Blendas biodegradáveis de poli(3-hidroxibutirato)/poli(e-caprolactona): obtenção e estudo da miscibilidade

Due to its biodegradability, poly(3-hydroxybutyrate) P(3-HB) has attracted much attention in the environmental sector. However, some characteristics of this polymer, such as high crystallinity, poor processability and high brittleness, have lead several research groups to study polymeric blends in order to modify P(3-HB) properties. Poly(epsilon-caprolactone) (PCL) is a synthetic polyester which is completely degraded after about one year when buried in soil. In general, it acts as a polymeric plasticizer lowering the elastic modulus and enhancing the processability of the blend. Blends of two biodegradable polymers, P(3-HB) and PCL have been prepared by casting in different compositions. Miscibility, thermal behavior and morphology of these blends were studied using modulated differential scanning calorimetry (MDSC), scanning electron microscopy (SEM) and polarizing light microscopy (PLM). The two glass transition temperatures, detected by MDSC, suggest the immiscibility of the system. Phase separation was confirmed by PLM.