Fluorinated polyurethanes, 1. Synthesis and characterization of fluorine‐containing segmented poly(urethane‐urea)s

To produce high performance antithrombus elastomers, a series of new fluorine‐containing segmented poly(urethane‐urea)s was synthesized from 2,2,3,3,4,4,5,5‐octafluorohexamethylene diisocyanate (1) and α‐hydro‐ω‐hydroxypoly(oxyalkylene)s (5a, b and 6) or fluorinated dioxa‐1,10‐decanediols (3 and 4) (as the soft segments) via the prepolymers (7) which subsequently were reacted with various diamines including a fluorinated aliphatic diamine (2) as chain‐extenders. High‐molecular‐weight polymers were obtained in high yields with 5a and nonfluorinated diamines. Spectroscopic analysis of the prepolymers and the chain‐extended polymers indicated their structures to be highly ordered. Stress‐strain curves of films cast from a DMF solution indicated the polymers to be typical elastomers with tensile strength as much as 600–700 kg/cm2.