Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Chelating ability of poly(vinylamine): effects of polyamine structure on chelation (1989)
    s.l. : American Chemical Society
    Macromolecules 22 (1989), S. 2363-2366 
    Details
    ISSN: 1520-5835
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ma00195a062
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Highly monodisperse crosslinked polystyrene microparticles by dispersion polymerization (1998)
    Springer
    Colloid & polymer science 276 (1998), S. 870-878 
    Details
    ISSN: 1435-1536
    Schlagwort(e): Key words Highly monodisperse polystyrene microparticles ; the monomer-swellable surface ; long tetramethylene oxide groups ; the solubility of the monomer mixtures ; cloud points and fractional conversions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Abstract  Highly monodisperse polystyrene microparticles cross-linked with urethane acrylates were produced by dispersion polymerization in ethanol solution in the presence of 2,2′-azobis (isobutyronitrile) initiator, polyvinylpyrrolidone stabilizer, and Aerosol–OT costabilizer. Different from conventional crosslinkers, the urethane acrylates employed as a crosslinker showed an excellent effect on maintaining the monodispersity of polystyrene microparticles even in the moderate crosslinker concentration. This was believed that the urethane acrylate helped forming the monomer-swellable surface of primary particles, because of its structurally long tetramethylene oxide groups in its molecule. However, at high concentration of the urethane acrylate, the rough surface and the coagulum of particles were observed, which was attributed to the seriously decreased solubility of the monomer mixtures in ethanol solution. The solubility of the mixtures of styrene monomer and urethane acrylate in the media had a serious effect on the average particle size and morphology of the final particles. This could be confirmed by the measurement of cloud points and fractional conversions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003960050323
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Preparation of UV curable emulsions using PEG-modified urethane acrylates and their coating properties III: Effects of epoxy acrylate (1997)
    Springer
    Polymer bulletin 38 (1997), S. 287-294 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Abstract. Water-dispersible UV-curable urethane acrylate emulsions were prepared with polyethylene glycol (PEG)-modified urethane acrylates (PMUA), containing terminal hydrophilic polyoxyethylene chains. To improve physical properties of PMUA, epoxy acrylate (EA) having high thermal stability and hardness, was mixed with five kinds of PMUA containing different chain lengths of polyoxyethylene (POE). For PMUA/EA mixtures, the composition ratio of EA to PMUA and the chain length of POE greatly influenced the size of droplets of emulsions and the physical properties of their cured films. At higher EA to PMUA ratio, the physical properties decreased, which was due to phase separation between EA and PMUA. Phase separation was confirmed by scanning electron microscopy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002890050050
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Preparation of epoxy acrylate emulsion using mixed surfactants and its polymerization (1996)
    Springer
    Polymer bulletin 36 (1996), S. 141-148 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary A series of epoxy acrylate emulsions were prepared with several surfactants ranging from HLB 12 to 14 at 40°C. For epoxy acrylate emulsion, additives and conditions were established among factors: HLB value of emulsion, agitation speed, water dropping speed, and dropping amount of the deionized water. For emulsion polymereization with water soluble initiator KPS, emulsion was broken during polymerization, because interfacial complex formed by association of surfactant with co-surfactants stabilizing emulsion was weakened by interpenetration of radicals formed at aqueous. Accordingly, the polymerization of epoxy acrylate emulsion was carried out by using oil soluble initiator, AIBN, and the conversion changes with initiator concentration and HLB values were investigated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00294899
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Swelling behavior of novel polyurethane hydro-xerogels (1996)
    Springer
    Polymer bulletin 36 (1996), S. 737-744 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Polyurethane hydro-xerogels derived from PEG-modified urethane acrylates (PMUA), containing hydrophilic segment (polyoxyethylene groups) and hydrophobic segment at the same molecule, were prepared and their swelling behaviors were evaluated. Hydro-xerogels of PMUA were prepared using gelation process of PMUA emulsions. these gels could be swelled at both of water and dioxane, moreover, the swelling ratio of these gels at dioxane and water were changed with composition ratio of water to PMUA in the preparation of gel. In aqueous medium, swelling ratio of these gels increased with the increase in composition ratio of water to PMUA. However, in organic medium (Dioxane), swelling ratio decreased as the composition ratio of water increased. Additionally, as the reaction molar ratio of PEG to 2-HEMA increased, swelling ratio of gels at water increased. These results were due to microstructure of PMUA gels, which was formed by phase separation between hydrophilic and hydrophobic segments in the course of gelation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00338638
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Synthesis of new pH-sensitive polyurethane gels using polyethylene glycol modified urethane acrylate and urethane acrylate anionomer (1997)
    Springer
    Polymer bulletin 38 (1997), S. 403-410 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Abstract. New type of amphiphilic pH-sensitive polyurethane networks, derived from the mixture of polyethylene glycol-modified urethane acrylates (PMUA) and urethane acrylate anionomer (UAA), were prepared and their swelling behaviors were evaluated. Three kinds of polymerization methods were employed in the synthesis of polyurethane networks. Polyurethane networks prepared by a process similar to that of soap-free emulsion polymerization (UAHG) showed the highest swelling ratio and pH-sensitivity. Additionally, four kinds of UAHG gels were prepared at different composition of UAA. As the composition ratio of UAA to PMUA increased, swelling of UAHG gels in alkali pH buffer solution and their pH-sensitivity greatly increased. Additionally, swelling of UAHG gels changed reversibly with the change of pH.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002890050066
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Monodisperse micron-sized polymethylmethacrylate particles having a crosslinked network structure. V (2000)
    Springer
    Journal of materials science 35 (2000), S. 6181-6188 
    Details
    ISSN: 1573-4803
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract Highly monodisperse micron-sized polymethylmethacrylate (PMMA) particles crosslinked with carboxylic group-containing urethane acrylates (CUA) were produced by simple dispersion polymerization in methanol. In proper condition, CUA employed as a crosslinker had an excellent ability to achieve the monodisperse PMMA particles to the concentration of about 10 wt%. This arose from the fact that CUA formed monomer-swellable primary particles due to its structurally long tetramethylene oxide groups in the molecule. The influence of the concentrations of the initiator and CUA on the particle diameter (D n), particle number density (N p), and polymerization rate (R p) was found to obey the following approximate relationship, D n ∝ [initiator]0.41[CUA]−0.06, N p ∝ [initiator]−1.22 [CUA]0.21, and R p ∝ [initiator]0.34±0.03, respectively. The power law dependence of D n and N p on the initiator concentration coincided well with that of linear polymers in the literature. Especially, in this study, it was found that CUA did not have a serious influence on the nucleation. However, the dependence of R p on the initiator concentration was observed to be higher than that of linear polymers, suggesting that uniquely, the solution polymerization process competed with the heterogeneous polymerization during polymerization, because of the crosslinked network structure of the primary particles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1026773009436
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Synthesis of water-soluble urethane acrylate anionomers and their ultra-violet coating properties (1999)
    Springer
    Journal of materials science 34 (1999), S. 5343-5349 
    Details
    ISSN: 1573-4803
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract Water-soluble and ultraviolet (UV)-curable urethane acrylate anionomers containing dimethylolpropionic acid (DMPA) were synthesized with varying molecular weight of soft segment and degree of neutralization. The ion group incorporated was confirmed by 1H-NMR and 13C-NMR spectra. In viscosity measurements, the enhancement of viscosity was achieved with increasing of ionic strength or pH of the solution. However, when the molecular weight of soft segment was high, the viscosity little changed for given parameters. This indicates that the strong hydrophobic interaction caused by the long soft segment made the anionomer chain aggregate. The UV coating properties of urethane acrylate anionomer films were depended on the molecular weight of soft segment and the degree of neutralization. For the films of high ion content and low molecular weight of soft segment, the tensile strength had a tendency toward increasing, on the contrary, for the films of low ion content and high molecular weight of soft segment, the tensile strength displayed reverse tendency. However, compared with general urethane acrylate films, overall coating properties were significantly improved. This was believed that the ionic groups acted as reinforcing filler by means of the phase separation from the crosslinked urethane acrylate network.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004757223320
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Compatibilizing effect of isocyanate functional group on polyethylene terephthalate/low density polyethylene blends (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 447-453 
    Details
    ISSN: 0887-6266
    Schlagwort(e): polyethylene terephthalate ; low density polyethylene ; isocyanate functional group ; compatibility ; crystallization ; Physics ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: To evaluate the compatibilizing effects of isocyanate (NCO) functional group on the polyethylene terephthalate/low density polyethylene (PET/LDPE) blends, LDPE grafted with 2-hydroxyethyl methacrylate-isophorone diisocyanate (LDPE-g-HI) was prepared and blended with PET. The chemical reaction occurred during the melt blending in the PET/LDPE-g-HI blends was confirmed by the result of IR spectra. In the light of the blend morphology, the dispersions of the PET/LDPE-g-HI blends were very fine over the PET/LDPE blends. DSC thermograms indicated that PET microdispersions produced by the slow cooling of the PET/LDPE-g-HI blends were largely amorphous, with low crystallinity, due to the chemical bonding. The tensile strengths of the PET/LDPE-g-HI blends were higher than those of the PET/LDPE blends having a poor adhesion. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 447-453, 1998
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
  • 10
    Digitale Medien
    Digitale Medien
    Influence of physical relaxation on chemical stress-relaxation of natural rubber vulcanizates (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 223-233 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Networks were prepared in the swollen and dry states to investigate the influence of physical relaxation on chemical stress-relaxation. The stress-relaxation behavior of solution-cured samples was different significantly from that of the samples crosslinked conventionally. The same result was also observed in the number of chain scission for both kinds of samples. On the other hand, the number of chain scission estimated by using the swelling method for samples crosslinked conventionally was in good agreement with that by the chemical stress-relaxation for solution-cured samples. It was found that there is little or no influence of the physical relaxation caused by entanglements, and no effect of dangling chains arising from scission in the equilibrium swelling. The relative change of network chain density determined by means of the swelling method was also consistent with that by sol fraction determination. These results indicate that the swelling method can be used as a measure of a degree of degradation on chemorheology. Taking into account the influence of physical relaxation on chemical stress-relaxation, a new relationship between the relative stress decay and the relative network chain density was experimentally proposed.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1987.070340119
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...