Polyvinylidene chloride
Names | |
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IUPAC name
Poly(1,1-dichloroethene)[1]
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Other names
Poly(vinylidene dichloride)
Polydene | |
Identifiers | |
Abbreviations | PVDC |
ChemSpider |
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ECHA InfoCard
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100.125.127 |
CompTox Dashboard (EPA)
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Properties | |
(C2H2Cl2)n | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Polyvinylidene chloride, or polyvinylidene dichloride (PVDC), is a
History
Ralph Wiley accidentally discovered polyvinylidene chloride polymer in 1933.
Ralph Wiley went on to become one of Dow Chemical's research scientists and invent and develop many plastics, chemicals and production machines.
The military sprayed Saran on fighter planes to guard against salty sea spray, and carmakers used it for upholstery. Dow later devised a formulation of polyvinylidene chloride free of unpleasant odour and green colour.
The most well known use of polyvinylidene chloride came in 1953, when
Properties
It is a remarkable barrier against water, oxygen, and aromas. It has a superior chemical resistance to
Above 125 °C, it decomposes to produce
Disadvantages
While extremely useful as a food packaging agent, the major disadvantage of polyvinylidene chloride is that it will undergo thermally induced dehydrochlorination at temperatures very near to processing temperatures. This degradation easily propagates, leaving polyene sequences long enough to absorb visible light and change the color of the material from colorless to an undesirable transparent brown (unacceptable for one of polyvinylidene chloride's chief applications: food packaging). Therefore, there is a significant amount of product loss in the manufacturing process, which increases production and consumer costs.
Fiber types
Saran fiber is produced in monofilament, multifilament-twist, and
Uses
Packaging
Polyvinylidene chloride is applied as a water-based coating to films made of other plastics, such as biaxially-oriented polypropylene (BOPP) and polyethylene terephthalate (PET). This coating increases the barrier properties of the film, reducing the permeability of the film to oxygen and flavours and thus extending the shelf life of the food inside the package. It can also impart a high-gloss finish, which may be aesthetically pleasing and also provides a high degree of scuff resistance if applied over print.
Other
In household settings, PVDC is used in cleaning cloths, filters, screens, tape, shower curtains, and garden furniture. Industrially, it is used in screens, artificial turf, waste-water treatment materials, and underground materials. PVDC is also used in doll hair, stuffed animals, fabrics, fishnet, pyrotechnics, and shoe insoles. It was used in special photographic film.
Trademarks (producers)
- Saran TC and Saran LS (Asahi-Kasei)
- (formerly) Saran Wrap and Saranex (Dow Chemical)
- Ixan and Diofan (SolVin)
- SK Saran
See also
References
- ^ "Vinylidene Chloride". pubchem.ncbi.nlm.nih.gov. Retrieved 28 August 2019.
- ISBN 978-0-313-34743-6. Retrieved 12 July 2012.
- ^ ISBN 978-0-313-31345-5. Retrieved 12 July 2012.
- ISBN 978-0-19-530796-2. Retrieved 12 July 2012.
- ^ Mary Bellis. "Saran Wrap ®". inventors.about.com. Archived from the original on May 24, 2012. Retrieved July 12, 2012.
- ISBN 978-3-527-62143-9. Retrieved 12 July 2012.
- B.A. Howell, J. Polym. Sci., Polym. Chem. (ed) 1987, 25, 1681–1695.
- B.A. Howell, B.S. Warner, C.V. Rajaram, S.I. Ahemed and Z. Ahmed, Polym. Adv. Technol., 1994, 5, 485.
- B.A. Howell and S. M. Jane, “Impact of Moisture on the Thermal Stability of Vinylidene Chloride Copolymers”, Proceedings, 34th Annual Meeting of the North American Thermal Analysis Society, 2006.
- R.A. Wessling, D.S. Gibbs P.T. Delassus, B.E. Obi, B.A. Howell, Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley and Sons, New York, 4th Edition, 1997, Vol 24, pp. 883–923.