Depolymerization of Polyethylene Terephthalate (PET) from 3D Printed Waste via Thermal and Alkaline Hydrolysis

Additive manufacturing sector is an exponentially growing industry which contributing high usage of plastic which has also seen an increase of waste generation throughout the world. Polyethylene Terephthalate (PET) is one of the widely used polymer as 3D printing filament materials. The time taken for the polymer to degrades naturally could not catch up with the number of plastics productions annually. Thus, experts emphasize that there should be other alternative methods to degrade polymers. This study aims to investigate the degradation rate of PET via kinetic study of thermal hydrolytic and alkaline hydrolysis treatment. 3D printed waste from PET were crushed into fragment size and undergone thermal hydrolytic and alkaline hydrolysis at different reaction time and PET content. The degradation rate for both thermal and alkaline hydrolysis showed increment as prolong reaction time. TPA yield follow the same trend of PET degradation. Meanwhile, higher PET content has reduced the degradation rate of PET. FTIR analysis proved the formation of TPA after the hydrolysis process has took placed with the formation of O-H and C-H which corresponding to the formation of carboxylic
acid and ethylene glycol in the TPA. The results indicate that PET degradation can occur at low cost and on this basis, it is recommended that environmental organizations attempt other methods to degrade polymers.