Synthesis and properties of novel fluorinated aliphatic polyurethanes with fluoro chain extenders

Abstract

Fluorinated aliphatic polyurethanes based on hexamethylene diisocyanate (HDI) and polytetramethyl oxide (PTMO) were synthesized by using 2,2,3,3,4,4,5,5‐octafluoro‐1,6‐hexanediol (OF) or 2,2,3,3‐tetrafluoro‐1,4‐ butanediol (TF) as a chain extender. The polyurethanes chainextended with 1,4‐butanediol (BD) were also prepared for comparison. The effects of the kind of chain extender and the average length of hard segments on the microstructure, thermal transition property, surface property and blood compatibility of the polyurethanes are discussed. The fluorinated polyurethanes exhibit weaker hydrogen bonding, a smaller fraction of hydrogen‐bonded carbonyls, less phase separated soft segment domains, a lower melting temperature and less heat of fusion of crystalline hard segment domains than the polyurethanes chain extended with BD. The polyurethanes extended with OF show the above mentioned effects more obviously than those with TF. The increase of the average length of hard segments also affects the properties, especially as the average length of hard segments increases from 1 to 2. The polyurethanes chain extended with OF posses more fluorocarbon chains at the surface than those chain extended with TF. The hard segment content of the surface and the fluorine/carbon atomic ratio increases as the bulk average length of hard segments increases. In vitro platelet adhesion studies indicated that the addition of fluorocarbon chains into aliphatic polyurethanes leads to a reduction in platelet adhesion and activation.

Preparation, characterization, and properties of fluorinated polyurethanes

“…In recent years, a number of the preparations of the FPUs have been reported 21–33. Some studies introduced fluorocarbon chains into PUs by hard segment, or diisocyanate to obtain new PUs.…”

Effect of hydroxyl‐terminated poly(fluoroalkyl methacrylate) main‐chain length on the microphase separation of waterborne fluorinated polyurethane

“…For instance, Wang found that the formation of stronger hydrogen bonds with an increase of the soft chain length led to an increase of the microphase separation and different thermal behaviors. Chen et al synthesized fluorinated polyurethanes with different hard‐segment lengths. Their research showed that the microphase separation, melting temperature and crystallinity in the hard segments increased with an increase of hard‐segment length.…”

Preparation and Characterization of Fluorinated Hydrophobic UV-Crosslinkable Thiol-Ene Polyurethane Coatings

“…However, the low reaction activity of the fluorinated polyol leads to the low molecular weight and poor mechanical property of the resulting products, which may restrict the wide applications of fluorinated polyurethane (FPU). Moreover, compared to other polyols, the fewer species and quantities of the fluorinated polyol further limited their use as modifying monomers for fluorinated polyurethane [14][15][16][17].…”