Polyacrylate Polymers

Eig. 27. Optical absorption spectra of thin, 1 p.m-films of novolac, polyhydroxystyrene and polyacrylate polymers. The novolac resin is transparent only above 300 nm. While polyhydroxystyrene also absorbs strongly below 300 nm, it exhibits a region of adequate transparency centered near 248 nm. The... 

The effect of pH on both clay swelling and fines production has been widely discussed(89-95). Little consensus is found in this literature. Suggested treatments range from application of fluoboric acid(96) to 15% KOH(92) solutions — both treatments are believed to create a protective silicate film that inhibits release of fines. Polyacrylate polymers can provide protection against swelling of smectite clays and shales(97-100). 

Calculate the mass of water that was absorbed by the sodium polyacrylate polymer. (Note 1 mL of water = 1 g)... 

Use the mass of the sodium polyacrylate polymer and the mass of the water it absorbed to calculate the mass/mass ratio of the polymer to water. 

What practical applications might the sodium polyacrylate polymer be used for ... 

The various types of polyacrylate polymers are manufactured from the relevant monomers by a free radical mechanism using peroxide initiators and can be block or random polymers depending on the degree of prepolymerization of the monomers used. 

Polyacrylate-polymethacrylate copolymers (Eudragits) are widely used as tablet adjuvants and coating polymers [1]. These polyacrylate polymers were also used for the microencapsulation of... 

The use of an electric field is not the only effective way to influence the LC polymer structure, magnetic fields displays a closely similar effect167 168). It is interesting as a method allowing to orient LC polymers, as well as from the viewpoint of determining some parameters, such as the order parameter, values of magnetic susceptibility, rotational viscosity and others. Some relationships established for LC polymer 1 (Table 15), its blends with low-molecular liquid crystals and partially deuterated polyacrylate (polymer 4, Table 15) specially synthesized for NMR studies can be summarized as follows ... 

In addition to forming the chains of polyacrylate, the chains are cross-linked. This is a process in which two or more chains are held together by other compounds in a network. Typical cross-linkers for this polymer include di- and tri-acrylate esters. The swelling and elasticity of the polyacrylate polymer depends on the structure of this network and the number of cross-links. The swelling capacity of the polymer decreases with increased cross-link density. After formation, the polyacrylate is dried and formed into microparticles of irregular shape that can be stored for a long time. 

Gressel and Roehrs reported viscosity modifiers for enhancing intended effects on an ocular surface. A polyacrylic polymer was used to increase viscosity to a gel consistency and thereby enhancing the treatment of symptoms for dry eyes. Sullivan reported efficacy of carbomer gel in improving the number of subjective and objective symptoms of moderate-to-severe dry eye syndromes. Such a gel vehicle offered an advantage of reducing frequency of instillation and has resulted in a commercial product (Pilopine HS Gel). 

Several fiber coatings have been investigated. The most successful phase has been polydimethylsiloxane (PDMS), which is available commercially from several optical fiber manufacturers or from Supelco in thicknesses ranging from 7 to 100 pm (Arthur et al., 1992 Supelco Catalog, see Appendix). A second coating that is proving useful is a polyacrylate polymer for phenols and chlorinated phenols (Bucholz and Pawliszyn, 1993). 

A route taking advantage of the electrophilicity of the pyridyl N-oxide functionahty was reported by Smith et al. [386]. The authors used a polyacrylate polymer, which was terminally chlorinated with SOCI2 and then reacted with 2-chloropyridine N-oxide. The very unstable support-linked chloropyridinium species was claimed to react with the enamine. After acidolysis of the imine and basic hydrolysis of the N-oxyester, 2(6-chloro-2-pyridyl)cyclohexanone was obtained. 

Thickening agent Polyacrylate polymer, clay, alumina 0-10... 

The polyacrylate polymers and a derivative of a vinyl acetate maleic anhydride copolymer cause V30 to decrease monotonically with increasing polymer concentration, similar to the CMC polymers (Figure 46). The polymers PVA and poly(vinyl pyridinium) (PVP) hydrochloride markedly increased V30 at low concentration at concentrations above 1 g of polymer per gram of added bentonite PVA functions as a static fluid loss additive. The maximum in the API fluid loss at low PVA concentrations approximately coincides with the maximum in the yield stress and plastic viscosity found by Heath and Tadros (75). The increased static fluid loss is consistent with Heath and Tadros s conclusion that bentonite is flocculated by low concentrations of PVA. The concentration of PVA required to decrease V30 below that of the neat bentonite suspension is significantly larger than the concentration of CMC, where effective static fluid loss control can be achieved at polymer bentonite weight ratios of about 0.1 g/g. More effective fluid loss control has been achieved with other synthetic polymers such as poly(vinyl sulphonate)-poly(vinyl amide) copolymer (40) and other sulphonated polymers (39). 

Add the low molecular weight polyacrylate polymer followed by the sodium hydroxide and sodium silicate. Mix until homogeneous. 

Chem. Desaip. Ammonium salt of polyacrylate polymer (aq.)... 

Cbem. Descrip. Sodium salt of polyacrylate polymer CAS 90034)4-7... 

Fig. 1.16 Microscopic image of a mixture of monodisperse polystyrene latex particles 25 min (top) and 55 min (bottom) after adding 185 mg/L sodium polyacrylate polymers. Picture reprinted from A. Kose and S. Hachisu,...

The advent of water-soluble polymers with well-defined hydrophobic centers, such as dodecyl or nonylphenyl side chains (or even pyrene groups), has continued to formalize the concept of a relationship between the hydrophobicity of a polymer and its reactivity. As mentioned earlier, reactivity in a series of alkyl-substituted polyacrylate polymers was shown, in the fluorescence measurements of Magny et al. (90,114), to correlate with the number and chain length of the substituent groups, as was the case for alkyl-substituted maleic anhydride copolymers (115). It is easy to understand that hydrophobicity introduced in this way can lead to interaction through the formation of mixed micelles with the surfactant. (See Fig. 22.) Indeed, as we have pointed out, the interaction affinity in some cases can be so large as to overcome unfavorable electrostatic forces. 

Viscosity increases and gel formation in polyanion-cationic surfactant systems have also been reported, for example by Thalberg and Lindman (86) for hyaluronan and polyacrylate polymers in combination with alkyltrimethylammononium bromide surfactants. Similarly, viscosity increases and gel formation with polymers such as carboxymethyl cellulose (CMC) and CTAB at relatively low polymer-surfactant levels have been observed (87). 

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