Premium
Concentrated solution and melt rheology of poly(vinylidene fluoride)
Author(s) -
Auyeung Kim Fung
Publication year - 1990
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.760300703
Subject(s) - viscometer , rheology , materials science , shear thinning , shear rate , rheometer , viscosity , composite material , molar mass distribution , polynomial , polymer chemistry , thermodynamics , polymer , mathematics , mathematical analysis , physics
The concentrated solution and melt rheology of poly(vinylidene fluoride) [PVDF] were studied by using a falling needle solution viscometer, a Brookfield viscometer, and a Kayeness capillary rheometer. It was found that the concentrated solution (15 wt% in N‐dimethyl acetamide) rheology exhibited a different behavior for various grades of PVDF produced by different types of polymerization. While Newtonian behavior was found in one type of PVDF, shear thinning was found in another type. The power law model was used to describe the general solution behavior of these materials. Zero shear rate viscosity correlated well with the molecular weight ( M w ) of the material. Melt viscosity of PVDF exhibited continuous shear thinning behavior throughout the whole range of shear rates. The data were best fitted by a second‐degree polynomial curve. Correlations were established between the molecular weight, molecular weight distribution, and the parameters of the polynomial curve. These correlations are useful for the prediction of various grades of PVDF designated for specific engineering applications. The correlations obtained from solution provided better and more accurate correlations to M w parameters than those of melt rheology.