Novel biocompatible waterborne polyurethane using L-lysine as an extender

Polyurethane (PU) prepolymers based on isophorone diisocyanates, dimethylolpropionic acid, and polycaprolactone were prepared and chain-extended in water using L-lysine (PUL), ethylenediamine (PU-E), and their mixture (PU-L-E) as extenders, respectively. The produced emulsion exhibited satisfactory freeze/thaw stability. Films cast from emulsions exhibited excellent mechanical properties and good antiblood coagulation character. Although the water-swelling ratio for 24 h for PU-L was higher than those of PU-L-E and PU-E, it possessed the smallest hydrolysis rate among the three samples.