Vinyl vinylidene chloride copolymer

Ninety-six percent of the EDC produced in the United States is converted to vinyl chloride for the production of poly(vinyl chloride) (PVC) (1) (see Vinyl polymers). Chloroform and carbon tetrachloride are used as chemical intermediates in the manufacture of chlorofluorocarbons (CECs). Methjiene chloride, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene have wide and varied use as solvents. Methyl chloride is used almost exclusively for the manufacture of silicone. Vinylidene chloride is chiefly used to produce poly (vinylidene chloride) copolymers used in household food wraps (see Vinylidene chloride and poly(vinylidene chloride). Chloroben2enes are important chemical intermediates with end use appHcations including disinfectants, thermoplastics, and room deodorants. 

Table 7. Absorption Maxima of the Colored Form of Spiroindolinobenzothiopyran 44 in Vinyl Chloride-Vinylidene Chloride Copolymer...

First, the recording layer which contains photochromic spirobenzothiopyran in liquid-crystal polymer or polymer such as vinyl chloride-vinylidene chloride copolymer, is made colored by UV irradiation. In the recording (writing) process, a colorless recording dot in the recording layer is formed by semiconductor laser beams (789 nm, 15-20 mW).100 This process is essentially thermal decoloration of the photomerocyanine form by laser beam. 

Conversely, cling film (plasticised PVC/PVDC, (poly(vinyl chloride)/poly (vinylidene chloride), copolymer, which has very high gas-barrier properties) on peeling from a roll generates static electricity thus promoting adhesion to a surface, e.g., ceramics, but not metallic surfaces which conduct the static electricity away... 

Vinylidene chloride copolymers are available as resins for extrusion, lalices for coating, and resins for solvent coating. Comonomer levels range from 5 to 20 wt %. Common comonomers are vinyl chloride, acrylonitrile, and alkyl acrylates. The permeability of the polymer is a function of type and amount of comonomer, As the comonomer fraction of these semicrystalhne copolymers is increased, the melting temperature decreases and the permeability increases The permeability of vinylidene chloride homopolymer has not been measured. 

Values for vinylidene chloride copolymer and ethylene-vinyl alcohol are extrapolated fromhighertemperatures. ... 

Many synthetic laiices exist. They contain butadiene and. styrene copolymers telasioiiieric). styrene - butadiene copolymers ireximms). butadiene and acrylonitrile, chloroprene copolymers, methacrylate and acrylate ester copolymers, vinyl aeelate copolymers, vinyl and vinylidene chloride copolymers, ethylene copolymers. Huorinated copolymers, acrylamide copolymers, styrene-acrolein copolymers, and pyrrole and pyrrole copolymers. Yluny of these lattee.s also have earboxylated versions. 

Vinylidene chloride-vinyl chloride copolymers were originally developed for thermoplastic molding applications, and small amounts are still used for this purpose. Extrusion of VDC-VC copolymers is the main fabrication technique for filaments, films, rods, and tubing or pipe, and involves the same concerns for thermal degradation, streamlined flow, and noncatalytic materials of construction as described for injection-molding resins. A significant application for vinylidene chloride copolymer resins is in the... 

Plesh (188) treated polyvinyl chloride and vinyl chloride-vinylidene chloride copolymers with aluminium chloride or titanium tetrachloride for initiating the carbonium polymerization of styrene. As expected (218)... 

Molecular Structure of Vinyl Chloride—Vinylidene Chloride Copolymers by Carbon-13 NMR... 

Equations to Calculate Monomer Composition of Vinyl Chloride-Vinylidene Chloride Copolymers from 13C NMR Areas... 

The data shown in Tables HI and TV show that the 13C nmr spectra of vinyl chloride-vinylidene chloride copolymers have a redundancy of structural relationships. By analyzing a range of compositions, this system has been found to yield a reasonable description of both monomer composition and monomer sequence distribution. The data also show that this copolymer is a good example of a system best described by first order Markovian statistics as compared to Bernoullian statistics. 

Typical applications include the bonding of vinyls, of expanded polyurethane, nylon, vinylidene chloride copolymers, and phenolic resin mouldings. 

The principal solution to fabrication difficulties is copolymerization. Three types of comonomers are commercially important vinyl chloride acrylates, including alkyl acrylates and alkylmethacrylates and acrylonitrile. When extrusion is the method of fabrication, other solutions include formulation with plasticizers, stabilizers, and extmsion aids plus applying improved extrusion techniques. The literature on vinylidene chloride copolymers through 1972 has been reviewed (1). 

A primary use of vinylidene chloride copolymer lacquers is the coating of films made from regenerated cellulose or of board or paper coated with polyamide, polyester, polypropylene, poly(vinyl chloride), and polyethylene. The lacquer imparts resistance to fats, oils, oxygen, and water vapor (165). 

Materials are also blended with VDC copolymers to improve toughness (211—214). Vinylidene chloride copolymer blended with ethylene—vinyl acetate copolymers improves toughness and lowers heat-seal temperatures (215,216). Adhesion of a VDC copolymer coating to polyester can be achieved by blending the copolymer with a linear polyester resin (217). 

ATBC is used as a plasticizer for flexible films made of vinylchloride-vinylidene chloride copolymer and cellulose. It is used as a plasticizer in food contact applications and in vinyl toys for children (low toxicity). ATBC provides adherence to metals, low volatility, and resistance to yellowing. Also used in ink formulations, vinyl gloves, a non-VOC solvent in nitrocellulose propellants, a plasticizer in nail polishes, adhesives and coatings, and for coating both paperboard and foil. 

In this paper, the water sorption of two commercially available vinylidene chloride copolymers is studied using IGC at low probe concentrations. The copolymers are a poly (vinylidene chloride-vinyl chloride) copolymer (Saran B) and a poly (vinylidene chloride-acrylonitrile) copolymer (Saran F). These copolymers are extensively used in the form of films, coatings, and film laminates in various industrial applications (for example, packaging of foods and pharmaceuticals) where their diffusion characteristics are of prime importance. 

Polyco [Borden], TM for a series of thermoplastic polymers in the form of water emulsions or solvent solutions, applied to vinyl acetate polymers and copolymers, butadiene-styrene copolymer lat-ics, polystyrenes, vinyl and vinylidene chloride copolymers, acrylic copolymers, and water-soluble polyacrylates. 

Fig. 1. Chemical structures of barrier polymers, (a) Vinylidene chloride copolymers (b) hydrolyzed ethylene—vinyl acetate (EVOH) (c) acrylonitrile barrier polymers (d) nylon-6 (e) nylon-6,6 (f) amorphous nylon (Selar PA 3426), y = x + 2 (g) nylon-MXD6 (h) poly(ethylene terephthalate) and (i) poly(vinyl...

Permeation in the vinylidene chloride copolymer and the polyolefins is not affected by humidity the permeability and diffusion coefficient in the ethylene—vinyl alcohol copolymer can be as much as 1000 times greater with high humidity (14—17). 

Fig. 15. Oxygen permeability versus 1/specific free volume at 25 °C (30). 1. Polybutadiene 2. polyethylene (density 0.922) 3. polycarbonate 4. polystyrene 5. styrene-co acrylonitrile 6. polyethylene terephthalate) 7. acrylonitrile barrier polymer 8. poly(methyl methacrylate) 9. poly(vinyl chloride) 10. acrylonitrile barrier polymer 11. vinylidene chloride copolymer 12. polymethacrylonitrile and 13. polyacrylonitrile. See Table 1 for unit conversions.

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