Characterization of thermoplastic based product degradation by Immobilized Mycelia of Pleurotus Ostreatus

Abstract

Research was conducted to determine the degradation of Polyethylene Terephthalate (PET) and High Density Polyethylene (HDPE) plastic based on its mechanical properties and material weight as well as physical and chemical changes via scanning electron microscopy (SEM), tensile test, degradation characteristics and fourier trasnform infrared spectroscopy (FTIR). Three methods of degradation which are abiotic, biotic and the combination of abiotic and biotic degradation were applied. A natural isolate, Pleurotus ostreatus, was used as a biodegrader via entrapment of mycelia in immobilized Ca-alginate beads for biotic degradation. This fungus degraded 4.6 %, 5.72 % and 13.27 % for PET samples after 60 days of abiotic, biotic and the combination of abiotic and biotic degradation respectively. For HDPE samples, this fungus degraded 1.40 %, 2.97 % and 10.36 % after 60 days of abiotic, biotic and the combination of abiotic and biotic degradation respectively. During degradation, the tensile strength decreases, elongation at break significantly decreased while modulus of elasticity increases for both types of plastics, PET and HDPE. The percent of tensile reduction was higher during the combination of degradation for both plastics which were 5.01 % and 3.96 % for PET and HDPE respectively. The changes in the aspect is reflected in most of the properties, the intensities in the FTIR spectra increase and surface properties are changed because of the degradation occur. The combination of abiotic and biotic degradation revealed that the plastics were highly degrade compared to abiotic degradation and biotic degradation.