Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    Electronic Resource
    Electronic Resource
    Mechanism of radiation vulcanization of natural rubber latex sensitized by monoacrylates (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 57 (1995), S. 1155-1171 
    Details
    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 mechanism of radiation vulcanization of natural rubber with 2-ethyl hexyl acrylate (2EHA) monomer was investigated using electron spin resonance spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The primary radicals formed in the arcylate molecule were found to abstract the allylic hydrogens of the polyisoprene. Crossliking may occur through the allylic radicals and/or main chain radicals formed on the polyacrylate. Acrylate was found to concentrate in the rigid regions of the crosslinked rubber indicating heterogeneity and a nonuniform distribution of the acrylate in the latex particles. The addition of the acrylate and the irradiation seems to effect the Brownian motion of the latex particles. Both the viscosity and the NMR peak widths are effected by the irradiation. Addition of 5% 2EHA increases the crosslinking by a factor of 3.6. The thermal stability of the rubber first increases with the dose in the presence of acrylate, but drops at higher doses due to peroxide formation. © 1995 John Wiley & Sons, Inc.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1995.070571002
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Development of wear-resistant thermoplastic polyurethanes by blending with poly(dimethyl siloxane). I. Physical properties (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 1757-1766 
    Details
    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: Commercial thermoplastic polyurethanes have been melt blended on a standard laboratory extruder with low levels of commercial poly(dimethyl siloxane) fluid. The resultant polyurethanes show improvements in wear resistance of up to 25% (c.f. virgin polyurethane) for an optimal PDMS concentration of 1.5-2.0%, beyond which the properties diminish rapidly. Unexpectedly, the mechanical properties of the blends (as measured by an Instron tensile testing machine) have been even more significantly enhanced, by up to 40% for tensile strength and 50% for elongation to break. Surface studies of the blends are also reported for x-ray photoelectron spectroscopy (XPS), contact angles and coefficient of friction (CoF). © 1996 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 13
    Electronic Resource
    Electronic Resource
    Free volume and water uptake in a copolymer hydrogel series (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 463-471 
    Details
    ISSN: 0887-6266
    Keywords: hydrogel ; free volume ; positron annihilation ; water ; density ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A copolymer of 2-hydroxyethyl methacrylate (HEMA) with 2-ethoxy ethyl methacrylate (EEMA) was synthesized and the molecular mobility, free volume, and density properties examined as a function of composition. These properties were correlated with the equilibrium water uptake in order to determine which of the properties were most influential in causing high water sorption, as these materials are suitable candidates for hydrogel systems. It was found that the polar HEMA repeat unit results in a rigid, glassy sample at room temperature due to the high degree of hydrogen bonding between chains whereas high EEMA content leads to rubbery samples with subambient glass transition temperatures. The free volume properties on the molecular scale measured by positron annihilation lifetime spectroscopy (PALS) showed that higher HEMA content led to smaller, fewer holes and a lower free volume fraction than EEMA. Therefore the high water uptake of HEEMA-containing copolymers is largely related to the high polarity of the HEMA unit compared to EEMA, despite the low content of free volume into which the water can initially diffuse. Trends in density with copolymer composition, as measured on a macroscopic level, differs to that seen by PALS and indicates that the two techniques are measuring different scales of packing. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 463-471, 1998
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...