A simple and efficient technique to prepare aromatic polyhydroxibutirate/polybutylene adipate terephthalate blends

Polyhydroxybutyrate (PHB) is a biodegradable polymer, and preparation of a blend with another biodegradable polymer, polybutylene adipate terephthalate or Ecoflex® (ECO) is described. Some works in the previous literature show the possibility of preparing blends involving both. The techniques normally used previously described normally an extrusion process or even mixers that require high investment such as HAAKE Rheomix, for example. The main contribution is use of an original and simple technique, especially with low cost in relation to the earlier works described elsewhere. Obtaining solutions of both polymers and studies of miscible mixtures is the basis of the blending preparation process. The mass percentage ratios used to prepare the blends were 5, 10 and 20% ECO in PHB. Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and dynamic-mechanical thermal analysis (DMA) were used for characterization of blends. It was observed an increase in the flexibility of blends when compared to PHB as pointed out in the recent literature. By using SEM, it was concluded that there is interaction between the phases present in the blend and this interaction benefits miscibility. The results obtained by the DMA analyses in flexion modulus and by the differential scanning calorimetry (DSC) curves showed miscibility is dependent on ECO concentration as expected.