Characterization of wax produced from pyrolysis of recycled rLLDPE/rLDPE blends as a precursor for corrosion-resistant coatings

Post-consumer recycled polyethylene films are difficult to process mechanically because of variable composition, residual additives, and contamination. This study evaluated the production of a wax-rich fraction from recycled linear low-density polyethylene/low-density polyethylene (rLLDPE/rLDPE) by thermal pyrolysis and assessed its suitability as a precursor for coating applications. Pyrolysis at 400 °C for 45 min with a heating rate of 3 °C/min produced approximately 84 wt% pyrolysis-derived polyethyleCne wax (P.PE wax). The product was characterized by GC-MS, FTIR, elemental analysis, DSC, TGA, XRD, rheology, density, and pH measurements and compared with commercial paraffin wax (PAR) and polyethylene wax (C.PE). GC-MS showed a C9-C32 hydrocarbon distribution dominated by n-alkanes and 1-alkenes, with substantial abundance in the C20-C26 range. FTIR and XRD confirmed a long-chain aliphatic backbone and semi-crystalline polyethylene structure, while elemental analysis indicated a predominantly hydrocarbon composition. P.PE wax exhibited a melting temperature of approximately 58 °C, melting enthalpy of 121.3 J/g, density of 0.857 g/cm, and pH of 5.8. Its thermal and physical properties were generally intermediate between or comparable to those of the commercial reference waxes. These findings demonstrate that recycled rLLDPE/rLDPE can be converted into a wax product with composition and processing-relevant characteristics suitable for further evaluation in protective coating formulations.