What Is Vinylidene Fluoride?
Vinylidene fluoride is a colorless gas at room temperature and pressure, with the chemical formula CH2=CF2 and an ethereal odor. This compound is explosive; when heated, it burns violently, releasing large amounts of toxic substances.
Polyvinylidene fluoride, created by polymerizing vinylidene fluoride, is a type of fluoropolymer known for its resistance to chemicals and acids, making it suitable for products requiring such resistance. It is classified as a hazardous substance, necessitating specific labeling and notification.
Uses of Vinylidene Fluoride
Vinylidene fluoride serves primarily as a precursor to polyvinylidene fluoride (PVDF). PVDF is a milky white fluorinated resin with superior strength, workability, chemical resistance, high-temperature endurance, and acid resistance compared to other fluoropolymers. Its electrical properties make it ideal for semiconductor manufacturing equipment, food processing machinery, industrial machines, medical devices, and various components such as electrode binders in lithium-ion batteries, membrane materials, seals, and fishing lines.
PVDF membranes are employed in protein and amino acid analysis due to their affinity for amino acids and in sewage treatment and water purification for filtration purposes. Fluorocarbon fishing lines made from PVDF are valued for their durability, transparency, and low visibility underwater.
Molecular Structure of Vinylidene Fluoride
Vinylidene fluoride’s molecular structure features two hydrogen atoms replaced by fluorine atoms. It is a low molecular weight, monomeric compound capable of polymerization into high molecular weight chains. Similar monomers include tetrafluoroethylene (CF2=CF2) and vinyl fluoride (CH2=CHF), leading to polymers like PVDF and polytetrafluoroethylene (PTFE), respectively.
Polyvinyl fluoride (PVF) is another polymer, produced exclusively from vinyl fluoride. Chlorotrifluoroethylene (CF2=CClF) is noted as another related monomer.
Properties of Vinylidene Fluoride
Vinylidene fluoride exhibits high reactivity in polymerization, transforming into PVDF or copolymers when combined with other monomers. Known examples include vinylidene fluoride rubbers (FKM), which are copolymers with hexafluoropropylene and possibly tetrafluoroethylene, offering unique properties.
Other Information on Vinylidene Fluoride
Production Methods of Vinylidene Fluoride
Industrially, vinylidene fluoride is produced by fluorinating 1,1,1-trichloroethane to obtain 1,1-difluoro-1-chloroethane, followed by dehydrochlorination. The demand for fluoropolymers derived from vinylidene fluoride, crucial for semiconductor components and lithium-ion batteries, has recently surged, raising concerns about supply shortages.