Influence of injection time and in vitro degradation in the mechanical, morphological and thermal properties of poly (3-hydroxybutyrate)

ABSTRACT

PHB is a biodegradable bioresorbable polymer from natural and renewable sources and is compatible for applications in both the pharmaceutical and biomedical industries. The present study aims to evaluate the influence of injection time and in vitro degradation time on the mechanical, morphological and thermal properties of Poly (3-hydroxybutyrate) (PHB). For this, tensile and impact specimens with different injection times were injected, subjected to different degradation times and subjected to the following characterizations: differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, traction, polarized optical microscopy, field emission gun (FEG), impact and hardness. As the injection time was extended and the degradation time was advanced, the following changes were observed: up to 18.9% increase in crystallinity; principle of thermal degradation; reduction in maximum tension of up to 12.8%; evidence of hydrolytic degradation, up to 29.9% increase in impact resistance and an increase of 3.5% in hardness. Thus, it was concluded that different injection times combined with in vitro degradation influenced the final PHB properties.

Keywords
Poly (3-hydroxybutyrate); In vitro degradation; Injection Molding; Injection time