Polymerization-like grafting of thermoplastic polyurethane by microwave plasma treatment

In this study, the low temperature microwave plasma was used to activate the surface of thermoplastic polyurethane (TPU). Sequentially, grafting with acrylic acid (AA) can be achieved. To immobilize collagen, the coupling reactions between carboxylic group of AA and amino group of protein formed by the assistance of 1-ethyl-3-(-dimethylaminopropyl) carbodiimide. Under controlled plasma parameters, hydrophilic property can be improved for grafted and immobilized TPU. The optimized plasma parameter was using 40 W oxygen plasma under a vacuum of 0.1 Torr for 30 s. Collagen was immobilized successfully on the AA-grafted TPU and confirmed by the Coomassie brilliant blue G test.