Creep recovery of random ethylene-octene copolymer melts with varying comonomer content

Bhaskar Patham, Krishnamurthy Jayaraman

    Research output: Research - peer-reviewArticle

    • 18 Citations

    Abstract

    This paper presents an investigation of the effects of varying comonomer content from 20 to 38 wt % in random ethylene-octene copolymers made with a metallocene catalyst on the melt rheology including transients in shear creep recovery from high strains. The copolymer with 20% octene appeared to be the same as that reported to be long-chain branched in the literature and was used as a reference material. The materials were characterized in oscillatory shear and shear creep at stresses ranging from 5 to 30 000 Pa. Van Gurp-Palmen plots prepared from dynamic modulus data and zero-shear viscosity values from creep tests at very low stress confirmed that the reference material was long-chain branched and established that long-chain branching was absent from the copolymer with the highest comonomer content. The steady state recoverable shear compliance values for the three copolymers were very close. However, following large shear deformations brought about at higher strain rates, strain recovery was reduced most significantly for the copolymer with the highest comonomer content where long-chain branching was absent. The reduction in recovery at short times was also most significant for this copolymer.

    LanguageEnglish (US)
    Pages989-999
    Number of pages11
    JournalJournal of Rheology
    Volume49
    Issue number5
    DOIs
    StatePublished - 2005

    Profile

    copolymers
    ethylene
    recovery
    Creep
    Copolymers
    Recovery
    Ethylene
    shear
    shear creep
    creep tests
    trucks
    rheology
    strain rate
    plots
    viscosity
    catalysts
    Shear viscosity
    Rheology
    Shear deformation
    Strain rate

    ASJC Scopus subject areas

    • Mechanics of Materials
    • Computational Mechanics
    • Physics and Astronomy(all)

    Cite this

    Creep recovery of random ethylene-octene copolymer melts with varying comonomer content. / Patham, Bhaskar; Jayaraman, Krishnamurthy.

    In: Journal of Rheology, Vol. 49, No. 5, 2005, p. 989-999.

    Research output: Research - peer-reviewArticle

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