Theoretical Solvent Recovery and Grafting Application in Xinjiang Waste PE Based on Solubility Parameters

This paper investigates the recovery of waste PE (mulch film) from Xinjiang by solvent recovery method. Under the guidance of solubility parameter theory, combined by HSPiP (version 4.1.07) experiment and HSPs library screening, xylene was selected as the most suitable solvent for recovery of PE. Subsequently, the solid–liquid method was used to graft MAH (maleic anhydride) to PE, and the optimal process conditions were obtained through orthogonal experiments, and the successful grafting of MAH to PE was verified by infrared spectroscopy. Then through XRD(X-ray diffraction) and other checks to analyze the PE before and after grafting, MAH did not change the crystal arrangement of PE, nor did it alteration the crystal type, the introduction of MAH enhanced the surface energy of PE and reduced the regularity of the PE structure. The results of DSC(Differential scanning calorimeter) showed that after MAH grafting, the nucleation site on the surface of PE increased, which could make the modified PE crystallize rapidly, so that the cold crystallization peak disappeared, and the stability was enhanced, which is of great significance for subsequent asphalt modification.