Molecular Structure of High Pressure Polyethylene

Bibliographic Information

Other Title
  • 高圧法ポリエチレンの分子構造の研究
  • VI. Expansion Factors of Some Commercial High Pressure Polyethylenes and Consideration on MI- [η] Correlation
  • 第6報 市販高圧法ポリエチレンのexpansion factorとMI- [η] の関係

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Description

On some typical commercial high pressure polyethylenes, [η] (145°C, dioctyl adipate) was measured, and assuming them as [η] θ, the expansion factors (α3η≡ [η] (75°C, xylene) / [η] θ) were determined.<BR>Vessel-type polyethylenes generally showed a tendency to have larger α3η than that of tubular-type polyethylenes and this tendency was more remarkable for the samples fractionated by molecular weight.<BR>The expansion factor of linear polyethylene was smaller than that of high pressure polyethylenes and it hardly varied with molecular weight. As the addition of long-chain branchings by gamma ray irradiation did not vary the value of α3η of linear polyethylene, it was considered that large α3η for high pressure polyethylenes is not due to the presence of long-chain branching itself but due to the presence of “complicated long-chain branchings having many short-chain branchings” . Expansion factors of the high pressure polyethylenes increased with molecular weight and this result was considered to be caused by the fact that the amount of complicated long-chain branchings increases with increasing molecular weight. MI- [η] correlation could be explained by two effects which are the effect of degree of long-chain branching itself on the melt viscosity-solution viscosity correlation and the change of excluded volume effect due to the presence of complicated long-chain branchings.

Journal

  • Kobunshi Kagaku

    Kobunshi Kagaku 28 (312), 312-320, 1971

    The Society of Polymer Science, Japan

Details 詳細情報について

  • CRID
    1390282681497563904
  • NII Article ID
    130003835987
  • DOI
    10.1295/koron1944.28.312
  • ISSN
    18848079
    00232556
  • Text Lang
    ja
  • Data Source
    • JaLC
    • Crossref
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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