Acrylic acid Industry characteristics

Industrial needs for brighter phosphors in the form of well-dispersed finer particles are ever increasing, for display with higher resolution. This became realistic after the reports of Bhargava et al. (12,13). In the authors laboratory, ZnS Mn was modified by acrylic acid (AA) to increase the photoluminescence (PL) intensity (14-18). In this section, methods and characteristic features of such nanocomposites are reproduced in detail. The mechanism of increasing PL intensity is also elucidated from various angles. 

In many cases latex products are composed of more than one monomer. In copolymerisation two or more monomers are built-in into the polymer chains. The copolymer chains are produced by simultaneous polymerisation of two or more monomers in emulsion. Emulsion copolymerisation allows the production of materials with properties which cannot be obtained by latex products consisting of one monomer, that is, homopolymer latexes, or by blending homopolymers. The properties of the materials required are usually dictated by the market. Nowadays, most of the material properties are achieved by combination of more than two monomers in the copolymer product. Typical industrial emulsion polymerisation formulations are mixtures of monomers giving hard polymers, and monomers leading to soft polymers. Styrene and methyl methacrylate are examples of monomers giving hard polymers, that is, polymers with a high glass transition temperature, Tg. Soft polymers, that is, polymers with a low Tg, are, for example, formed from -butyl acrylate. The industrial emulsion polymerisation formulations also contain small amounts of functional monomers such as acrylic and methacrylic acid to impart improved or special characteristics to the latex product. Note that the colloidal stability of the latex product can be seriously improved by acrylic and methacrylic acid. Furthermore, some applications may demand for the addition of other specialty monomers that make the kinetics of the copolymerisation even more complex. 

Hydrophobe-modified copolymers of acrylate esters with acryflc or methacryflc acid are finding increasing use as high quality thickeners for both trade sales and industrial paints (186). Formulations thickened with these unique water-soluble polymers show excellent flow and leveling characteristics. 

There are many types of waterborne laminating adhesives with widely differing applications and performance properties. Common waterborne textile adhesives include natural rubber latex, co-polymers of acrylic esters and acids, vinyl and vinylidene chloride, vinyl acetate, and chloroprene. Other, less common adhesives include starches, dextrin, and other polymers of natural origin. Characteristics of common waterborne adhesive used by the textile industry are given in Table 13.11. 

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