Title: Temperature and torsion strain analysis of the dynamical visco-elastic properties of high-density polyethylene

Authors: M. Mateev, S. Karageorgiev

Addresses: Experimental Physics Department, University of Plovdiv, Tsar Assen str. 24,4000 Plovdiv, Bulgaria ' Lab Electron Microscopy, High Institute of Agriculture, Mendeleev str. 12, 4000 Plovdiv, Bulgaria

Abstract: The behaviour of the dynamical visco-elastic functions in high-density polyethylene (HDPE), which carries the trade mark |Bulen|, in the region of gamma and beta relaxation transitions has been studied. The method of forced torsion vibrations was used to obtain the curves for the storage modulus (G|), loss modulus (G′), loss modulus (C″) and loss tangent (tgδ) in the temperature interval (-180 to + 20)°C and torsion strain (0.01 to 1.2)%. The loss functions show extremes at torsion strain S = 0.1% for the gamma relaxation transition and at S = 1.0% for the beta relaxation transition, which are explained with reference to the processes of the deformational orientation of the macromolecular chain segments, change in the micro-Brownian macromolecular mobility, the degree of anelastic intermolecular interactions, etc. The scanning electron microscopy (SEM) study shows a strong integration of the segments of the macromolecular chains into sublevels of the superstructural molecular organization and at the same time local co-operation of the sublevels.

Keywords: dynamo-mechanical analysis; modulus of elasticity; morphology; polyethylene; relaxation transitions; scanning electron microscopy; SEM; temperature; torsion strain analysis; viscoelasticity; HDPE.

DOI: 10.1504/IJMPT.1994.036424

International Journal of Materials and Product Technology, 1994 Vol.9 No.4/5/6, pp.300 - 309

Published online: 03 Nov 2010 *

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