Banca de QUALIFICAÇÃO: ANNA RAFFAELA DE MATOS COSTA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANNA RAFFAELA DE MATOS COSTA
DATA : 06/03/2017
HORA: 09:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

PREPARATION AND CHARACTERIZATION OF POLY (β -HYDROXYBUTYPHATE) AND POLY (BUTYLENE-ADIPATE-TEREPHTHALATE) BLENDS: EFFECT OF COMPOSITION AND PROCESSING CONDITIONS

PALAVRAS-CHAVES:

polymer blends, biodegradable polymers, mechanical properties, thermal properties, PHB, PBAT.

PÁGINAS: 133
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:

The aim of the present work is to obtain materials with better characteristics and to study the effect of the composition and processing conditions on the properties of poly(β-hydroxybutyrate) (PHB) and poly(butylene-adipate-terephthalate) blends. (PBAT). PHB/PBAT blends were processed in a corrotating twin-screw extruder, and were characterized by torque rheometry, mechanical properties, and differential scanning calorimetry (DSC). The results of tensile strength and elongation at break suggest the incompatibility of the blend. The internal mixer results show that PHB degrades during processing at a significantly higher rate than PBAT, with an intermediate degradation rate in the PHB/PBAT blends. From the DSC results it can be seen that PHB and PBAT exhibit different degree of crystallinity, melt temperature and peak structure, but these characteristics are independent of the cooling rate and are the same for the pure resins and the blend. These results suggest that the components of the blend crystallize separately. The classical macrokinetic models, Pseudo-Avrami, Ozawa and Mo were used to describe the evolution of the crystallization process from the melt. The results show that none of these models could be used to predict the experimental results of crystallization kinetics for the blend with sufficient precision for applications in polymer processing. However, some models may be used for pure resins within a restricted range heating rate, temperature or conversion intervals, such as the Ozawa model for PHB at low heating rate and Mo model for PBAT.

MEMBROS DA BANCA:
Presidente - 1639676 - EDSON NORIYUKI ITO
Externo à Instituição - EDUARDO LUIS CANEDO - UFCG
Externo à Instituição - LAURA HECKER DE CARVALHO - UFCG