Vinyl chloride copolymers, extraction

Diisobutyl ketone is used as a high boiler in cellulose nitrate lacquers. It acts as a leveling agent and has outstanding properties as a solvent for cellulose nitrate emulsion lacquers used to coat leather. Diisobutyl ketone is used as a solvent for vinyl chloride copolymers and as a dispersant for poly(vinyl chloride) organosols. It also serves as an extracting agent and feedstock for chemical syntheses. 

Methylal [109-87-5] (formaldehyde dimethyl acetal, dimethoxymethane) is a pleasantly smelling, extremely volatile solvent. It dissolves polystyrene, polyfvinyl acetate), vinyl chloride copolymers, acrylates, methacrylates, and synthetic and natural resins. It is used in paints and lacquers, adhesives, and aerosols. Important extracting agent for natural substances, essences, and oils. It serves as a reaction medium in the chemical industry and as an intermediate for chemical syntheses. 

N-Methylpyrrolidone [872-50-4] (NMP) has a fairly mild, amine-like odor, and is miscible with water and most organic solvents. It has a good solvency for cellulose ethers, butadiene-acrylonitrile copolymers, polyamides, polyacrylonitrile, waxes, polyacrylates, vinyl chloride copolymers, and epoxy resins. It is used in paint removers and stripping paints to reduce paint viscosity, and to improve the wettability of paint systems. A -Methylpyrrolidone is also employed for the extraction of hydrocarbons, and as a solvent in the synthesis of acetylene. 

Grafted samples were prepared by dissolving the EVA copolymer in vinyl chloride, followed by suspension polymerization. In moderately grafted samples, some pure EVA remained. In strongly grafted samples no pure EVA could be extracted. 

Materials. Ethylene-propylene copolymer, purified by Kumagawa (9) acetone extraction for 180 hours had a composition (determined by infrared) of C2 — 54.5, C3 = 45.5 wt %, and an intrinsic viscosity determined in toluene at 30°C of 1.38 X 10 cc/gram. Poly (vinyl alcohol) was Elvanol 50-42 from du Pont. The vinyl chloride monomer of Monte-catini Edison was 99.99% pure. Initiators used were ... 

As shown in Figure 1.17, there are three possible dichloroethylene compounds, all clear, colorless liquids. Vinylidene chloride forms a copolymer with vinyl chloride used in some kinds of coating materials. The geometrically isomeric 1,2-dichloroethylenes are used as organic synthesis intermediates and as solvents. Trichloroethylene is a clear, colorless, nonflammable, volatile liquid. It is an excellent degreasing and dry-cleaning solvent and has been used as a household solvent and for food extraction (for example, in decaffeination of coffee). Colorless, nonflammable liquid tetrachloroethylene has properties and uses similar to those of trichloroethylene. Hexachloro-butadiene, a colorless liquid with an odor somewhat like that of turpentine, is used as a solvent for higher hydrocarbons and elastomers, as a hydraulic fluid, in transformers, and for heat transfer. 

Di(2-ethylhexyl) azelate n. (dioctyl azelate, DOZ) (CH2)7[C00CH2-CH(C2H5) QH9]2. a plasticizer for vinyl chloride polymers and copolymers. It is one of the most compatible of the low-temperature, monomeric plasticizers, has low volatility, and imparts low extractability by water and soapy water. This plasticizer has been approved for food-contact use. 

Internal plasticizers are synthesized by copolymerization of suitable monomers. Polymeric non-extractable plasticizers, mostly copolymers having substantially lower glass transition temperatures due to the presence of plasticizing ( soft ) segments such as poly(ethylene-co-vinyl acetate) with approximately 45 % vinylacetate content, ethylene-vinyl acetate-carbon monooxide terpolymer, or chlorinated PE, are available for rather special applications in medicinal articles (Meier, 1990). In this case, the performance of the internally plasticized polymers is the principal advantage. However, copolymerization may account for worse mechanical properties. A combination with external plasticizers may provide an optimal balance of properties. For example, food contact products made from poly(vinylidene chloride) should have at most a citrate or sebacate ester based plasticizers content of 5 % and at most 10 % polymeric plasticizers. 

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