Polyurethanes grafted by pendent groups with different sizes and functionality.
Polyurethanes grafted by pendent alkyl chains along the backbone have been prepared and characterized by their mechanical properties and by in vitro adsorption of albumin and fibrinogen. The grafting of butyl, octyl, decyl, hexadecyl and tetratriacontyl chains on to the urethane nitrogen weakens the stress-strain properties, whereas these properties remain high when these alkyl groups are grafted on the 1,3-propanediol used as chain extender. The hexadecyl chain gives the highest values of albumin adsorption from in vitro tests. Polyurethanes prepared from a commercial diol bearing a polyoxyethylene-polyoxypropylene propylsulphonate side chain adsorb albumin and fibrinogen, the respective amounts depending on the substitution yield of the sulphonate group.