Journal
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
Volume 320, Issue -, Pages 235-248Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0378-4371(02)01524-8
Keywords
polymer melt; glass transition; shear rheology; viscoelastic behavior; heterogeneity
Categories
Ask authors/readers for more resources
This article describes shear-experiments on flexible linear polymer melts (polystyrene) with molecular weights (4,000 and 17, 500 g/mol) lower than that of critical entanglement. The technique used is a shear piezoelectric rheometer, enabling the complex slicar-modulus to be measured in a broad frequency domain (ranging from a few hundredths Hz to some kHz), for weak imposed strains (similar to10(-4)), and for thicknesses between 15 and 100 mum. The results obtained show that the behavior of the shear modulus progressively shifts from a liquid-type behavior to a solid-type as sample-thickness decreases from 100 to 15 mum. This unexpected change in behavior, which is only observed for strong anchoring conditions of the polymer on the substrate, indicates the presence of macroscopic heterogeneities (elastic clusters). We show that these clusters are associated with the glass transition and suggest that they are due to long-range density-fluctuations which are frozen as a result of their ultra-slow relaxation times and thus display an elastic response. (C) 2002 Elsevier Science B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available