ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1990-1994
  • 1985-1989  (2)
  • 1989  (2)
Collection
Publisher
Years
  • 1990-1994
  • 1985-1989  (2)
Year
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 789-801 
    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: An ethylene-propylene copolymer (EPR) has been functionalized with dibutyl maleate (DBM) by means of a radical-initiated bulk process. Different degrees of grafting have been obtained by varying the overall composition of the reaction mixture as well as the processing procedures. The influence of the grafting degree on the structural and superreticular (or “long range”) order has been investigated by differential scanning calorimetry (DSC), Fourier transform infrared analysis (FTIR), and wide (WAXS) and small angle X-ray scattering (SAXS) techniques. The functionalization leads to a decrease of the “residual crystallinity” present in the parent copolymer. Linear relationships between the grafting degree and the crystallinity degree Xc evaluated by both DSC and WAXS have been obtained. The results of the structural investigations, in agreement with previously reported ones, suggest that the grafting preferentially occurs onto the longer or more perfect methylene sequences. SAXS investigations showed that the significant degree of structuration, i.e., crystalline and paracrystalline order, present in the parent elastomer, gradually disappears by increasing the degree of grafting.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    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 effect of the dicumylperoxide (DCPO) concentration on the kinetics of the bulk functionalization of an ethylene-propylene copolymer (EPR) has been studied. It has been found that, enhancing the DCPO initial concentration in the reaction mixture, results in both increased initial reaction rate and grafting process efficiency. DCPO content also affects degradation, which always accompanies the grafting reaction. At high DCPO content, products with a high degree of grafting and intrinsic viscosity close to that of the parent copolymer can be obtained. Furthermore, the influence of the EPR composition and chain microstructure on the functionalization as well as on the degradation processes has been investigated. By increasing the C2 content in EPRs prepared by using vanadium-based conventional catalysts, obtains faster functionalization kinetics and a less pronounced degradation of the products. At fixed experimental conditions, the highest grafting degrees have been obtained by using EPRs prepared by high-yield titanium catalysts and characterized as a block-like microstructure. The experimental results have been interpreted on the basis of a proposed reaction mechanism.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...