title: Effect of soft segment length on properties of fluorinated polyurethanes.
abstract: The effects of soft segment length on the variations in morphology, surface composition, and hydrophilicity have been studied in fluorinated polyurethanes (FPUs) and correlated with their preliminary blood compatibility as evidenced by in vitro platelet adhesion experiments. The fluorinated polyurethanes were obtained using hexamethylene diisocyanate (HDI) and chain extender of 2,2,3,3-tetrafluoro-1,4-butanediol (TF) as the hard segment as well as various soft segments-polytetramethyl oxides (PTMO) with molecular weights of 650, 1000, 1400, and 2000. The increased phase separation in hard-segment domains with lengthening soft segment was observed by FT-IR, which is believed to result in enhanced strength of hydrogen bonds and good hard-segment order arrangement. Thin-film XRD results indicate at least three lateral distances existing between adjacent hard segments in the crystallized hard segment. Their distribution depends strongly on the length of soft segment. Lengthening soft segment promotes the formation of dense arrangement of crystallized hard segments. Compared with the effect of phase separation, surface composition was found to exert a major influence on the preliminary blood compatibility of fluorinated polyurethanes. Increasing fluorine content by decreasing soft segment length promotes reduction in platelet adhesion and activation on polyurethane surfaces.
authors.affiliation: Department of Applied Chemistry, Fooyin University, Kaohsiung, 831 Taiwan, ROC. sc112@mail.fy.edu.tw
authors.forename: Li-Fen
authors.initials: LF
authors.lastname: Wang
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Wei
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials; D001792:Blood Platelets / Q000187:drug effects*; D002072:Butylene Glycols / Q000737:chemistry; D003485:Cyanates / Q000737:chemistry; D005466:Fluorocarbons / Q000138:chemical synthesis* / Q000494:pharmacology; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D017953:Isocyanates; D008422:Materials Testing; D008970:Molecular Weight; D010087:Oxides / Q000737:chemistry; D010973:Platelet Adhesiveness / Q000187:drug effects*; D011140:Polyurethanes / Q000138:chemical synthesis* / Q000494:pharmacology; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D002072:Butylene Glycols; D003485:Cyanates; D005466:Fluorocarbons; D017953:Isocyanates; D010087:Oxides; D011140:Polyurethanes; C015262:1,6-hexamethylene diisocyanate