Inducing polymer waste biodegradation using oxo-prodegradant and thermoplastic starch based additives

Polymer waste was subjected to biodegradation evaluation after compounding specimens with an oxo-prodegradant chemical (PDQ-M) and thermoplastic starch, to determine its susceptibility to degrade with time in contact with soil simulating an arid environment. The ASTM D 5988–18 test method was followed to evaluate the biodegradation extent of the materials under investigation, whilst using linear low density polyethylene (LLDPE), polycaprolactone (PCL) and TPS alongside the starch (positive control) as reference materials. The samples were also subjected to thermal characterisation using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), in addition to studying their infrared spectra (IR). It was noted that the LLPDE and the oxo-prodegradant induced polymer waste had a similar degradation extent evaluated after rigorous testing and monitoring, which was 23% after 180 days of experimental time. Furthermore, a plateau was reached for the biodegradation (%) as a function of time after some 50 days, which indicate that the additives in the samples act as a source of nutrient to sustain the biodegradation by enriching the microorganisms in the soil to produce carbon. The work in this study points towards a new method for treating polymer waste using physical blending with additives to biodegrade it with time as promising alternative for plastic waste accumulation.