Vinylidene Chloride Polymers

Abstract

Vinylidene chloride is a versatile monomer used primarily for making vinylidene chloride copolymers. These copolymers are mostly used in food packaging to provide a good barrier to mass transport. Most applications rely on the low permeation of oxygen, carbon dioxide, and water vapor. However, the polymers have also been shown to have good barrier to flavors and aromas. Thus, a barrier layer of one of these copolymers in a package structure not only prevents spoilage of the food item but prevents flavor “scalping” on the supermarket shelf. These copolymers are available in three forms. First, resin for extrusion into film or sheet represents the largest segment. This includes monolayer and coextruded film and coextruded sheet. Second, a number of emulsion resins are used for solution applications. A thin layer is coated onto a substrate. Third, copolymer latexes are used for paper coatings, etc. The coatings from solution or latex dry clear. Vinylidene chloride homopolymer does not have commercial application because its melting temperature is too high to permit extrusion without degradation, and it does not dissolve in a suitable solvent for coating.

Radiation-Induced Polymerization of Vinylidene Chloride in Bulk and Included in Thiourea Crystals

“…203 • C in agreement with literature data (1) and with "regular" PVDC. Instead, the PVDC sample prepared by inclusion polymerization shows an endothermal melting point at 184 • C inside the melting interval reported by Brown and White (1). The DTA technique does not permit a quantitative measurement of the melting enthalpy, but a qualitative estimation can be inferred from Figure 7.…”

“…As shown in Scheme 1, PVDC has a regular structure and a high crystallinity (1). As a consequence of the head-totail connection of the monomeric units, the chlorine atoms are arranged in geminal position along the polymer backbone and are lying on the same plane.…”

“…Vinylidene chloride (VDC) or 1,1-dichloroethylene can be easily polymerized by free radical and ionic reactions (1). The resulting polymer, poly(vinylidenechloride) (PVDC) is known for a long time and finds applications in packaging, molding, extrusion and lacquer resins (1).…”

“…The resulting polymer, poly(vinylidenechloride) (PVDC) is known for a long time and finds applications in packaging, molding, extrusion and lacquer resins (1). Several copolymers of VDC are commercially important (1). VDC can also be polymerized with high energy radiation (2)(3)(4).…”

Preparation and characterization of vinylidene chloride‐co‐vinyl chloride copolymer/fluorinated synthetic mica nanocomposites I thermal and mechanical properties studies

“…The copolymers currently used in the commercial process, such as poly vinylidene chloride‐ co ‐vinyl chloride (VDC‐VC copolymer), poly vinylidene chloride‐ co ‐methyl acrylate (VDC‐MA copolymer), and poly vinylidene chloride‐ co ‐acrylonitrile) (VDC‐AN copolymer), are less crystalline, more soluble, and have lower melting temperature and are easier to process than homo‐PVDC. Their most important applications are as packing film to limit oxygen/water vapor transport 1–4. However, new VDC copolymers with good gas barrier properties while maintaining other unique characteristics are still needed.…”