Microphase separated structure and protein adsorption of polyurethanes with butadiene soft segment

Membranes of hydroxyl-terminated polybutadiene-based polyurethanes (PUs) were prepared with different types of diisocyanates, hard segment contents and thickness. Three effects on the molar adsorption ratio of fibrinogen to albumin (F/A molar ratio) of polymer surface were under investigation: the deviation of surface from overall composition, the aggregation of hard segments (i.e. phase separation) and membrane thickness. The former two effects were contributed by different membrane thickness. Surface composition was quantified by the absorbance ratio of carbonyl group to butadiene group (CO/CC ratio) on FTIR–ATR spectra. While phase separation is expressed by hydrogen bonding index, which is the relative absorbance of the hydrogen bonded carbonyl peak to that of free hydrogen bonded carbonyl peak. We found that a suitable phase separation or surface composition on these PU polymer surface possess the lowest F/A molar ratio.