Thermo-chemical recovery of low molecular weight oligomers from polyethylene waste

This study focused on the chemical recycling of polyethylene using controlled thermo-chemical degradation. Polyethylene was degraded in a stirred, batch reactor under a nitrogen atmosphere. The reaction temperatures that were investigated ranged between 375$ sp circ$C and 421$ sp circ$C. The reaction time ranged between 20 and 50 minutes. Three major products were collected, an insoluble solid residue, a condensable wax that was volatile during the reaction, and a residual wax that was not volatile during the reaction. It was determined that above 409$ sp circ$C, 90% of the original resin weight was converted to both the volatile and residual wax. Both waxes had a final Mn of 400 to 500. Analysis revealed that the volatile wax was a mixture of straight chain hydrocarbons, with 4% of the carbon bonds unsaturated. The residual wax was a mixture of hydrocarbons, both straight and branched components. No liquid product was collected, and gaseous components did not exceed 10% of the original resin weight. It was also determined that silica alumina did not enhance degradation