Plasma surface grafting of PEEK for enhanced mechanical properties in PAKD/PEBA double-layer medical catheters

The growing demand for advanced medical catheters in minimally invasive surgery underscores the importance of optimizing catheter mechanical properties. Although existing studies have explored various multilayer catheters made from different materials and composite designs, research on poly ether ether ketone (PEEK)-based double-layer catheters remains limited. This work developed a PAKD/PEBA double-layer medical catheter utilizing a combination of plasma surface modification and multi-step grafting. The approach enhanced the interlayer peel strength from 0 N to 6.78 N, meeting the bonding requirements for medical catheters. Moreover, compared to a single-layer PEEK catheter with the same dimensions, the bending stiffness of the PAKD/PEBA double-layer catheter was reduced by 39.65% and the torsional stiffness by 34.14%, resulting in improved flexibility and torsional resistance.