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

Membranes of hydroxyl-terminated polybutadiene-based polyurethanes (PUs) we re prepared with different types of diisocyanates, hard segment contents an d thickness. Three effects on the molar adsorption ratio of fibrinogen to a lbumin (F/A molar ratio) of polymer surface were under investigation: the d eviation of surface from overall composition, the aggregation of hard segme nts (i.e. phase separation) and membrane thickness. The former two effects were contributed by different membrane thickness. Surface composition was q uantified 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 hyd rogen bonding index, which is the relative absorbance of the hydrogen bonde d carbonyl peak to that of free hydrogen bonded carbonyl peak. We found tha t a suitable phase separation or surface composition on these PU polymer su rface possess the lowest F/A molar ratio. (C) 1999 Elsevier Science Ltd. Al l rights reserved.