LABORATORY REPORT NO. IO OXIDES DIVISION
CABOT CORPORATION
DEPT. CN 10. 125 HIGH STREET, BOSTON, MASS. 02110
how dispersion methods affect thickening efficiency
.f CAB-O-SIL
100,001
For any given piece of dispersion equipment, there is a point at which continued agitation has no effect on the degree of dispersion. At this point the viscosity and thixotropy remain constant, and if CAB-O-SIL is well dis persed, maximum stability on aging is obtained.
10,000
Low shear equipment, such as simple propeller stirrers, is suitable for very polar, high hydrogen-bonding liquids. When used with medium-polar and non-polar liquids, however, the mixing time should be increased to obtain the best dispersion possible with this equipment.
1.000
100
High shear equipment produces a greater degree of dispersion in a shorter period of time for all liquids. Sonic or mechanical homogenizers, high-speed stirrers, colloid mills, kneaders, and roll mills are high shear. TYPICAL EXAMPLES Approximately 7% CAB-O-SIL M-5 was dispersed at low shear in ethanol, and a cationic surfactant added to achieve a certain viscosity. The same viscosity was ob tained with only 5% CAB-O-SIL dispersed with high shear equipment, with the same amount of cationic ad ditive — a reduction of greater than 28% in material costs. In a polyester resin 2% CAB-O-SIL M-5, dispersed at low shear, gave an apparent viscosity of 7500 cps; the addi tion of 0.4% ethylene glycol increased the viscosity to 9000 cps (a 20% increase). When 2% CAB-O-SIL M-5 was added at high shear, with the same amount of addi tive, viscosity increased 9 4 % to 12,000 cps, or 3 3 % more than with corresponding low shear equipment. In a mineral oil 2% CAB-O-SIL M-5 added at low shear showed viscosity of 2800 cps. The same amount dis persed at high shear increased viscosity to 32,000 cps.
Effect of mixing time (min.) in Waring Blendor on viscosity of mixtures of butanol, a polyester resin, and a mineral oil.
With 0.4% water, viscosity increased to nearly 100,000 cps. For more information on how to get the most for your money in thickening efficiency with CAB-O-SIL, write for our 8-page technical brochure, "How to Thicken Liquids with CAB-O-SIL" (CTh-2), or see our insert in the 1966 edition of Chemical Materials Catalog, Section C - l . CAB-O-SI Lis a fire-dry 99% pure fumed silica with a par ticle size of 0.015 micron, surface area of 200 m2/gm, bulk density of 2.3 lb./cu. ft.
2 % CAB-O-SIL M-5 IN POLYESTER RESIN
C A B O T C O R P O R A T I O N — OXIDES DIVISION Dept. CN10, 125 High Street, Boston, Mass. 02110
D RUSH FREE SAMPLE and literature on CAB-O-SIL Π Please call me for appointment. Tel.: I am especially interested in
Name_ Title
10
15
20 Waring Blendor
MINUTES Viscosity at point A is slightly higher than at point Β and beyond, where viscosity begins to level off. At point Β and beyond the maximum stability on aging is obtained.
I I
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