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Rheological behavior of molten epoxide prepolymers
Author(s) -
Aleman J. V.
Publication year - 1978
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760181507
Subject(s) - prepolymer , materials science , rheology , shear rate , epoxide , shear (geology) , composite material , shear thinning , polymer chemistry , shear flow , thermodynamics , chemistry , organic chemistry , polyurethane , catalysis , physics
Flow properties of four molten epoxide prepolymers of number average molecular weight 900(I), 1,500(II), 2,100(III) and 4,000(IV), were measured at temperatures ranging from 361 to 463K, and shear rates from 500 to 10,000 s −1 . Apparent shear viscosities showed that all prepolymers used have Newtonian behavior up to shear rates of 2,000 s −1 . Shear thinning occurs at higher shear rates. Flow activation energies at constant shear rates in the range of 500 to 7,000 s −1 vary for prepolymer III from 5 to 24 kcal/mol, and for prepolymer IV from 9 to 25 kcal/mol. Flow indices in the same shear rate range vary for prepolymer III from 1.0 to 0.7 and for prepolymer IV from 1.0 to 0.3.