Effects of an Aromatic Fluoro‐Diol and Polycaprolactone on the Properties of the Resultant Polyurethanes

In this study, we used 4,4′‐diphenylmethane diisocyanate (MDI), polycaprolactone diol (PCL), and 4‐(1,1,1,3,3,3‐hexafluoro‐2‐(4‐hydroxyphenyl)propan‐2‐yl)phenol (HFP) to synthesize novel biodegradable F‐containing polyurethanes (HFP/PUs). Among which PCL is a biodegradable soft segment and HFP is a fluoro chain extender. According to FT‐IR and XPS spectroscopies, there is a strong hydrogen bonding interaction between F‐ (in CF3) and –NH groups in the HFP/PUs. For the HFP/PUs, the initial decomposition temperature, glass transition temperature (Tg), dynamic Tg, tensile strength, Young's modulus, and chemical resistance increase with the content of HFP unit or hard segment. This behavior is due to the increase of rigid hard segment and the interaction between CF3 and ‐NH groups in the HFP/PUs. On the contrary, HFP/PU containing more HFP has lower value of elongation at break. In addition, the AFM images show that the HFP/PU containing higher HFP content exhibits more humpy protrusions and is more rugged. The results of in vitro erythrocyte adhesion tests indicate that the average quantity of erythrocytes adhered on HFP/PU surface decreases with increasing HFP or fluorine content. So fluorine element with low surface free energy is helpful for HFP/PUs to be used as biomedical materials.