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  • 11
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 41 (1990), S. 3025-3042 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A number of miscible metal salt-polymer systems of acrylated phosphonates derived from various polyols such as glycerol, D-mannitol, D-sorbitol, pentaerythritol, and dipentaerythritol are described. The salt-monomer systems could be polymerized radically to form homogeneous transparent glassy polymers. Incorporation of heavy metal salts in polymers imparts radiopacity on otherwise radiolucent materials rendering them useful for X-ray imaging. The polymer-salt systems have been characterized with the aid of infrared spectroscopy and thermal and radiographic analyses. In these salt-polymer systems, salts are bonded to the polymers predominantly through the phosphoryl's oxygen. The results indicate that about 11 wt % of uranyl nitrate hexahydrate and 12.5 wt % of bismuth bromide impart a radiopacity equivalent to that of aluminum. The glass transition temperatures (Tg) of the salt-containing polymers are substantially higher than the salt-free polymers. The Tg values seem to depend on the chemical nature of the polymers, concentration of metal salts, and the extent of crosslinking induced through chelation. The analysis indicated complete solubility in the polymer matrices. No melting point endotherms of free salt crystals were detected. Some preliminary adhesion measurements revealed that acrylated phosphonates are excellent adhesion promoters for hard tissues.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 40 (1990), S. 835-843 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The effectiveness of triphenylbismuth and a few other bismuth compounds for use as a radiopacifying (X-ray contrast) additive in polymeric materials was tested. Ph3Bi was found to be compatible (sometimes up to 70 wt %) with a wide range of monomers and polymers. It yields homogeneous mixtures with polystyrene, poly(vinyl chloride), polyacrylates, polyethylene, and other polymers. They can be formed by solvent casting, by melt processing, or by polymerizing a Ph3Bi/monomer mixture. Polymerization is not affected by the presence of Ph3Bi even when amine accelerators are used. Radiopacities of the polymer mixtures are proportional to the molar content of Ph3Bi, and can easily exceed that of aluminum. The bismuth compound lowers the Tg of PVC, PMMA, and polystyrene by 1.3°C/wt % Ph3Bi. The additive is moisture-insensitive, water-insoluble, and heat-stable. It does not leach into water and has a low toxicity index. Leaching even in organic solvents can be prevented entirely by covalently binding bismuth to the polymer matrix through the use of monomers such as styryldiphenyl bismuth.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 55 (1995), S. 851-856 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Transparent, X-ray contrast (radiopaque) epoxy resins were obtained by dissolving up to 25 wt % triphenylbismuth in the commercial epoxy resin prepolymers EPON-815, DER-330, DER-383, and DEN-431 which were then hardened with diethylenetriamine. The radiopacities of the mixtures were found to be proportional to the molar concentration of the radiopaque additive. The systems follow the relationship, R = Ro + (Ra - Ro) Va Ma where R, Ro, and Ra are the radiopacities of the mixture, the pure epoxy resin, and triphenylbismuth, respectively (expressed in mm aluminum/mm resin); Ma and Va denote the molar concentration and molar volume of the bismuth compound. Ra for triphenylbismuth was found to be 7.4 ± 0.2 mm Al/mm resin; the average value of Ro for the four epoxies equals 0.16 ± 0.1 mm Al/mm resin. The amount of amine required to harden the radiopaque resins was far less for the epoxy novolac resin DEN-431 than for the three bisphenol-A based epoxies. The concentration of triphenylbismuth required to impart a radiopacity equivalent to that of aluminum measures 14.6 wt % in EPON-815, 14.8 wt % in DER-330, 14.9 wt % in DER-383, and 15.9 wt % in DEN-431. The radiopaque resins remain transparent indefinitely, even when exposed to water. © 1995 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 31 (1996), S. 339-343 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Previously we demonstrated the feasibility of using up to 24% triphenylbismuth (TPB) as a radiopaque, monomer-miscible additive for dental acrylic resins. In this study we examined the influence of TPB on thermomechanical properties of a representative polymethylmethacrylate (PMMA) ambient-cured resin used for temporary dental crowns and bridges. TPB (0%, 5%, 15% or 30% w/w) was dissolved in the monomer component, added to the powder component, and allowed to cure in rectangular molds. After 1 h they were either stored at 23°C for 23 h, or heated for 5 min at either 40°C or 50°C, and then stored for 23 h. They were then scanned from -10° to 125°C in a dynamic mechanical thermal analyzer using the three-point bending mode of deformation at 1-Hz frequency.The onset to the glass-transition temperature (Tg) is decreased by 13° to 32°C by addition of TPB, while the storage modulus (E′) at 25°C is either unchanged or is slightly increased. TPB did not interfere with the curing reaction, and postcure heating at 40°C had no effect on either E′ or Tg. However, heating at 50°C generally increased Tg but had very little effect on E′ throughout the 0-50°C operating temperature range. TPB crystals were observed to have precipitated at TPB levels above 8%. These crystals, dispersed throughout the PMMA, act as reinforcing fillers. This reinforcement can account for the lack of a decrease in E′, as would be expected if TPB had a plasticizing effect below Tg. However, even at 5%, a concentration at which all the TPB remains dissolved in the solid polymer, no decrease in E′ was observed. This implies that TPB exerts an antiplasticizing effect at temperatures below 50°C, possibly by occupying free volume among the polymer chains.It is concluded that TPB, in amounts adequate to impart diagnostic levels of radiopacity, is unlikely to adversely affect the clinical utility of PMMA-based dental acrylic resins. © 1996 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 1629-1638 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Insoluble complexes are formed in acidic aqueous media when poly(acrylic acid) (PAA) and poly-(vinylbenzo-18-crown-6) (P18C6) or polyvinylbenzoglymes are mixed. Complex formation results from hydrogen bonding between carboxyl groups and crown ether- or glyme-oxygen atoms as well as from hydrophobic interactions. The precipitation is pH dependent and was determined as a function of the ratio PAA to P18C6 or to polyglyme at different HCl concentrations in 10-4M solutions of polycrown or polyglyme. Precipitation is nearly quantitative in 0.01N HCl. The compositions of PAA/P18C6 precipitates were determined as a function of the initial PAA/P18C6 ratio in solution. The complexes with P18C6 can be solubilized in acidic media when crown-complexable cations (K+, Cs+, Ba2+) are added, but the charged P18C6 reprecipitates in basic solution as a polysalt complex with the PAA-polyanion. More stable PAA-P18C6 complexes in the form of fibers can be obtained by interfacial complex formation. Poly(methacrylic acid) is less effective as a complex former.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 18 (1980), S. 659-664 
    ISSN: 0360-6384
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 22 (1984), S. 617-621 
    ISSN: 0360-6384
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 2 (1981), S. 299-303 
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 2 (1981), S. 235-240 
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 8 (1987), S. 543-547 
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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