Cationic acrylic polymers

Highly branched ethene-methyl acrylate polymers. The cationic palladium diimine complexes are remarkably tolerant towards functional groups, although the rates decrease somewhat when polar molecules are added. In ETM catalysis addition of polar molecules or monomers kills the catalyst and therefore it was very interesting to see what the new palladium catalysts would do in the presence of polar monomers. Indeed, using methyl acrylate a copolymerisation... 

Sherrington and coworkers161 have examined the chlorination of phenol by J-butyl hypochlorite in the presence of cross-linked polystyrenes substituted by pendant polymethylene chains terminated with anionic or cationic head groups, as well as some hydrophilic acrylic polymers, in four solvents water, methanol, 1,2-dichloroethane and xylene. The polymers exerted a significant influence on the chlorination, particularly in polar solvents. However, no changes in the regioselectivity of the chlorination, in comparison to homogeneous systems, was observed. 

Of the various approaches taken while using a bi-component ink system, this is the most common one as reflected in the patent ht-erature (see Fig. 12). This system is based on the fact that several polymers are soluble in aqueous solution under certain conditions (e.g., pH value, presence or absence of metal ions) and will precipitate as soon as the chemical environment in the ink is changed. An acrylic polymer will be soluble in the ink at an elevated pH, hence it will instantaneously precipitate upon its reaction with a polyvalent cation which is present at the surface of the substrate. The result of this reaction will be a gelled ink droplet which will be practically immobilized. The schematic reaction mechanism is shown in Fig. 13. 

Analytical Methods. Historically, the copolymer composition of cationic acrylic polymers has been measured by conductiometric (28), silver nitrate (29), or colloid titration (52, 53). Chromatographic methods have been reported for acrylamide monomer (54-56) however, no such methods have been employed for quaternary ammonium monomers. In this chapter, a new HPLC method (Nalco) is described for the simultaneous determination of both comonomers. Colloid titration is described in the next paragraph and was used only for comparison purposes. 

The high affinity of Pd-chloro-complexes to strong anion exchange materials enables the use of various anion exchange sorbents for preconcentration of Pd with simultaneous elimination of cationic interferents. Especially styrene or acrylic polymers cross-linked with divinylbenezene can be applied for enrichment of PGE from large sample volumes (Matsubara et al. 2000 Kovacheva and Djingova 2002 Lesniewska et al. 2006). 

Although in pxinciple associative thickenos could be prepared from any water-soluble polymer to which hydrophobic blocks can be attached, only three types are commercially available at present hydrophobe-modified polyfetl lene oxide), hydrophobe-modified alkali-soluble acrylic polymers, and hydrophobe-modified hydroxyethyl cellulose. However, the literature contains reports on other types, including hydrophobe-modified polyacrylamide [103], hydrophobe-modified hydroxypropyl guar [104], and a hydrophobe-modified cationic cellulose... 

The acrylic monomers that make up cationic polymers are usually the same as those that make up anionic polymers (Table 2.1). Cationic acrylic polymers contain a basic ionizable group, which is usually introduced in one of two ways. The most common method is copolymerization of monomers with an amine group containing monomer, such as dimethylaminoethyl methacrylate (DMAEMA, Fig. 2.6). 

The alternative method is to preform a copolymer that includes a reactive site capable of being attacked by a nucleophile, such as an epoxide group. In this case, the nucelophile is an amine, such as N-methylethanolamine. Table 2.3 gives typical examples of cationic acrylic polymers along with the type of resist in which they are used. 

Basic dyes are applied from weakly acidic dyebaths and are used to dye acrylic and cationic dyeable polyester. The cationic positively charged portion of the dye molecule in solution aligns with an anionic, negative charged site on the fiber that the fiber manufacturers include in the polymer. The ionic bonding that occurs is the result of the anionic dyesite forming ion pairs with the quaternary amine group present as part of the dye molecule (Fiber-R NH3-Dye). 

Cationic surfactants are not often used in emulsion polymerisation of acrylic polymers for surface coating applications. 

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