Synthetic polymers polyacrylamides

Synthetic polymers and natural polymers suitable for drilling muds are listed in Tables 1-7 and 1-8, respectively. Polyacrylamides are eventually hydrolyzed in the course of time and temperature. This leads to a lack of tolerance toward electrolyte contamination and to a rapid degradation inducing a loss of their properties. Modifications of polyacrylamide structures have been proposed to postpone their thermal stability to higher temperatures. Monomers such as AMPS or sulfonated styrene/maleic anhydride can be used to prevent acrylamide comonomer from hydrolysis [92]. 

Many synthetic water-soluble polymers are easily analyzed by GPC. These include polyacrylamide,130 sodium poly(styrenesulfonate),131 and poly (2-vinyl pyridine).132 An important issue in aqueous GPC of synthetic polymers is the effect of solvent conditions on hydrodynamic volume and therefore retention. Ion inclusion and ion exclusion effects may also be important. In one interesting case, samples of polyacrylamide in which the amide side chain was partially hydrolyzed to generate a random copolymer of acrylic acid and acrylamide exhibited pH-dependent GPC fractionation.130 At a pH so low that the side chain would be expected to be protonated, hydrolyzed samples eluted later than untreated samples, perhaps suggesting intramolecular hydrogen bonding. At neutral pH, the hydrolyzed samples eluted earlier than untreated samples, an effect that was ascribed to enlargement... 

Synthetic Petroleum based Acrylic acid polymers Polyacrylamides Alkylene/alkylene... 

Dry strength additives are usually water soluble, hydrophilic natural or synthetic polymers, the commercially most important of which are starch, natural vegetable gums and polyacrylamides. These polymers are often made in cationic form by the introduction of tertiary or quaternary amino groups into the polymer, and are therefore polyelectrolytes. They are thus also able to function to some extent as drainage and retention aids. 

Enzymes can be immobilized by matrix entrapment, by microencapsulation, by physical or ionic adsorption, by covalent binding to organic or inorganic polymer-carriers, or by whole cell immobilization (5 ). Particularly impressive is the great number of chemical reactions developed for the covalent binding of enzymes to inorganic carriers such as glass, to natural polymers such as cellulose or Sepharose, and to synthetic polymers such as nylon, polyacrylamide, and other vinyl polymers and... 

One of the extensively used synthetic polymers used as a support for immobilization of biocatalysts is polyacrylamide (PAAm) [287,288], The major advantage is that it can be polymerized either chemically or by using radiation. Advantages of y-ray polymerization against chemical polymerization is that the polymerization can be carried out even under frozen conditions thus allowing the matrix to be molded to any form such as beads or membranes [289-291], However one of the major drawbacks of this polymer especially in a membranous form is its brittleness. 

Synthetic polymers This type of chiral selectors (polyacrylamides, polymethacrylamide, etc.) was first developed by the group of Blaschke by polymerization of chiral monomers with cross-linking agents to form a three-dimensional polymer network. 

The use of PCA for the classification of both natural and synthetic polymers was demonstrated by Vazquez et al. [119]. In their work, the researchers recorded Totai X-Ray Fluorescence (TXRF) spectra of scleroglucan, xanthan, glucomannan, poly(ethylene oxide), and polyacrylamide and subjected the resulting spectral data to PCA. To the naked eye, the X-ray fluorescence spectra of the polymers look virtually identical. However, when subjected to PCA it could be shown that the first two principal components contain approximately 96% of the variance in the dataset. When plotting the scores of the two components against each other, six distinct clusters are observed, which clearly differentiate the individual polymers. 

Thus one might expect flexible, water-soluble synthetic polymers with suitable side chains to show strong affinities for small molecules. In the course of 20 years we examined the binding ability of polyvinylpyrrolidone, polyvinylpyridine, polylysine, polyacrylamide, polyisopro-pylacrylamide, polyvinylimidazole, polyvinylmethyloxazolidinone,... 

Synthetic water treatment polymers were first introduced in the 1950s. The first important synthetic polymers included hydrolyzed polyacrylamide and various high molecular weight (100,000+) homopolymers of polyacrylic acid and polymethacrylic acid, together with their sodium salts. 

Synthetic polymers polyolefines (polystyrene, polystyrenedivinylben-zene), acrylic polymers (polyacrylate, polyacrylamide, polymethacrylate, etc.) and others such as polyvinyl alcohols, polyvinyl chloride, polyte-trafluoroethylene, polyamides, polyurethane, silicone, etc. 

Thus one might expect flexible, water-soluble synthetic polymers with suitable side chains to show affinities for small molecules. We have examined, over several decades, the binding ability of poly(vinylpyrrolidone), polyvinylpyridine, polylysine, polyacrylamide, poly(isopropylacrylamide), poly(vinylimidazole), poly(vinylmethyloxazolidi-none), poly(vinylmethyloxazolidinone-vinylimidazole), poly(vinylpyrrolidone-vinyli-midazole), poly(vinylpyrrolidone-vinyl alcohol), poly(vinylpyrrolidone-maleic anhydride), poly(vinylmethyloxazolidinone-maleic anhydride), and poly(2-methylami-noethyl methylacrylate-methacrylic acid). Other investigators have studied similar synthetic polymers [5-12], In our experience no water-soluble polymer binds small molecules with an avidity comparable to serum albumin. 

Although S-FFF is usually applied to particles or large biopolymers, its use for the analysis of synthetic polymers with high molecular weight (M) was demonstrated for polyacrylamide [176]. This is, however, a rare application. 

An ideal matrix for gel filtration should consist of partides of a hydrophilic polymer, that is as inert as possible, as rigid as possible, uncharged, and of uniform size (Patel 1993). Suitable materials are naturally occurring polymers, such as agarose or dextran, which have been stabilised by chemical cross linking, and also synthetic polymers such as polyacrylamide. These materials are available as spherical partides of different diameter (10-500 pm) and pore sizes the pore size determines the range of optimal molecular weight separation (Table 4-1). 

A CSP consists of a chiral selector, which either alone constitutes the stationary phase or which has been immobilised to a solid phase. The chiral selector is a low molecular weight compound or a polymer, either synthetic or natural. A broad range of CSPs has been developed. Examples of CSPs that have been used successfully include polysaccharides, such as cellulose and its derivatives [6] and cyclodex-trins [7], and proteins, e.g. bovine serum albumin, aj-acid glycoprotein, cellulase, trypsin and a-chymotrypsin [8]. Several different synthetic polymers have also proven to be useful CSPs, for example the Blaschke-type CSPs (polyacrylamides and polymethacrylamides) [9] and the Pirkle-type CSPs [10]. 

Aqueous SEC. A number of synthetic polymers require the use of aqueous based mobile phase systems for separation/characterisation. These inelude polyacrylamides, polyvinyl alcohols, poly(sodium vinyl... 

In contrast to agarose, polyacrylamide is a synthetic polymer, and gel formation depends on chemical cross-linking. The bifunctional acrylamide derivative, N,N -methylene-6is-acrylamide is included in the polymerisation mixture to insert cross-links between chains of... 

Scmi-synthctic and synthetic polymers are also used as thickening agents. Such are carboxymethyl cellulose [87,6] and polyacrylamide [73] respectively. 

The two main types of polymers are synthetic polymers snch as hydrolyzed polyacrylamide (HPAM) and biopolymers such as xanthan gum. Less commonly used are natural polymers and their derivatives, snch as gnar gnm, sodium carboxymethyl cellulose, and hydroxyl ethyl cellnlose (HEC). Table 5.1 summarizes the characteristics of different polymer stmctnres. 

Gel chromatography may prove useful for the separation of biomacromolecules at different degrees of polymerization, as is the case with synthetic polymers for example, Nakasaki et al. [89] purified alkaline phosphatase from rat small gut. One of the purification steps was gel chromatography on a porous glass column-filling material which resulted in separation of the enzymatic activity into three fractions. Further analysis of the fractions by polyacrylamide gel electrophoresis in the... 

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