In this work, we synthesized two MDI-based polyurethanes, including a poly(ether)urethane (PEU) and a poly(carbonate)urethane (PCU), by using different soft segments, poly(tetramethylene oxide) and poly(hexyl, ethyl)carbonate diol (M approximately 2,000). We demonstrated that, in addition to the enhanced biostability of PCU over PEU, the biological performances of PCU in vitro were also improved in general. These included, better cellular attachment and proliferation, less platelet activation, as well as reduced monocyte activation. The unusual wide-ranging enhancement in biocompatibility for PCU was believed to be related to the larger micro-phase separation in PCU (approximately 25 nm) that caused distinct protein adsorption on the surface. The total number of adherent monocytes (nonactivated and activated) on the bare sample surfaces, albumin pre-adsorbed sample surfaces, and fibrinogen pre-adsorbed sample surfaces. 相似文献
Surface modification of segmented poly(ether urethane) (SPEU) by graft copolymerization with N,N′-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium (DMMSA), a zwitterionic sulfobetaine structure, was conducted. A simple two-step procedure for grafting of DMMSA onto the surface of SPEU film was used. The surface was first treated with ozone to introduce active hydroperoxide groups. The active surface was then exposed to the DMMSA solution in the sealed tube. Grafted SPEU film was characterized by ATR–FTIR, XPS and contact angle measurement. ATR–FTIR and XPS investigations confirmed the graft copolymerization. The monomer concentration, copolymerization temperature and time were varied to maximize the efficiency of DMMSA grafting. The equilibrium water content (EWC) and contact angle measurements showed that the hydrophilicity of the film had been greatly improved. The blood compatibility of the grafted films was evaluated by platelet adhesion in platelet rich plasma (PRP), deposits in blood control and protein adsorption in bovine fibrinogen using SPEU film as the control. No platelet adhesion and no thrombus were observed for the grafted films incubated in PRP for 300 min and in blood for 120 min, respectively. The protein adsorption was reduced on the grafted films after incubation in bovine fibrinogen for 120 min. These results proved that improved blood compatibility was obtained by grafting this new zwitterionic sulfobetaine structure monomer onto SPEU film. 相似文献
Summary: In this article, we designed and synthesized novel segmented poly(carbonate urethane)s containing both hydrophobic fluorinated alkyl group and hydrophilic phosphatidylcholine polar head groups on the side chain. The contact angle measurement, XPS, together with ATR‐IR investigation indicated a reversible overturn of the phosphatidylcholine groups with the movement of the hydrophobic fluorinated alkyl groups when the samples were treated in dry air or water. The change in environment from air to water induced a reorganization of the surface in order to minimize the interfacial free energy, resulting in a macroscopic change of surface wettability. The good environmental responsiveness of such biomembrane‐mimicking films may find successful applications as biomaterials.
Environmentally responsive surface using FPCPCU50 as an example; FPCPCU50 coated on aligned carbon nanotube film and dried in vacuum at 50 °C for 7 h and sample c treated in hot water at 80 °C for 1 h. 相似文献
In this article, we report the synthesis and properties of novel segmented polyurethanes containing alkyl phosphatidylcholine side groups. Alkyl phosphatidylcholine groups were attached to the hard blocks of the polyurethanes. A novel diol, 9-(2-hydroxy-1-hydroxymethyl-1-methyl-ethylcarbamoyl)-nonyl-phosphatidylcholine (HDEAPC), was synthesized and characterized by FTIR, 1H-NMR and mass spectroscopy. Two types of polyurethanes, poly(ether urethane)s and poly(carbonate urethane)s, containing alkyl phosphatidylcholine side groups were synthesized using methylenebis(phenylene isocyanate) (MDI), polytetramethyleneoxide (PTMO), poly(1,6-hexyl-1,5-pentylcarbonate) diol (PHPCD), 1,4-butanediol (BDO) and HDEAPC. The obtained phosphatidylcholine polyurethanes had relatively high molecular weights and good mechanical strength, as characterized by GPC and Instron. XPS and contact angle studies revealed that there was enrichment of alkyl phosphatidylcholine side groups near the surface of the polyurethanes. Biocompatibility was evaluated by protein adsorption using conventional polyurethanes as references. The surface of phosphatidylcholine poly(carbonate urethane)s effectively suppressed protein adsorption. 相似文献
Poly(ether urethane)s as biomaterials display certain favorable mechanical and biocompatibility properties. Earlier studies suggest that improved blood compatibility might be attained by introducing hydrocarbon groups at the surface. We synthesized and characterized a series of polyurethanes in which a N-2,3-dihydroxypropyl-N′-octadecyl urea chain extender (ODCE) was incorporated into the poly(tetramethylene glycol) (PTMO)/4,4′-methylenebis(phenylene isocyanate) (MDI) system. Molecular weights of the polymers varied between 40,000 and 250,000. An electron spectroscopy for chemical analysis (ESCA) study of the ODCE polyurethane surface revealed a substantially enhanced hydrocarbon concentration compared to a control PTMO/MDI/ethylene diamine (ED) polyurethane surface. Also, bulk composition analyses and ESCA data of the ODCE polymers indicated that the percentage of carbon was higher in the surface region than in the bulk. Thus, the ODCE polymer showed a marked increase in hard-segment concentration in the surface region compared to the bulk region and to the ED polymer. 相似文献
Blends of PVC and polyurethanes with four different soft segments of molecular weight 1000 were prepared and studied by dynamic mechanical and DSC techniques. It was found that the compatibility of PVC with segmented polyurethanes was related to the mixing of PVC molecules and the soft segments of the polyurethanes. Polyester based polyurethanes are more compatible with PVC than polyether based polyurethanes. Solution cast blends of PVC with PCL-polyurethane (1/2/1) exhibit single and narrow glass transition, while the blends with PPO-polyurethane (1/2/1) are completely incompatible. The compatibility was found to decrease with increasing hard segment content for all the polyurethanes used. The methods of blend preparation may change the compatibility of PVC/PU blends through their influence on the mixing or demixing of the hard and soft segments. 相似文献
Amphiphilic segmented polyetherurethanes were prepared from methylene diphenylene diisocyanate (MDI), poly(ethylene glycol) 1500 (PEG), and a fatty acid monoglyceride as a chain extender. The polymers were not soluble in water or methanol, but dissolved readily in organic solvents. The amphiphilic properties were demonstrated as a large hysteresis in the water contact angles, exceeding 110°. The amphiphilic polymers were shown to modify the surface properties of a poly(ether urethane) (PEU) and a poly(ether urethane urea) (PEUU) when added in 1–10 wt %, presumably due to migration of the additive to the surface. The surfaces of particularly the PEU blends became highly amphiphilic, exhibiting contact angles hystereses up to 90–100°. A surface saturation effect was observed at 5% added amphiphilic polymer. A difference in the behavior of PEU and PEUU was ascribed to differences in solubility of the additive in the matrix. On long-term exposure to water the PEUU blends increased their amphiphilic behavior. 相似文献
A series of segmented polyurea urethane and polyurea block copolymers based on a hexane diisocyanate (HDI) modified aminopropyl terminated polydimethylsiloxane soft segment was synthesized. The hard segments consisted of 4,4′-methylene diphenylene diisocyanate (MDI) which was chain extended with 1,4-butanediol (BD), N-methyldiethanolamine (MDEA), or ethylene diamine. Zwitterionomers were prepared by quaternizing the tertiary amine of the MDEA extended material with γ-propane sultone. The effect of chemical structure on the extent of phase separation and physical properties was studied using a variety of techniques including thermal analysis, dynamic mechanical spectroscopy, tensile testing, and small-angle x-ray scattering. It was observed that the compatibility between the nonpolar polydimethylsiloxane soft segments and the polar urethane hard segments was improved by inserting HDI linkages into the polydimethylsiloxane soft segments. The aggregation of hard segments was enhanced by increasing hard-segment content or by the introduction of ionic functionality. The tensile strength and modulus of these materials was higher than those of polyurethanes containing soft segments based on polydimethylsiloxane and its derivatives. 相似文献
A series of polyurea urethane block polymers based on either aminopropyl-terminated polycyanoethylmethylsiloxane (PCEMS) soft segments or soft segment blends of PCEMS and polytetramethylene oxide (PTMO) were synthesized. The hard segments consisted of 4,4′-methylenediphenylene diisocyanate (MDI) chain-extended with 1,4-butanediol. The hard segment content varied from 11 to 36%, whereas the PTMO weight fraction in the soft segment blends varied from 0.1 to 0.9. The cyanoethyl side group concentration was also varied during the synthesis of the PCEMS oligomer. The morphology and properties of these polymers were studied by differential scanning calorimetry, infrared spectroscopy, dynamic mechanical and tensile testing, and small-angle x-ray scattering. These materials exhibited microphase separation of the hard and soft segments; however, attaching polar cyanoethyl side groups along the apolar siloxane chains promoted phase mixing in comparison with polydimethylsiloxane-based polyurethanes. The increased phase mixing is postulated to lead to improved interfacial adhesion and thus can account for the observed improvement in ultimate tensile properties compared with polydimethylsiloxane-based polyurethanes. Both hard segment content and cyanoethyl concentration are important factors governing the morphological and tensile properties of these polymers. 相似文献
Platelet adhesion and protein adsorption on the silicone rubber film grafted with N,N'-dimethyl-N-methacryloyloxyethyl-N-(2-carboxyethyl) ammonium (DMMCA) was studied. The grafting was carried out by means of ozone-induced method and was confirmed by ATR-FTIR and XPS investigations. The grafted films possessed relatively hydrophilic surface revealed by contact angle measurement. The blood compatibility of the grafted film was evaluated in vitro by platelet adhesion in platelet-rich plasma (PRP) and protein absorption in bovine fibrinogen (BFG) using silicone film as the reference. No substantial platelet adhesion was observed for the grafted films incubated in PRP for 60 and 180 min. The protein absorption was also significantly reduced after incubated in bovine fibrinogen for 60 min. Both the results indicated that the blood compatibility of silicone rubber was greatly improved by ozone-induced grafting of carboxybetaine zwitterionic polymer onto its surface. 相似文献
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. 相似文献