Polyvinyl fluoride

Description

A clear, tough, flexible thermoplastic resin formed from vinyl fluoride. Polyvinylidene fluoride (PVDF) [(CH2 – CF2)n] is a thermoplastic fluorinated polymer that was invented and patented by the DuPont Corporation in 1948. Developed as a coating, its first widespread commercial use was as a pigmented liquid coating called Kynar 500®. Today, PVDF is used as a coating for metals. It is often made into a copolymer with other fluorinated monomers in order to improve or modify its properties. This is an unusual polymer, i.ee, very specialized and expensive.

Synonyms and Related Terms

Polyvinylidene difluoride (PVDF); poly(vinylene fluoride); poli(fluoruro de vinilo) (Esp.); fluorure de polyvinyl (Fr.); polivinil fluoruro (It.); fluoreto de polivinilo (Port.); poly(vinyl fluoride); polyvinylfluoride (PVF), poly(1,1-difluoroethane)

Examples: Tedlar® [DuPont]; Kynar 500 (Arkema); Hylar 5000 (Solvay Solexis) ; Solef (Solvay); Sygef

Applications

• Protective coatings, especially in stressful environments (high temperature, sun, acid, etc)
• Acid resistant filters
• Surgical sutures, medical devices
• Electrical braids

Personal Risks

• Considered safe for normal use at room temperature
• Fluoropolymers will degrade upon prolonged heating or in a fire, liberating Hydrogen Fluoride (HF) and Carbonyl Fluoride (COF2). HF is toxic to skin and can damage bones if allowed to seep into the skin. COF2 is toxic if inhaled or it comes into contact with moist skin.

Collections Risks

Degrades with heat and light to produce hydrofluoric acid.

Environmental Risks

Hazardous to environment if catches fire (requires extreme temperatures to do so).

Physical and Chemical Properties

• Soluble in cyclohexanone, dimethyl formamide
• Affected by strong alkalis, ester and ketones.
• Insoluble in water, oils, alcohols, acids, bleaches, weak alkalis
• Inert in most aliphatic, aromatic and chlorinated compounds.
• Tenacity = 2.2-4.4 g/denier
• Elongation = 15-30%
• Moisture regain = 0.04%
• Melting Point = 170
• Density = 1.3-1.7
• Refractive Index = 1.42

Resources and Citations

• Contributions: Catherine Stephens: AIC Plastics Panel, 2020.

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002

• J.Gordon Cook, Handbook of Textile Fibres:II Man-made Fibres, Merrow Publishing Co. , Durham, England 1984, p.520.