A new radiopaque polyurethane was prepared via the blocking reaction between 4-iodoaniline and polycarbonate polyurethane with excess isocyanate groups.The development effect of modified polyurethane was characterized by X-radiography.The thermal behavior of the polymer was characterized with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).The cytotoxicity was tested by the method of thiazolyl blue (MTT) colorimetric assay using mouse fibroblast.Meanwhile

the development effect

relative molecular weight and mechanical properties of radiopaque polyurethanes with different iodine content were also studied.The results showed that the development effect of modified polyurethanes increased with the iodine content increased.It had a good radiopacity almost equivalent to that of a 2 mm thick aluminium wedge when the iodine content was 3.5 wt%.When the iodine content was less then 3.5 wt%

the number average molecular weight of which was in the molecular weight range of the usual thermoplastic polyurethane elastomer (Mn3×104)

and they also had good mechanical properties and thermal stability.Degradation characteristics as observed from the TGA remained unchanged compared the unmodified polyurethane.The cell proliferation rate (RGR) of all modified polyurethanes was more than 75%

they were all biomaterials without cytotoxicity.This study provides a sample modification way for preparing radiopaque polyurethane which is expected to have significant advantage over their non-radiopaque counterparts in many medical and related applications.