설명(영) |
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Synthetic polymers are the large molecules prepared from relatively small chemical compounds called monomers. If only one monomer is used in the synthesis, the resulting polymer is a homopolymer. So-called copolymers result whenever two or more monomeric molecules are employed in the synthesis. If the monomers are blended during synthesis, random polymers result, e.g., as from mixtures of ethylene and propylene oxides. If ester or amide links are formed during polymerization, the specifics of the chemical reaction control the structure of the final polymer, e.g., Nylon. Block copolymers are prepared by first forming a homopolymer and then reacting this with a different monomer; the reactive groups of this polymer can then be further reacted with additional monomeric reagents. Cross-linked polymers are commonly formed during the synthesis of homo- or copolymers when the monomeric constituents are multifunctional.
The molecular weight of polymers varies greatly. Polymers may be brittle solids, like Tosylamide/Formaldehyde Resin; flexible solids, like nylon or polyethylene; or liquids of varying viscosities, such as Polybutene. Polymers may be water soluble, such as PVP, or almost unaffected by any solvent, such as Polychlorotrifluoroethylene. In light of the wide variety of polymers available, these materials have found uses in numerous cosmetic products for a multitude of purposes. Today synthetic polymers are commonly used as the primary constitutuents of hair sprays and nail enamels, as film formers in skin and makeup products, and as viscosity builders of water-based and oil-based types of products. Biological Polymers and their derivatives and certain Waxes can also perform similar functions in finished cosmetic products. |