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Role of capillary end correction in flow analysis of molten polyethylene
Author(s) -
Ram A.,
Narkis M.
Publication year - 1966
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1966.070100302
Subject(s) - capillary action , branching (polymer chemistry) , polyethylene , materials science , shear stress , mechanics , shear (geology) , shear modulus , thermodynamics , shear flow , composite material , physics
Abstract The role of the capillary end correction in flow analysis of molten low‐density polyethylenes has been analyzed. In spite of limitations of accuracy a quantitative approach has been undertaken. The results are much more complicated than predicted by Bagley in his early reports. The elastic component of the end correction is controlled by shear stress and shear modulus. The latter is affected by the size of the subchain between entangles, M e , and by the degree of long‐chain branches. Both are eventually dependent on the length of the chain, i.e., its molecular weight. In addition shear stress and temperature affect the process of disentanglement. Capillary end correction increases with increasing molecular weight and shear stress and with decreasing temperature. The available analysis of branching is still in controversy, and therefore no numerical parameters are yet proposed. A consistent theory of the response of entanglement couplings to shear forces and temperature is evaluated.