Eco efficient thermo ultrasonic recycling of pet for cost effective electromagnetic shielding applications

The research introduces a cost-efficient strategy for developing an electromagnetic interference shielding composite entirely derived from recycled polyethylene terephthalate (PET) serving simultaneously as matrix and filler source. Porous carbon (POC) was synthesized from waste PET and incorporated into a PET matrix at various loadings (3, 5, 8, 15, 20, and 30 wt%) through an innovative thermo-ultrasonic technique (TUT). This hybrid processing approach couple's polymer melting with ultrasonic vibrations to achieve homogeneous particle dispersion and enhanced interfacial binding. The morphological and structural features of the composites were thoroughly characterized using SEM, AFM, XRD, BET, FTIR, and Raman spectroscopy. Results verify that TUT further providing well dispersion, effectively drives polymer chain penetration into POC pores, substantially improving mechanical integrity. Electromagnetic shielding assessments performed across the X-band (8-12 GHz) reveal that the composite containing 30 wt% POC provides optimal attenuation, achieving 10-37 dB shielding efficiency, corresponding to ≥ 99.94% wave suppression for a 2 mm thickness. Furthermore, thermal conductivity measurements demonstrate a reduction to 0.72 W. m⁻¹.K⁻¹ at 30 °C (approximately 46% lower than pristine PET), confirming its dual functionality as both electromagnetic and thermal insulator. This outcome highlights TUT as a sustainable fabrication route enabling high-performance electromagnetic shielding composites.