Polymer water soluble

Hydrophilic Groups. Water solubiUty can be achieved through hydrophilic units in the backbone of a polymer, such as O and N atoms that supply lonepair electrons for hydrogen bonding to water. SolubiUty in water is also achieved with hydrophilic side groups (eg, OH, NH2, CO2, SO3 ). 

These groups are found in the various polymers discussed here. Truly unique in its abiUty to interact and promote water solubiUty is the —O—CH2—CH2— group. The interactions of these groups with water and their placement in the polymer stmcture influence the water solubiUty of the polymer and its hydrodynamic volume. 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Commercial Derivatization of Cellulose. Cellulose, the world s most abundant polymer, is derivatized for use in a variety of markets. 

Commercial Derivatization of Cellulose. Cellulose, the world s most abundant polymer, is derivatized for use in a variety of markets. Two important classes are cellulose esters (qv) and cellulose ethers (qv). Cellulose esters are not water soluble and are not discussed here cellulose ethers are an important segment of water-soluble polymers. 

A number of synthetic polymers that are widely used commercially are soluble in water. These tend to have very polar functional groups and include such polymers as poly(vinyl alcohol), poly(acrylic acid), and the modified celluloses. 

Mere possession of polar functional groups is not, by itself, enough to confer water-solubility. Poly(vinyl alcohol), which is prepared by the hydrolysis of poly (vinyl ethanoate), is only soluble if a few ethanoate groups are left 

In the case of water-soluble polymers, there is another factor that has to be taken into account when considering solubility, namely the possibility of hydrophobic interactions. If we consider a polymer, even one that is soluble in water, we notice that it is made up of two types of chemical species, the polar functional groups and the non-polar backbone. Typically, polymers have an organic backbone that consists of C—C chains with the majority of valence sites on the carbon atoms occupied by hydrogen atoms. In other words, this kind of polymer partially exhibits the nature of a hydrocarbon, and as such resists dissolution in water. 

Hydrophobic interactions of this kind have been assumed to originate because the attempt to dissolve the hydrocarbon component causes the development of cage structures of hydrogen-bonded water molecules around the non-polar solute. This increase in the regularity of the solvent would result in an overall reduction in entropy of the system, and therefore is not favoured. Hydrophobic effects of this kind are significant in solutions of all water-soluble polymers except poly(acrylic acid) and poly(acrylamide), where large heats of solution of the polar groups swamp the effect. 

Mere possession of polar functional groups is not, by itself, enough to confer water-solubility. Poly(vinyl alcohol), which 

The previous two sections reviewed characteristics of polymers that, in general, are not soluble in water and, therefore, are typically used as solid materials fibers, matrices, microspheres, or foams. Water-soluble polymers are also useful as biomaterials. Water-soluble polymers can be used in their molecular, water-soluble form as agents to modify other materials or as solid, dissolvable matrices (see the example of copolymers of methyl vinyl ether and maleic anhydride in Section A.2.2). Alternatively, water-soluble polymers may be cross-linked, by chemical or physical means, into solid materials (gels) that swell in water but do not dissolve. 

These polymers are used in a variety of household goods (detergents, toothpaste, shampoo, skin lotions, and conditioners) and industrial goods (flocculants, thickeners, and emulsifiers). These polymers are largely anionic or nonionic in character and assist in reducing slurry viscosity, and improve dispersion and anti-redeposition. There is a widespread misconception that because these polymers are water soluble they do not contribute to pollution. Neither are all 

The velocity of penetration (S) of a solvent into the bulk polymer obeys the relationship 

The solubility of polymeric substances in water is determined by the same considerations that apply to smaller molecules. Those polymers that are sufficiently polar will be able to interact with the water to provide energy to remove individual polymer chains from the solid state. 

Water-soluble polymers have an ability to increase the viscosity of solvents at low concentrations, to swell or change shape in solution, and to adsorb at surfaces. These are significant features of their behaviour, which we will deal with briefly. 

Insoluble polymers or polymers with a low rate of solution are used more to form thin films, as film-coating materials, surgical dressings or membranes for dialysis or filtration or to form matrices for enveloping dmgs to control their release properties or simply as packaging materials. 

It is the combination of slow solution rate and the formation of viscous surface layers that makes hydrophilic polymers useful in controlling the release rate of soluble dmgs which are perhaps irritant to the stomach or which cause nausea on rapid release (see section 8.5). Choice of appropriate polymer molecular weight controls both the rate of dissolution and the viscosity of its resulting solution. A balance between rate of polymer solution and viscosity of the solution layer must be achieved in controlled-release systems. If the polymer solution rate is too slow, then soluble dmg is leached out with little retardation. 

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Goddard G D 1986 Polymer-surfaotant interaotion. Part 1. Unoharged water-soluble polymers and oharged surfaotants Colloid Surf. 19 255-300... 

Cabane B and Dupplessix R 1985 Neutron soattering study of water-soluble polymers adsorbed on surfaotant mioelles Colloids Surf. 13 19-33... 

Poly(vinyl alcohol) is a useful water soluble polymer It cannot be prepared directly from vinyl alcohol because of the rapidity with which vinyl alcohol (H2C=CHOH) isomenzes to acetaldehyde Vinyl acetate however does not rearrange and can be polymerized to poly(vinyl acetate) How could you make use of this fact to prepare poly(vinyl alcohol)" ... 

Polylacrylic Acid) and Poly(methacrylic Acid). Glacial acrylic acid and glacial meth-acrylic acid can be polymerized to produce water-soluble polymers having the following structures ... 

POWDERS,HANDLING - DISPERSION OF POWDERS IN LIQUIDS] (Vol 19) Cationic water-soluble polymers... 

Water solubility Water-soluble fluxes Water-soluble polymers... 

Dichromated Resists. The first compositions widely used as photoresists combine a photosensitive dichromate salt (usually ammonium dichromate) with a water-soluble polymer of biologic origin such as gelatin, egg albumin (proteins), or gum arabic (a starch). Later, synthetic polymers such as poly(vinyl alcohol) also were used (11,12). Irradiation with uv light (X in the range of 360—380 nm using, for example, a carbon arc lamp) leads to photoinitiated oxidation of the polymer and reduction of dichromate to Ct(III). The photoinduced chemistry renders exposed areas insoluble in aqueous developing solutions. The photochemical mechanism of dichromate sensitization of PVA (summarized in Fig. 3) has been studied in detail (13). 

With the proper ratio of nutrients and oxygen feed, a water-soluble polymer is produced and accompanied by growth in the microorganism population. Both contribute to the viscosity of the medium and this limits the production process. Fermentation processes require more strenuous mixing and control conditions. 

Cationic monomers are used to enhance adsorption on waste soHds and faciHtate flocculation (31). One of the first used in water treatment processes (10) is obtained by the cyclization of dimethyldiallylammonium chloride in 60—70 wt % aqueous solution (43) (see Water). Another cationic water-soluble polymer, poly(dimethylarnine-fi9-epichlorohydrin) (11), prepared by the step-growth... 

The Hterature on the preparation and appHcation of numerous synthetic cationic quaternary water-soluble polymers has been reviewed in detail (46). 

Two inorganic water-soluble polymers, both polyelectrolytes in their sodium salt forms, have been known for some time poly(phosphoric acid) (12) and poly(siHcic acid) (13). A more exciting inorganic water-soluble polymer with nonionic... 

A. E. Broderick (Union Carbide). HEC did not become a viable commercial product until the early 1960s. In addition to the general production problems and market development costs, new products face a variety of environmental controls in the 1990s that add more constraints to market development. None the less two more recentiy developed water-soluble polymers have achieved limited market acceptance and are described below. 

Minimization of the elastic behavior of the fluid at high deformation rates that are present when high molecular weight water-soluble polymers are used to obtain cost-efficient viscosities at low shear rates. 

Providing coUoidal stabiHty to disperse phases in aqueous media, not achievable with traditional water-soluble polymers. 

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