Comparative study of surface modification of fluorinated and non-fluorinated polymers using SDBD air plasma

This study investigates the surface modification of Fluorinated Polytetrafluoroethylene PTFE and Non-Fluorinated polyethylene PE, two widely used polymers with inherent hydrophobicity and poor adhesion, using atmospheric air plasma generated by Surface Dielectric Barrier Discharge (SDBD). Through comprehensive analysis including ATR-FTIR spectroscopy, contact angle measurements, surface energy determination and lap shear adhesion testing, it demonstrated significant enhancement of interfacial bonding properties in both polymers. The lap shear tests revealed a remarkable improvement in adhesion strength, with PTFE showing superior performance compared to PE after plasma treatment. This difference is attributed to more effective surface defluorination and subsequent functional group incorporation in PTFE, as confirmed by ATR-FTIR analysis. The creation of polar functional groups along with increased surface roughness, as observed by AFM, contributed to enhanced mechanical interlocking. These findings highlight the exceptional potential of SDBD air plasma treatment for PTFE surface modification, particularly in applications requiring strong interfacial bonding, while still demonstrating significant improvements for PE. Comparative analysis reveals distinct modification mechanisms for PE and PTFE: PE primarily undergoes oxidation, while PTFE relies on defluorination and roughening. The findings highlight SDBD plasma's versatility in tailoring polymer surfaces for applications in biomedical devices, coatings, and composites, offering a cost-effective and eco-friendly alternative to conventional methods. The results provide valuable insights for optimizing plasma parameters to maximize adhesion in fluorinated versus non-fluorinated polymer systems.