Low friction thermoplastic polyurethane coatings imparted by surface segregation of amphiphilic block copolymers

This study aims to hydrophilize thermoplastic polyurethane (TPU) surface via selective segregation of amphiphilic block copolymers from bulk TPU matrix, namely “inverted grafting-to” approach. To this end, hydrophilic poly(ethylene glycol) (PEG) polymer chain was employed in either diblock (polycaprolactone-b-poly(ethylene (PCL-b-PEG)) or triblock (poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene (PEG-b-PPO-b-PEG)) copolymer additives matrix. Greatly reduced water contact angles, as low ca. 13°, ≥90° for bare substrate proved the successful hydrophilization by approach, although degree significantly affected structure and concentration embedded copolymers. Moreover, PEG-functionalized surfaces approach displayed a reduction coefficient friction (COF) two orders magnitude. Given that is widely used material urinary catheter other medical devices, we demonstrated first promising application lubricious coating TPU-based tubes.