Synthesis and characterization of X-ray opaque polycarbonate urethane: Effect of a dihalogenated chain extender on radiopacity and hemocompatibility

Abstract

An inherently radiopaque poly(carbonate urethane) containing fluorine and iodine atoms in the polymer chain was synthesized and characterized. Radiopaque polyurethane was synthesized from 1,6-diisocyanatohexane (HDI), poly (hexamethylene carbonate)diol (PHCD) and a newly synthesized chain extender having fluorine and iodine in the molecule, namely, 4,4'-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)bis(2,6-diiodophenol) (IBAF). IBAF monomer imparted radiopacity and improved the hemocompatibility of the resultant polymer. For comparative evaluation, polyurethanes (PU) were synthesized by reacting monomers HDI and PHCD without any chain extender and also by reacting HDI and PHCD along with noniodinated, but fluorine containing, version of the above chain extender, namely, 4,4'-(Hexafluoroisopropylidene) diphenol (BAF). Chain extended PUs showed improved mechanical and thermal properties, and hemocompatibility compared to the nonchain extended PU. Radiopacity measurements by fluoroscopy showed that IBAF incorporated PU of 200 µm thickness had radiopacity equivalent to that of 25% barium sulfate filled noniodinated PU of same thickness and to that of 0.6-mm thick aluminum wedge. In vivo imaging using a rabbit cadaver model showed clearly distinguishable image of IBAF incorporated PU sample. All the PU materials were noncytotoxic to L929 mouse fibroblast cells. Preliminary results obtained from blood-material interaction studies showed that incorporation of fluorinated chain extenders in the PUs resulted in significant reduction in the adhesion of white blood cells onto the PU material surface and also resulted in prolonged partial thromboplastin time. Results suggest that incorporation of fluorine and iodine containing chain extenders would lead to the development PU with improved hemocompatibility and radiopacity.

Synthesis and surface properties of novel fluorinated polyurethane base on F‐containing chain extender

“…FTIR spectra of PU and FPU were shown in Figure B. Both PU and FPU show absorption peaks of 3331 cm −1 because of N─H stretching of secondary amide, 2936 to 2862 cm −1 assigned to ─CH stretching vibration, 1707 cm −1 owing to urethane carbonyl, 1537 cm −1 resulted from interaction between ─NH bending of secondary amide, 1240 cm −1 from ─C─O─C stretching in O═C─O─C─, and 1113 cm −1 attributed to ─C─O─C─ stretching vibration . In addition, FPU being containing CF 2 and CF 3 , 1202 cm −1 stretching vibration, 697 and 656 cm −1 in the fingerprint region peak from combination of rocking and wagging vibration of C─F are observed in FPU's FTIR spectrum .…”

Effect of novel aliphatic fluoro‐diol content on synthesis and properties of waterborne polyurethanes

“…Compared with PCUs without chain extender, PUs synthesized using chain extenders have greater thermomechanical stability, which was demonstrated by the reduction of platelet adhesion and activation. This indicates the potential use of FPCU and IFPCU for manufacturing biomedical products . Tang et al .…”

“…Moreover, PUs have impressive physical properties and blood compatibility when they come into contact with human blood . Several studies have applied fluorocarbon chains in the synthesis of PUs for biomedical use . For example, Li et al .…”

Synthesis and characterization of non-invasively traceable poly(ether urethane)s for biomedical applications

“…Iodine has been the atom of choice for imparting radiopacity since it has been extensively employed as a contrast agent without any side effects and higher electron density [9][10][11][12][13][14][15][16]. However, most of the reported attempts to impart radiopacity to polyurethanes either involve the usage of halogenated derivatives of BPA, which is known to possess estrogenic activities [12,[17][18][19][20], or the use of aromatic isocyanate which could result in the release of toxic aromatic di-amines during degradation [10,12,14,16,[20][21][22][23]. So, it is desirable to synthesize biocompatible polyurethanes from less toxic intermediates to avoid potentially releasing harmful products.…”