Polyvinylidene chloride
From Plastics Wiki, free encyclopedia
Polyvinylidene chloride (or polyvinylidene dichloride, abbreviated as PVDC) is a polymer derived from the monomer vinylidene chloride (or vinylidene dichloride).
Ralph Wiley, a Dow Chemical lab worker, accidentally discovered polyvinylidene chloride in 1933. While cleaning laboratory glassware, Wiley came across a vial he could not scrub clean. Dow researchers made this material into a greasy, dark green film, first called "Eonite" and then Saran.
The military sprayed Saran on fighter planes to guard against salty sea spray and carmakers used it for upholstery. Dow later got rid the of Saran's green color and unpleasant odor.
The most popularly known use of polyvinylidene chloride came in 1953, when Saran Wrap, a plastic food wrap was introduced. In 2004, however, the formula was changed to Low density polyethylene out of environmental concerns about the chloride.
In packaging, polyvinylidene chloride is also applied as a water-based coating to other plastic films such as biaxially-oriented polypropylene (BOPP) and polyester (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.
References
Polyethylenes: Polyethylene (PE), Low density polyethylene (LDPE), High density polyethylene (HDPE), Linear low density polyethylene (LLDPE), Crosslinked polyethylene (XLPE), Ultra High Molecular Weight Polyethylene (UHMWPE)
Other Polyolefins: Polypropylene (PP), Biaxially-oriented polypropylene, Polybutylene (PB), Polyisobutene (PIB)
Polyacrylates: Polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), hydroxyethyl methacrylate (HEMA), Sodium polyacrylate
Polystyrenes: Polystyrene (PS), High impact polystyrene (HIPS), Extruded polystyrene (XPS), Expanded Polystyrene
Polyesters: Polyethylene terephthalate (PET)
Polysulfones: Polysulfone (PSU), Polyarylsulfone (PAS), Polyethersulfone PES, Polyphenylsulfone (PPS)
Polyamides: Polyamide (PA), polyphthalamide (PPA), Bismaleimide (BMI), urea formaldehyde (UF)
Polyurethanes: Polyurethane (PU), Polyisocyanurate (PIR)
Chloropolymers: Polyvinyl chloride (PVC), Polyvinylidene dichloride (PVDC)
(Chloro)fluoropolymers: Fluoropolymer (FE), Polytetrafluoroethylene (PTFE), Polyvinylidene difluoride (PVDF), Polychlorotrifluoroethlyene (PCTFE), Ethylene chlorotrifluoroethlyene (ECTFE)
Other Homopolymers: Polycarbonate (PC), Polylactic acid (PLA), Polyacrylamide (PAM), Polyetheretherketone (PEEK)
Other Copolymers: Acrylonitrile butadiene styrene (ABS), Polybutadiene acrylonitrile (PBAN)
