Benefits of Disposing Polyhydroxybutyrate-Co-Hydroxyvalerate (PHBV) Blends in Soil, as Alternative for Low Density Polyethylene

Abstract

The use of synthetic plastics generates environmental impacts due to their low biodegradability and inadequate disposal. One of the alternatives to minimize this problem is the use of biodegradable polymers and/or the production of blends with desired industrial and eco-friendly characteristics. The biodegradation of PHBV (Poly (Hydroxybutyrate-co-Hydroxyvalerate)), LDPE (Low Density Polyethylene) and LDPE / PHBV (70/30) blends in soil column was evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), and mass loss. Through SEM it was possible to observe micro morphological changes on the surface of the PHBV and the blends, in accordance with the mass loss variation. PHBV samples showed a reduction of 43.9 % and the blend had a reduction of 15.7 %, during their biodegradation process. FTIR analysis revealed that the crystallinity of the polymeric materials changed, suggesting the biodegradation of these films. Soil samples were characterized by determination of pH, organic matter (%), moisture (%), and CFU of the microbial community. The blend was susceptible to soil microbial activity, with significant changes in its micro morphology. The used 70/30 ratio (LDPE/ PHBV) showed susceptibility to soil microorganisms, favoring the increase of its microbial community. The use of polymeric blends also favors the reduction of the amount of polymers present in the environment because some of them are biodegradable.