Polyurethane hydrogels

Polyurethane foam processing, 19 559 Polyurethane hydrogels, 13 739 Polyurethane industry, neopentyl glycol in, 12 672... 

Polyurethane hydrogels derived from UV curable urethane prepolymer and hydrophilic monomers were prepared and their properties were evaluated. The urethane prepolymer used in this study contained well-defined hard segments centered with a polyether-based soft segment and end-capped with methacrylate groups. The hydrophilic monomers studied were 2-hydroxyethyl methacrylate (HEMA), N-vinyl pyrrolidone, and glycerol methacrylate. Methacryloxypropyl tris(trimethysiloxy) silane (TRIS) was also used in some cases to modify properties. All compositions were UV... 

Polyurethane Hydrogel Cross-Linked Polyacrylamide Gels Cross-Linked Polyacrylic Acid Gels... 

Polyurethane hydrogels are prepared by reaction of a polyisocyanate with polyethyleneglycol. These hydrogels can swell with water and are used in medical applications, such as wound dressings. Although dialkyltin catalysts are claimed in this application, the use of organotin compounds in medical applications with potential contact with blood is questionable, and they are probably not the safest catalysts for this application. 

Coneski PN, Wynne JH. Zwitterionic polyurethane hydrogels derived from carboxybeta-ine-functionalized diols. ACS Appl Mater Interfaces 2012 4(9) 4465-9. 

Rao L, Zhou H, Li T, et al. Polyethylene glycol-containing polyurethane hydrogel coatings for improving the biocompatibility of neural electrodes. Acta Biomater July 2012 8(6) 2233 2. 

Yoo, H.J., Kim, H.D., 2008. Synthesis and properties of waterborne polyurethane hydrogels for wound healing dressings. Journal of Biomedical Materials Research Part B Applied Biomaterials 85, 326-333. 

Lin, Y, Li, G., 2014. An intermolecular quadruple hydrogen-bonding strategy to fabricate self-healing and highly deformable polyurethane hydrogels. Journal of Materials Chemistry B 2, 6878-6885. http //dx.doi.org/10.1039/C4TB00862F. 

Cell proliferation and differentiation Cell-seeded fibrons scaffold was fabricated via electtospinning/ electrospraying method, and scaffold mechanical and stmctural properties were controlled by polymer solntion pumping speed and polyurethane/hydrogel ratio. CDC cardiac differentiation was successfully achieved in scaffolds with high fiber volume fraction and small scaffold modulus at small strains. Xu et al. Mechanical/morphology/ composition... 

Figure 18.2 Controlled stem cell cardiac differentiation via mechanical and structural properties of polyurethane/hydrogel scaffolds.

More recently, Anzenbacher et al. developed a supramolecular-based sensor array for detection of complex matrices of anions [68]. The arrays were prepared by implementing colorimetric sensors in polyurethane hydrogel. The sensor elements are reported in Fig. 20, based on calyxpyrrole, and anthraquinine moieties. 

T.-E Chen, C.-M. Chiang, J. Jona, P. Joshi, and A. Ramdas, Polyurethane hydrogel drug reservoirs for use in transdermal drug delivery systems, WO Patent 1997009970 Al, 20 Mar 1997. 

Synthesis of PNIPAAm/polyurethane hydrogel with thermal activity. 

The SEM images of the PNIPAAm/polyurethane hydrogel treated fabrics (a) original cotton fabric (b) thin layer of hydrogel coated cotton fabric (c) thick layer of hydrogel coated fabric. 

Hu J, Liu B. and Liu W. (2006), Temperature sensitive poly(N-isopropylacryl-amide)/polyurethane hydrogel modified nonwoven fabrics with controlled release. AATCC International Conference Exhibition. Boston, USA. Yoshida T, Hattori K., Sawada Y, Choi Y.S. and Uryu T. (1996), Graft copolymerization of methyl methacrylate onto curdlan. Journal of Polymer Science, Part A Polymer Chemistry, 34 pp. 3053-3060. 

Liu B.H. and Hu J.L. (2006), A Study of Thermosensitive Poly(N-isopropylacrylamide) Polyurethane Hydrogel Modified Nonwoven Fabrics, The Hong Kong Polytechnic University Hong Kong. 

Polyurethane hydrogels are widely used in soft contact lenses, controlled release devices, semipermeable membranes and hydrophilic coatings (66). The properties of polyurethane hydrogels can be varied by variation of their components, such as the polyols, diisocyanate, chain extender, or cross-linker (67-69). Because of the excellent mechanical and physical properties, polyurethanes are widely used in medical applications such as coating for medical devices for preventing protein adsorption (70, 71). 

Fig. 10 Creep open symbols) and recovery (fiM symbols) curves for the poly(isopropyl lactate diol)-based polyurethane hydrogels at 37 °C when a stress of 5 Pa was applied for 60 s. Reproduced with permission from [96]...

Viscoelastic creep data can be presented by plotting the creep modulus (constant applied stress divided by total strain at a particular time) or the strain, as a function of time. Gradinaru et al. studied the creep response of thermogelling poly(isopropyl lactate diol)-based polyurethane hydrogels [96],... 

Gradinaru, L.M., Ciobanu, C., Vlad, S., Bercea, M., Popa, M. Thermoreversible poly(isopropyl lactate diol)-based polyurethane hydrogels effect of isocyanate on some physical properties. Ind. Eng. Chem. Res. 51,12344-12354 (2012)... 

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