were characterized by Fourier transform infrared analysis (FTIR-ATR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mechanical tensile test and vapor permeability of water. The result of the FTIR analysis showed that there were no significant changes in the chemical structure, except for the F3 formulation, which showed the highest absorption peak at 1700-1740 cm^-1. The XRD result demonstrates that there is a slight tendency for the crystallinity indices to decrease from F1 to F5, but no significant mass loss event was noted in the TGA analysis, except for F3 around 520°C, which is directly related to the heterogeneity of the constituents in the blend. SEM clearly shows a defective and heterogeneous structure of the F1-F5 constituents, which is also associated with limited miscibility between PBS and PBAT. The brittle and partially degraded structure of PBAT caused a decrease in the tensile strength limit and an increase in the water vapor permeability of the films. It was possible to take advantage of PBAT by blending it with PBS, and the concentrations of PBAT in the blends strongly influence the physical and chemical properties of the analyzed films. It is possible to make films through blends with a partially degraded PBAT together with PBS, in some degree of PBAT concentration in the films, which may be useful in some application depending on its respective purpose.

COMMITTEE MEMBERS:
Interna - 4725209 - CAROLINA OLIVEIRA DE SOUZA
Externa ao Programa - 1047082 - JOYCE BATISTA AZEVEDO - UFBAExterna à Instituição - SAMANTHA SERRA COSTA - UFRB