Potential of industrial symbiosis of petroleum residues and recycled polyethylene

Abstract

In this work, a comparative study of the properties of polyethylene composites filled with the residue of solvent deasphalting of tar and asphaltenes isolated from it was carried out. Scanning electron microscopy analysis found that the compatibility of petroleum residue with the matrix was better than for asphaltenes. The observed effect was related to the present of petroleum resins, which have less polarity and long alkyl substituents that can improve molecular distribution asphaltenes in the nonpolar environment of polyethylene. Fourier transform infrared, thermo-gravimetric analysis, differential scanning calorimetry, and electron paramagnetic resonance methods have shown that asphaltenes play a key role in the thermal stabilization of composites. It is assumed that the radical traps in asphaltenes are free stable radicals, particles with unpaired electrons strongly delocalized on the π-system of polyaromatic molecules. Their antiradical action was associated to interactions with radicals formed during the thermal and thermo-oxidative decomposition of polyethylene result in the recombination and inhibition of further free-radical destruction. An analysis of the properties showed that the addition of a petroleum residue to the polyethylene makes it possible to maintain good mechanical properties after thermal-oxidative aging of composites. Thus, such asphaltene concentrates can be recommended as promising fillers for polyolefins in the polymer industry.