Fast determination of polymer melt viscosity by optical falling needle viscometer

Authors

  • Benjamin Chu,

    Corresponding author
    1. Chemistry Department, State University at Stony Brook, Stony Brook, New York 11794–3400
    2. Department of Materials Science and Engineering, State University at Stony Brook, Stony Brook, New York 11794–2275
    • Chemistry Department, State University at Stony Brook, Stony Brook, New York 11794–3400
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  • Jian Wang,

    1. Chemistry Department, State University at Stony Brook, Stony Brook, New York 11794–3400
    2. Department of Chemical and Nuclear Engineering, University of California, Santa Barbara, California 93106–5080
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  • William H. Tuminello

    1. E. I. Du Pont de Nemours and Company, Experimental Station, P. O. Box 80356, Wilmington, Delaware 19880–0356
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Abstract

An optical falling needle rheometer was employed to measure the melt viscosity of high density polyethylene (HDPE) and low molecular weight poly (tetrafluoroethylene) (PTFE). The temperature dependence of the melt viscosity of these two polymers was obtained and described by an empirical Arrhenius relation. At the present time, this method has been confirmed to be a simple and fast (within several tens of seconds for each measurement) approach to determine polymer melt viscosities of up to at least 1×105 Pa s. The sample cell containing ∼ 2.5 cm3 materials can be vacuum sealed and disposed of without the need of subsequent cleaning each time, which could be a useful feature. In comparison with HDPE, the PTEF sample melt was found to show a much higher melt viscosity with about the same degree of polymerization. © 1993 John Wiley & Sons, Inc.

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