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Rheology of silicon carbide/vinyl ester nanocomposites
Author(s) -
Yong Virginia,
Hahn H. Thomas
Publication year - 2006
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.24962
Subject(s) - dispersant , materials science , volume fraction , viscosity , nanocomposite , rheology , silicon carbide , composite material , vinyl alcohol , nanoparticle , mass fraction , particle (ecology) , particle size , chemical engineering , polymer chemistry , dispersion (optics) , polymer , nanotechnology , physics , oceanography , engineering , geology , optics
Silicon carbide (SiC) nanoparticles with no surface treatment raise the viscosity of a vinyl ester resin much more intensely than micrometer‐size SiC particles. An effective dispersant generally causes a reduction in the resin viscosity attributed to its surface‐active properties and thereby increases the maximum fraction of particles that can be introduced. This article assesses the rheological behavior of SiC‐nanoparticle‐filled vinyl ester resin systems with the Bingham, power‐law, Herschel–Bulkley, and Casson models. The maximum particle loading corresponding to infinite viscosity has been determined to be a 0.1 volume fraction with the (1 − η r −1/2 )–ϕ dependence (where η r is the relative viscosity and ϕ is the particle volume fraction). The optimum fractional weight percentage of the dispersants (wt % dispersant/wt % SiC) is around 40% for 30‐nm SiC nanoparticles, which is much higher than 1–3% for micrometer‐size particles. SiC nanoparticles at a concentration of 9.2 wt % (0.03 volume fraction) cause a fourfold increase in the resin viscosity. The addition of a dispersant at the optimum dosage lowers the viscosity of SiC/vinyl ester suspensions by 50%. The reduction in the viscosity is substantial to improve the processability of SiC/vinyl ester nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4365–4371, 2006