Cleaner and profitable industrial technology for full recovery of metallic and non-metallic fraction of waste pharmaceutical blisters using switchable hydrophilicity solvents

Abstract

Abstract This research aims to develop a cleaner and profitable industrial technology for full recovery of metallic and non-metallic fraction of waste pharmaceutical blister packaging using switchable hydrophilicity solvents. In the developed technology, ultrasonic treatment was used to accelerate the breakage rate of adhesive bonding and molecular forces between the layers of packaging composite, eventually delaminating all layers as received (aluminum, plastic, etc.) or in the form of residues (printing ink and solidified polymer). The delamination process was conducted on six preliminary crushed types of full-size blisters) with different structure, size, and color at the temperature range of 40 °C - 80 °C. Solidified polymer was recovered in the shape of flakes from the solvent after its saturation by CO2 under cooling. Metallographic microscope, Scanning Electron Microscopy, Energy Dispersive Spectrometry, Fourier-transform infrared spectroscopy, Thermogravimetric analysis, and Differential scanning calorimetry were used to examine the materials recovered from each blister type as well as the changes in the solvent before, after CO2 addition, and CO2 removal to regenerate the solvent. The results showed that all blister packaging types had distinctive structure in terms of morphology and chemical composition. Aluminum was the main metallic element found in all types as a single or a double foil layer with average presence ∼17 wt.% and average purity 81%. At the same time, polymers Polyvinyl Chloride, Polypropylene, Polyethylene terephthalate, Polyvinylidene Chloride, and Low-density polyethylene were the main components in forming film and coating layers. The results showed that the recovered Polyvinyl Chloride and Polypropylene had good thermal stability and glass transition temperature. Lastly, the economic assessment of the developed approach was done to discuss the possibility of the new technique integration into Circular Economy system.