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 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
A series of telechelic oligo[(R,S)‐3‐hydroxybutyrate]‐diols (PHB‐diols) was synthesized from ethyl (R,S)‐3‐hydroxybutyrate (ethyl (HB)) and four different aliphatic diols, namely, 1,4‐butanediol, 1,6‐hexanediol, 1,8‐octanediol and 1,10‐decanediol by transesterification and condensation in bulk. The structures of the synthesized oligomers were confirmed by 1H NMR spectroscopy and MALDI‐TOF mass spectroscopy. The use of 1,4‐butanediol results in an oligoester with hydroxyl functionality of approximately 2. In the case of the higher aliphatic diols, the number average functionalities were found to be lower than 2. These differences were ascribed to side reactions which occur during polymerization, yielding unreactive end groups. Other novel families of biodegradable poly(ester‐urethane)s were synthesized either from PHB‐diol alone, or PHB‐diol mixed with poly(ε‐caprolactone)‐diol (PCL‐diol), poly(butylene adipate)‐diol (PBA‐diol) or poly(diethylene glycol adipate)‐diol (PDEGA‐diol). In each case, 1,6‐hexamethylene diisocyanate was used as a nontoxic connecting agent. The homopolymers prepared from PCL‐diol, PBA‐diol and PDEGA‐diol were also synthesized for the sake of comparison. All the prepared copolymers possess high molecular weight with glass transition temperature (Tg) values varying from –54 to –23°C. Some of the prepared copoly(ester‐urethane)s are partially crystalline with melting temperatures (Tm's) varying from 37 to 56°C. 相似文献
Described is a robust platform for the synthesis of a large diversity of novel functional CO2‐sourced polymers by exploiting the regiocontrolled ring‐opening of α‐alkylidene carbonates by various nucleophiles. The reactivity of α‐alkylidene carbonates is dictated by the exocyclic olefinic group. The polyaddition of CO2‐sourced bis(α‐alkylidene carbonate)s (bis‐αCCs) with primary and secondary diamines provides novel regioregular functional poly(urethane)s. The reactivity of bis‐αCCs is also exploited for producing new poly(β‐oxo‐carbonate)s by organocatalyzed polyaddition with a diol. This synthesis platform provides new functional variants of world‐class leading polymer families (polyurethanes, polycarbonates) and valorizes CO2 as a chemical feedstock. 相似文献
A novel degradable poly(alkylene carbonate anhydride) (PACA) was synthesized by the melt polycondensation reaction of the corresponding mixed anhydrides of the dicarboxylic acid derived from oligo(tetramethylene carbonate)diol (OTMCD) and oligo(hexamethylene carbonate)diol (OHMCD). The polymer's structure was confirmed by IR and 1H NMR spectroscopy. DSC analysis showed PACA had a low Tg (< –30°C). In vitro degradation tests indicated that the degradation rate of poly(alkylene carbonate) was more controlled with the incorporation of anhydride groups. 相似文献
A series of novel polyurethanes (PUs) containing zwitterionic sulfobetaine groups were synthesized from polycarbonatediol with alkyne groups and 3-((2-azidoethyl)dimethylammonio)propane-1-sulfonate using the copper-catalyzed 1,3-dipolar cycloaddition (click) reaction. All the polyurethanes were fully characterized by 1H NMR, Fourier transform infrared spectrometer, gel permeation chromatography, and elemental analysis; the thermal properties were investigated by thermogravimetric analysis and differential scanning calorimetry. It has been proved that the thermal stability of zwitterionic sulfobetaine functionalized polyurethanes were greater than the starting alkyne-containing polyurethane. Protein adsorption was measured and it was indicated that PUs with zwitterionic sulfobetain structure are a kind of biocompatible materials with a better anti-protein fouling property compared to the corresponding alkyne-containing polyurethanes. 相似文献
In the current study, the novel fluorinated polyurethanes (FPUs) that contained the gemini branched fluoroether side groups on the hard segments were developed. In brief, to obtain these FPUs, a new class of fluorinated gemini diol with double‐branched fluoroether side groups was first synthesized and characterized by using Fourier transform infrared spectroscopy, nuclear magnetic resonance, and mass spectrometry. Subsequently, a series of FPUs were designed and prepared by using hexamethylene diisocyanate, poly (tetramethylene oxide glycol), 1,4‐butanediol, and fluorinated gemini diol. Analysis of the FPUs' surface properties from contact angle analysis indicated that the water contact angle increased from 81° to more than 120° when the content of fluorinated gemini diol was increased. Differential scanning calorimetry results revealed that introduction of fluorinated gemini dio decreased the Tg of FPUs, causing a better phase separation. Results from thermogravimetric analysis studies indicated the thermal stability of FPUs was improved. Scanning electron microscopy and energy dispersive X‐ray spectroscopy revealed that fluoroether groups migrate to and enrich on the outmost surface of FPUs. 相似文献
Three new amphiphilic phospholipid diols containing hydrophilic phosphatidylcholine analogues in the main chains and hydrophobic octadecyl, hexadecyl or dodecyl alkyl groups in the side chains were synthesized. The typical phospholipid diol based on an octadecyl group was further reacted with diisocyanates such as hexamethylene diisocyanate (HDI), 2,4-tolylene diisocyanate (TDI) and 4,4′-methylenediphenyl diisocyanate (MDI), respectively. Preliminary studies suggest that polyurethane based on MDI shows a viscosity behavior similar to common polyelectrolytes and exhibits a therm decomposition peak at 244°C due to the phospholipid moiety and a melting point at 218°C. 相似文献
As a contribution to the study of fire retardance in polyurethanes by phosphorus containing compounds, polyurethanes with phosphorus incorporated in the structure have been prepared and characterized. Mol ratios P atoms/urethane linkages up to 1.108 have been obtained. Preparations were carried out in three steps: (1) formation of a phosphorus containing polyol by reaction of butane diol (BD) with phenylphosphonic dichloride, (2) end capping of the polyol with methane-bis-(4-phenyl isocyanate) (MBPI) to form prepolymer and (3) reaction of prepolymer with MBPI and BD in various proportions. 相似文献
Several new polyurethanes containing cholesterol and phosphatidylcholine analogous moieties were synthesized by addition polymerization of 2-[bis(2-hydroxyethyl)methylammonio]ethyl 5-cholesten-3β-yl phosphate ( 2 ) with diisocyanates such as hexamethylene diisocyanate (HDI), 2,4-tolylene diisocyanate (TDI), 4,4′-methylenediphenyl diisocyanate (MDI) and m-xylylene diisocyanate (XDI), respectively. They were characterized by their IR and 1H NMR spectral data and elemental analyses. Preliminary studies suggest that these polyurethanes show the viscosity behavior of common polyelectrolytes. 相似文献
A novel alcohol-soluble polyorganosiloxane containing amino side groups, poly[3-(4-aminophenoxy)propylmethylsiloxane] (2), was first prepared by the reduction of nitro groups on 4-nitrophenoxypropyl side chains of poly[3-(4-nitrophenoxy)propylmethylsiloxane] (1). The reaction proceeded easily with nearly 100% conversion. The synthesized alcohol-soluble polymer 2, which has potential application as a precursor for preparing advanced functional polymers, was characterized by FTIR 1H-NMR, 13C-NMR, 29Si-NMR, VPO and GPC, respectively. 相似文献
Segmented polyurethanes with N-alkylated amides as soft blocks as prepared. Comparisons are made with both a poly(ester urethane) and a poly(ether urethane) with the same hard block; the poly(amide urethane) is more hydrolytically stable than the polyester containing material and demonstrates greater thermooxidative stability than that with the polyether moiety. The aliphatic poly(amide urethane)s remain transparent upon exposure to uv light. 相似文献
Relatively high-molecular-weight segmented polyurethanes based on methylene bis(4-phenyl-iso-cyanate), poly(propylene glycol), butane-1,4 diol, and cis-2-butene-1,4 diol have been synthesized and characterized. These unsaturated polyurethanes were successfully grafted using N-vinyl pyrrolidone as monomer and 2,2′-azobisisobutyronitrile as free-radical initiator. However, grafting experiments involving benzoyl peroxide as initiator were unsuccessful. The graft copolymers were isolated from the ungrafted polyurethane and poly(N-vinyl pyrrolidone) by selective solvent extraction. Elemental microanalysis, IR, NMR, thermogravimetric analysis, and equilibrium water sorption measurements were used to characterize the graft copolymers. 相似文献
Two series of segmented poly(ester‐urethane)s were synthesized from bacterial poly[(R)‐3‐hydroxybutyrate]‐diol (PHB‐diol), as hard segments, and either poly(ε‐caprolactone)‐diol (PCL‐diol) or poly(butylene adipate)‐diol (PBA‐diol), as soft segments, using 1,6‐hexamethylene diisocyanate as a chain extender. The hard‐segment content varied from 0 to 50 wt.‐%. These materials were characterized using 1H NMR spectroscopy and GPC. The polymers obtained were investigated calorimetrically and dielectrically. DSC showed that the Tg of either the PCL or PBA soft segments are shifted to higher temperatures with increasing PHB hard‐segment content, revealing that either the PCL or PBA are mixed with small amounts of PHB in the amorphous domains. The results also showed that the crystallization of soft or hard segments was physically constrained by the microstructure of the other crystalline phase, which results in a decrease in the degree of crystallinity of either the soft or hard segments upon increase of the other component. The dielectric spectra of poly(ester‐urethane)s, based on PCL and PHB, showed two primary relaxation processes, designated as αS and αH, which correspond to glass–rubber transitions of PCL soft and PHB hard segments, respectively. Whereas in the case of other poly(ester‐urethane)s, derived from PBA and PHB, only one relaxation process was observed, which broadens and shifts to higher temperature with increasing PHB hard‐segment content. It was concluded from these results that our investigated materials exhibit micro‐phase separation of the hard and soft segments in the amorphous domains. 相似文献