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Acrylic acid basic

Following a brief review of the development of dynamic membranes and an overview of the current state of the art, Spencer (10) discusses dynamic polyblend membranes. In particular, he looks at the Influence that polymer selection and membrane preparation procedures have on membrane performance. Dynamic membranes composed of a poly(acrylic acid)/basic polyamine blend deposited on a ZOSS (hydrous zirconium oxide on stainless steel) ultrafiltration membrane are discussed. Their hyperfiltration or reverse osmosis properties are compared to the more traditional ZOPA (zirconium oxide plus poly(acrylic acid)) membrane. [Pg.17]

Copolymers can be used to introduce a mixture of chemical functionalities into a polymer. Acidic and basic substituents can be introduced, for example, through comonomers like acrylic acid and vinyl pyridine. The resulting copolymers show interesting amphoteric behavior, reversing their charge in solution with changes of pH. [Pg.469]

Amino groups on azolium rings can lose a proton to form strongly basic azolinimines, e.g. (445) yields (446). 2-Iminobenzothiazoline with acrylic acid yields (447). [Pg.97]

In September 1964 the Du Pont company announced materials that had characteristics of both thermoplastics and thermosetting materials. These materials, known as ionomers, are prepared by copolymerising ethylene with a small amount (1-10 % in the basic patent) of an unsaturated carboxylic acid such as acrylic acid using the high-pressure process. Such copolymers are then treated... [Pg.277]

In the case of electron-deficient monomers (e.g, acrylics) it is accepted that reaction occurs by initial addition of the sulfate radical anion to the monomer. Reactions of sulfate radical anion with acrylic acid derivatives have been shown to give rise to the sulfate adduct under neutral or basic conditions but under acidic conditions give the radical cation probahly by an addition-elimination process. [Pg.129]

Applications As the basic process of electron transfer at an electrode is a fundamental electrochemical principle, polarography can widely be applied. Polarography can be used to determine electroreductible substances such as monomers, organic peroxides, accelerators and antioxidants in solvent extracts of polymers. Residual amounts of monomers remain in manufactured batches of (co)polymers. For food-packaging applications, it is necessary to ensure that the content of such monomers is below regulated level. Polarography has been used for a variety of monomers (styrene, a-methylstyrene, acrylic acid, acrylamide, acrylonitrile, methylmethacrylate) in... [Pg.671]

We make polyethylene resins using two basic types of chain growth reaction free radical polymerization and coordination catalysis. We use free radical polymerization to make low density polyethylene, ethylene-vinyl ester copolymers, and the ethylene-acrylic acid copolymer precursors for ethylene ionomers. We employ coordination catalysts to make high density polyethylene, linear low density polyethylene, and very low density polyethylene. [Pg.288]

Depolymerised Carpet printing/dyeing acid, metal-complex dyes Cotton, viscose vat, direct, azoic dyes Polyester disperse dyes Nylon acid, metal-complex dyes Acrylic fibres basic dyes... [Pg.189]

Types of compounds are arranged according to the following system hydrocarbons and basic heterocycles hydroxy compounds and their ethers mercapto compounds, sulfides, disulfides, sulfoxides and sulfones, sulfenic, sulfinic and sulfonic acids and their derivatives amines, hydroxylamines, hydrazines, hydrazo and azo compounds carbonyl compounds and their functional derivatives carboxylic acids and their functional derivatives and organometallics. In each chapter, halogen, nitroso, nitro, diazo and azido compounds follow the parent compounds as their substitution derivatives. More detail is indicated in the table of contents. In polyfunctional derivatives reduction of a particular function is mentioned in the place of the highest functionality. Reduction of acrylic acid, for example, is described in the chapter on acids rather than functionalized ethylene, and reduction of ethyl acetoacetate is discussed in the chapter on esters rather than in the chapter on ketones. [Pg.321]

The same phenomenon is responsible for the decrease in the ionization constant of a polymeric acid such as poly(acrylic acid) with increasing degree of ionization [Kawaguchi et al., 1990, 1992 Morawetz and Wang, 1987]. This effect is somewhat moderated for acrylic acid-ethylene copolymers, since charge density on the ionized polymer is decreased. The basicity... [Pg.734]

Glass-ionomers have been used in various areas of restorative dentistry since the mid 1970s. They were invented and originally described by Wilson and Kent [208], and consist of a basic glass powder and a water-soluble acidic polymer. The most widely used polymer is poly(acrylic acid), but acrylic/maleic acid copolymer is also widely used [209]. The glass powder is a complex calcium (or strontium) aluminofluorosilicate [210] that is typically at least partially phase separated. [Pg.356]

Novel responsive controlled release systems based upon polyelectrolyte-grafted membranes have also been reported. Iwata and Matsuda prepared novel environmentally sensitive membranes by grafting poly(acrylic acid) onto poly(vinylidene fluoride) membranes [382, 383]. Under basic conditions, the... [Pg.32]

For example, an aqueous suspension homopolymerization would normally not be appropriate for water-soluble monomers such as acrylamide or acrylic acid. For such cases, it may be possible that with high levels of neutral salts, the water solubility of such monomers may be reduced to permit the use of suspension polymerization techniques. Other monomers may have other unique properties that require some modifications of the basic procedures. [Pg.71]

The one-stage conversion of propene to acrylic acid is much more difficult than the selective production of acrolein. The process is essentially a two-step process in which acrolein is the intermediate product. Further oxidation leads to acrylic acid. In fact, contrasting catalyst properties are required for these reaction steps. The acrylic acid production demands an acidic catalyst surface, while a basic, or only weakly acidic character is preferred for the selective acrolein formation. Therefore, enhanced combustion and by-product formation are unavoidable. [Pg.159]

Considerable evidence exists indicating that the acidity of an oxide surface can vary according to the pretreatment. For example, Finlayson and Shah [12] used flow microcalorimetry to characterize the oxidized surfaces of three aluminum specimens that had received different pretreatments. They found that the surface chemistry of the three samples was considerably different but was dominated by Lewis base sites in all cases. The peel strength of ethylene/acrylic acid copolymers laminated against the substrates increased as the basicity of the substrate and the acrylic acid content of the co-polymer increased. [Pg.244]

The SDA gave the technical expertise to several USA companies for further development of the basic technology. A wide range of grating combinations was attempted including work with acrylic acid, acrylamide, and polyvinyl alcohol (PVA). [Pg.33]


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See also in sourсe #XX -- [ Pg.509 ]




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