Synthesis and surface mobility of segmented polyurethanes with fluorinated side chains attached to hard blocks

Abstract

Novel polyurethanes with fluorinated side chains attached to hard blocks were synthesized and characterized by NMR, mass spectroscopy, DSC and gel permeation chromatography (GPC). A unique chain extender, 3-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoro-octyloxy)-propane-1,2-diol (PFOPDOL) was prepared from 3-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoro-octyloxymethyl)-oxirane (PDFOMO) by reacting it with diluted perchloric acid. Poly(ether urethane)s and poly(carbonate urethane)s containing various amounts of the chain extender with fluorinated side chains were then synthesized using methylenebis(phenylene isocyanate) (MDI), polytetramethyleneoxide (PTMO), poly(1,6-hexyl-1,5-pentylcarbonate) diol (PHPCD), 1,4-butandiol (BDO) and PFOPDOL. Mechanical properties of the polyurethanes were characterized by Instron. Surface properties were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. Results from GPC and Instron studies indicated that fluorinated polyurethanes with high molecular weights and good mechanical properties were obtained. Results from XPS and contact angle studies indicated that the surface of fluorinated polyurethanes were very nonpolar due to migration of fluorinated side chains to the surface.