Synthesis, characterization and investigation of new multifunctional processing auxiliary materials to improve processability of polyolefins

Polyolefins such as polyethylene and polypropylene are widely used in packaging and automotive industries; however, high melt viscosity and surface defects (melt fracture, sharkskin) limit processing efficiency. Conventional fluoropolymer-based processing aids effectively eliminate these problems but raise serious environmental and health concerns due to persistent per- and polyfluoroalkyl substances (PFAS). In this study, a novel PFAS-free multifunctional processing aid was developed by functionalizing hexagonal boron nitride (hBN) with 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO) via urea and boric acid pyrolysis followed by solvothermal grafting. The synthesized hBN/BHT-CHO hybrid combines the lubricating and thermally conductive properties of hBN with the antioxidant activity of the hindered phenol derivative. Successful functionalization was confirmed by FTIR (new peaks at 3400 cm⁻¹ (O-H) and 1710 cm⁻¹ (C=O), TGA (onset of organic degradation at ~200 °C), SEM (coated platelets 1–5 μm), and XRD (preserved hBN crystallinity). The developed hybrid offers dual functionality; flow enhancement and oxidative stabilization; making it a sustainable alternative for high speed extrusion of polyolefin films and pipes.