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Thixotropic properties

The property of thixotropy ia various degrees of complexity (3). Thixotropic properties may lead to loss of stabiUty as shown by the sometimes catastrophic flow of quick clays, especially ia Norway, Sweden, and Canada (15). [Pg.194]

An advanced solution to the problem of decreasing the free mobility of the electrolyte in sealed batteries is its gel formation. By adding some 5-8 wt.% of pyrogenic silica to the electrolyte, a gel structure is formed due to the immense surface area (-200-300 m2 g ) of such silicas, which fixes the sulfuric acid solution molecules by van der Waals bonds within a lattice. These gels have thixotropic properties i.e., by mechanical stirring they can be liquefied and used to Filled into the... [Pg.280]

Of course, measurements of amplitude dependence of the elastic modulus of a filled composition may, by itself, give an interesting material on thixotropic properties of such materials. Indeed, very strong effects are observed here. Thus, in a melt containing... [Pg.93]

The area of the hysteresis loop is a measure of the thixotropy of the tested system. These measurements are easy to carry out and give a quick overview of the thixotropic properties of... [Pg.412]

Clay materials show a different behavior. They are either cation-poor or cation-rich sheet silicates. They can swell by taking up varying amounts of water between the sheets. If the intercalated cations are hydrated as in montmorillonite, they act as cation exchangers. Montmorillonite, especially when it has intercalated Ca2+ ions, has thixotropic properties and is used to seal up drill holes. The effect is due to the charge distribution on... [Pg.183]

An overview of the origins of yield stress and parameters which can lead to variations in behaviour with highly filled polymer dispersions is given by Malkin [1]. Much of the following literature, describing experimental work undertaken, demonstrates that yield phenomena can be correlated with the extent of interaction between the filler particles and the formation of a network structure. However, the actual behaviour observed during experimentation may also depend on the deformation history of the material, or the time and temperature of imposed deformation, especially if the material exhibits thixotropic properties. [Pg.170]

Various salts other than the sodium salt have also received attention in this field. For example, lacquer films are prepared by the co-precipita-tion of a resin acid with aluminum carboxymethylcellulose,84 and the barium salt86 is said to possess thixotropic properties useful in paints. One unusual application involves the preparation of the water-soluble ferrous salt86 of carboxymethylcellulose which, when applied (for example to wall-... [Pg.295]

All of the products, with the possible exception of particleboard wood sander dust, yield varying degrees of thixotropic properties which permit easy application, yet fixed in a consistent pattern after application. [Pg.284]

Due to the variety in porous structure, particle size and surface area, pure silica gels and powders find a very wide range of applications. Variation in preparation methods and parameters allows the tailoring of the substrate properties for specific application needs. The main features in the silica applications are its porosity, active surface, hardness, particle size and the viscous and thixotropic properties. Although most applications are based on a combination of those, a classification according to the main properties of interest may be set up. For references, the reader is referred to the works of Iler6 and Unger7 and to the references cited in chapter 8. [Pg.27]

Mixtures of the monotriethanolamine titanate and polyols, such as fructose and sorbitol, imparted thixotropic properties to polymer-containing cement (107). A similar reaction of triethanolamine and tetraalkyl titanates previously treated with stearic acid gives the corresponding 1-acyloxytitatranes (108). Aqueous dispersions of these materials can be used to treat fabrics to impart a high degree of water repellency. [Pg.148]

The addition of asbestos fibers at one time provided excellent thixotropic adhesive formulations, especially at elevated temperatures. However, health and environmental regulations have severely limited the use of this material. Today, fumed silica, precipitated calcium carbonate, certain clays, and cellulose and other fibers offer thixotropic properties at relatively low levels of loading. [Pg.164]

Fumed silica is typically available with sizes of 7 to 40 nm and surface areas ranging from 50 to 380 m2/g. Unlike precipitated silica, fumed silica has no internal surface area. The specific gravity of fumed silica is approximately 2.2. Because of its high surface area to weight ratio, formulations generally require only a minor amount of fumed silica (1 to 5 percent by weight) to achieve thixotropic properties. [Pg.166]

Calcium carbonate filler is a particulate filler that is generally employed to impart thixotropic properties and as an extender. However, improvements in physical properties such as tensile strength, tear, and elongation have been noticed as a function of surface area. This effect is noted more so with the coated CaC03 products. [Pg.176]

Physical hydrogels were formed induced by self-assembled water-insoluble and crystalline polypseudorotaxane domains which act as physical crosslinking points. Such physical hydrogels include the polypseudorotaxane systems of a-CD threading on PEO or its copolymers, a-CD threaded on PEI, PL, or their copolymers, and even 3-CD or y-CD threaded PPO or PEI copolymers. The thermo-reversible and thixotropic properties of these supramolecular hydrogels have inspired their applications as injectable drug delivery systems. Physical hydrogels induced by physical interaction of threaded CD molecules in polyrotaxanes were also developed. [Pg.110]

Properties (Wyoming) Light to cream-colored impalpable powder forms colloidal suspension in water, with strongly thixotropic properties. [Pg.132]

Properties Colorless, odorless, nontoxic, water-soluble powder or granules. D 1.59, refr index 1.51, tensile strength 8000-15,000 psi, pH (1% solution) 6.5-8.0, stable in pH range 2-10. Viscosity of 1% solution varies from 5 to 2000 cP, depending on the extent of etherification. Insoluble in organic liquids. Reacts with heavy-metal salts to form films that are insoluble in water, transparent, relatively tough, and unaffected by organic materials. Many of its colloidal properties are superior to those of natural hydrophilic colloids. It also has thixotropic properties and functions as a polyelectrolyte. [Pg.238]

Fillers are used in these products to improve mechanical properties or impart flammability resistance. Fillers are frequently silane-treated to further improve mechanical properties. Fillers must have a low moisture (below 0.1%), a low absorption of resin, and are expected to impart thixotropic properties. There are special cases. For example, if peroxyketals are used as initiators, basic fillers have to be used because acidic fillers interfere with cure times and the shelf-life of the composition. Shape and particle size distribution must be considered in filler selection to impart the desired rheological properties. Calcium carbonate is the most popular filler but aluminum trihydrate, anhydrous calcium sulfate, and silica are also frequently used. Barite is well suited to this application, especially if acid... [Pg.772]


See other pages where Thixotropic properties is mentioned: [Pg.175]    [Pg.143]    [Pg.148]    [Pg.186]    [Pg.356]    [Pg.72]    [Pg.138]    [Pg.142]    [Pg.150]    [Pg.87]    [Pg.111]    [Pg.588]    [Pg.44]    [Pg.20]    [Pg.36]    [Pg.207]    [Pg.489]    [Pg.262]    [Pg.356]    [Pg.405]    [Pg.439]    [Pg.5185]    [Pg.236]    [Pg.682]    [Pg.588]    [Pg.604]    [Pg.644]    [Pg.79]    [Pg.97]    [Pg.75]    [Pg.140]    [Pg.251]    [Pg.170]   
See also in sourсe #XX -- [ Pg.243 ]

See also in sourсe #XX -- [ Pg.2 , Pg.75 , Pg.412 ]

See also in sourсe #XX -- [ Pg.134 , Pg.242 ]




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