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Poly thickeners

HydrophobicaHy Modified, Ethoxylated Urethane. HEUR associative thickeners are in effect poly(oxyethylene) polymers that contain terminal hydrophobe units (66). They can be synthesized via esterification with monoacids, tosylation reactions, or direct reaction with monoisocyanates. There are problems associated with aH of the methods of synthesis. The general commercial procedure for their synthesis is by a step-growth addition of... [Pg.321]

Suitable protective coUoids for the preparation of acryhc suspension polymers include ceUulose derivatives, polyacrylate salts, starch, poly(vinyl alcohol), gelatin, talc, clay, and clay derivatives (95). These materials are added to prevent the monomer droplets from coalescing during polymerisation (110). Thickeners such as glycerol, glycols, polyglycols, and inorganic salts ate also often added to improve the quahty of acryhc suspension polymers (95). [Pg.169]

Cellulosics. CeUulosic adhesives are obtained by modification of cellulose [9004-34-6] (qv) which comes from cotton linters and wood pulp. Cellulose can be nitrated to provide cellulose nitrate [9004-70-0] which is soluble in organic solvents. When cellulose nitrate is dissolved in amyl acetate [628-63-7] for example, a general purpose solvent-based adhesive which is both waterproof and flexible is formed. Cellulose esterification leads to materials such as cellulose acetate [9004-35-7], which has been used as a pressure-sensitive adhesive tape backing. Cellulose can also be ethoxylated, providing hydroxyethylceUulose which is useful as a thickening agent for poly(vinyl acetate) emulsion adhesives. Etherification leads to materials such as methylceUulose [9004-67-5] which are soluble in water and can be modified with glyceral [56-81-5] to produce adhesives used as wallpaper paste (see Cellulose esters Cellulose ethers). [Pg.234]

Other thickeners used include derivatives of ceUulose such as methylceUulose, hydroxypropylmethylceUulose, and ceUulose gum natural gums such as tragacanth and xanthan (see Cellulose ethers Gums) the carboxyvinyl polymers and the poly(vinyl alcohol)s. The magnesium aluminum siHcates, glycol stearates, and fatty alcohols in shampoos also can affect viscosity. [Pg.450]

The viscosity of the latex can also be dependent on pH. In the case of some latices, lowering the pH with a weak acid such as glycine is an effective method for raising the viscosity without destabilising the system. Latices made with poly(vinyl alcohol) as the primary emulsifier can be thickened by increasing the pH with a strong alkaU. [Pg.28]

Fig. 13. Thickening of lOW base stock to multigraded oil with polymer additives. A, high mol wt poly(alkyl methacrylate) B, low mol wt poly(aLkyl... Fig. 13. Thickening of lOW base stock to multigraded oil with polymer additives. A, high mol wt poly(alkyl methacrylate) B, low mol wt poly(aLkyl...
In fluorescent lamps, phosphors are coated on the inside of the lamp tube using a slurry containing the powder and a Hquid which is either poured down through the tube, up-flushed, or in some cases the tubes are filled and then drained. Because of concerns over having volatile organic solvents in the air, the hquid medium containing the powder is usually water with an added agent, a thickener, to increase the viscosity of the suspension, such as poly(methacryhc... [Pg.286]

Thickeners. Thickeners are added to remover formulas to increase the viscosity which allows the remover to cling to vertical surfaces. Natural and synthetic polymers are used as thickeners. They are generally dispersed and then caused to swell by the addition of a protic solvent or by adjusting the pH of the remover. When the polymer swells, it causes the viscosity of the mixture to increase. Viscosity is controlled by the amount of thickener added. Common thickeners used in organic removers include hydroxypropylmethylceUulose [9004-65-3], hydroxypropylceUulose [9004-64-2], hydroxyethyl cellulose, and poly(acryHc acid) [9003-01-4]. Thickeners used in aqueous removers include acryHc polymers and latex-type polymers. Some thickeners are not stable in very acidic or very basic environments, so careful selection is important. [Pg.550]

Functional derivatives of polyethylene, particularly poly(vinyl alcohol) and poly(acryLic acid) and derivatives, have received attention because of their water-solubility and disposal iato the aqueous environment. Poly(vinyl alcohol) is used ia a wide variety of appHcations, including textiles, paper, plastic films, etc, and poly(acryLic acid) is widely used ia detergents as a builder, a super-absorbent for diapers and feminine hygiene products, for water treatment, ia thickeners, as pigment dispersant, etc (see Vinyl polymers, vinyl alcohol polymers). [Pg.479]

Because the viscosity of neoprene latex at a given soHds content is less than that of natural mbber latex, thickeners are generally needed with the former. MethylceUulose and the water-soluble salts of poly(acryhc acid) are the two most commonly used thickeners. Natural and synthetic gums are also used. [Pg.256]

The viscosity of an adhesive directly influences its penetration into a substrate as the viscosity increases, the penetrating power decreases. It also determines the amount of mileage or spread that can be obtained. An optimum viscosity exists for each substrate and each set of machine conditions and must be achieved in order to manufacture an efficient adhesive. Poly(vinyl acetate) emulsions are frequently too low in viscosity to be metered efficiently or to perform well as adhesives by themselves. They must be bodied to working viscosities, eg, by adding thickeners. [Pg.470]

Partially hydrolyzed grades are used in many cosmetic appHcations for their emulsifying, thickening, and film-forming properties. Poly(vinyl alcohol) is also used as a viscosity builder for aqueous solutions and dispersions. [Pg.489]

An example of the first type is the emulsion stabiliser as exemplified by sodium oleyl sulphate, cetyl pyridinium chloride and poly(ethylene oxide) derivatives. For a number of applications it is desirable that the latex be thickened before use, in which case thickening agents such as water-soluble cellulose ethers or certain alginates or methacrylates may be employed. Antifoams such as silicone oils are occasionally required. [Pg.355]

Poly(vinyl alcohol) will function as a non-ionic surface active agent and is used in suspension polymerisation as a protective colloid. In many applications it serves as a binder and thickener is addition to an emulsifying agent. The polymer is also employed in adhesives, binders, paper sizing, paper coatings, textile sizing, ceramics, cosmetics and as a steel quenchant. [Pg.391]

Poly(acrylic acid) is insoluble in its monomer but soluble in water. It does not become thermoplastic when heated. The sodium and ammonium salts have been used as emulsion-thickening agents, in particular for rubber latex. The polymer of methacrylic acid (Figure 15.13 (VI)) is similar in properties. [Pg.423]

The polymers are of interest as water-soluble packaging films for a wide variety of domestic and industrial materials. (Additional advantages of the poly(ethylene oxide)s are that they remain dry to the feel at high humidities and may be heat sealed.) The materials are also of use in a number of solution application such as textile sizes and thickening agents. As a water-soluble film they are competitive with poly(vinyl alcohol) whereas in their solution applications they meet competition from many longer established natural and synthetic water-soluble polymers. [Pg.547]

Analytical A proc is described for the quant titrimetric analysis of TeNMe in nitric acid (Ref 35)s and a spectrophotometric method is described in Ref 41 for the detn of small amts of TeNMe in air and w Critical Diameter. The crit diam for deton propagation of TeNMe thickened with poly-(methyl acrylate) and loaded with up to 75% inert solids was detd and found to decrease with increasing solids loading. It was postulated that the solids acted as reaction foci ahead of the deton front (Ref 45)... [Pg.101]

Pyrogels used by the US armed forces include (1) PT1, which is a complex mixt based on a paste of Mg and an oxidizer, bound with petroleum distillate and asphalt. Isobutyl methacrylate is used as a thickener. (2) PT2, which contains 5% isobutyl methacrylate as a thickener, together with Ba nitrate and a small quantity of asphalt. (3) PTV, which is described as an improved oil and metal incendiary mixt composed of 5% poly butadiene, 6% Na nitrate, 28% Mg, and a trace of p-aminophenol in 60% gasoline (Ref 5)... [Pg.978]

The main polymers used as thickeners are modified celluloses and poly(acrylic acid). Several different modified celluloses are available, including methyl-, hydroxypropyl methyl-, and sodium carboxymethyl-cellulose and their properties vary according to the number and distribution of the substituents and according to relative molar mass of the parent cellulose. Hence a range of materials is available, some of which dissolve more readily than others, and which provide a wide spread of possible solution viscosities. Poly(acrylic acid) is also used as a thickener, and is also available in a range of relative molar masses which give rise to give solutions of different viscosities. [Pg.77]

There are numerous applications where the development of high viscosity is necessary in a finished product. For example, thickeners, mainly based on poly(acrylic acid), are used to give body to so-called emulsion paints. Emulsion paints are not formulated from true emulsions (Le. stable dispersions of organic liquids in water), but are prepared from latexes, that is, dispersions of polymer in water. Since latexes do not contain soluble polymers, they have a viscosity almost the same as pure water. As such, they would not sustain a pigment dispersion, but would allow it to settle they would also fail to flow out adequately when painted on to a surface. Inclusion of a thickener in the formulation gives a paint in which the pigment does not settle out and which can readily be applied by brush to a surface. [Pg.77]

Other uses of thickening agents include pharmaceutical preparations, paper production, and oil well drilling fluids. This latter use is necessary because oil is obtained from rock that is porous. In order to remove the oil without altering the mechanical properties of the porous rock, viscous liquids ( drilling fluids ) are pumped into the rock to replace the oil. Among the substances that can be used for this purpose are thickened aqueous solutions of polymers such as poly(acrylic acid) or poly(acrylonitrile). [Pg.78]

Early soil-release agents, applied particularly to resin-finished cellulosic goods, were water-soluble polymers, many being related to thickeners (section 10.8) such as starch, hydroxypropyl starch, sodium carboxymethylcellulose, methylcellulose, hydroxyethyl-cellulose, alginates, poly(vinyl alcohol) and poly(vinylpyrrolidone). These functioned essentially as temporary barriers and preferential reservoirs for soil, which was thus easily removed along with the finish in subsequent washing, when they then helped to minimise... [Pg.266]

Conversely, vesicants have also been thickened with various substances to enhance deployment, increase their persistency, and increase the risk of percutaneous exposure. Thickeners include polyalkyl methacrylates (methyl, ethyl, butyl, isobutyl), poly(vinyl acetate), polystyrene, plexiglas, alloprene, polychlorinated isoprene, nitrocellulose, as well as bleached montan and lignite waxes. Military thickener K125 is a mixture of methyl, ethyl, and butyl polymethacrylates. When thickened, agents become sticky with a consistency similar to honey. Typically, not enough thickener is added to affect either the color or odor of the agent. [Pg.146]

Poly(ethylene oxide) -- 1931 Thickeners, sizes Poly(butadiene) 1911 1929 Elastomers (number Bunas)... [Pg.9]

The most frequently quoted example to illustrate this behaviour is the children s toy Silly Putty , which is a poly(dimethyl siloxane) polymer. Pulled rapidly it shows brittle fracture like any solid but if pulled slowly it flows as a liquid. The relaxation time for this material is 1 s. After t = 5t the stress will have fallen to 0.7% of its initial value so the material will have effectively forgotten its original shape. That is, one could describe it as having a memory of around 5 s (about that of a mackerel ). Many other materials in common use have relaxation times within an order of magnitude or so of 1 s. Examples are thickened detergents, personal care products and latex paints. This is of course no coincidence, and this timescale is frequently deliberately chosen by formulation adjustments. The reason is that it is in the middle of our,... [Pg.8]

From the viewpoint of sales volume, all other members of the acrylic family constitute a small fraction of the total. However, many of them are useful specialty products. Polyacrylamide (XLIV), poly(acrylic acid) (XLV), and poly(methacrylic acid) (XLVI) and some of their copolymers are used in various applications that take advantage of their solubility in water. Poly(acrylic acid) and poly(methacrylic acid) are used as thickening agents (water... [Pg.308]


See other pages where Poly thickeners is mentioned: [Pg.207]    [Pg.88]    [Pg.248]    [Pg.268]    [Pg.463]    [Pg.487]    [Pg.518]    [Pg.501]    [Pg.47]    [Pg.152]    [Pg.371]    [Pg.278]    [Pg.860]    [Pg.538]    [Pg.517]    [Pg.227]    [Pg.192]    [Pg.193]    [Pg.408]    [Pg.40]    [Pg.40]    [Pg.306]    [Pg.68]    [Pg.124]   


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