Polyvinylidene fluoride
[CAS# 24937-79-9]

Identification

• Classification: Catalysts and additives >> Polymer
• Name: Polyvinylidene fluoride
• Synonyms: Poly(vinylidene fluoride); PVDF
• Molecular Formula: (C₂H₂F₂)_n
• Molecular Weight: ~534,000
• CAS Registry Number: 24937-79-9
• EC Number: 607-458-6
• SMILES: FC(F)=C

Properties

• Density: 1.74 g/mL (25 °C)
• Index of Refraction: 1.42

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

Polyvinylidene fluoride (PVDF) is a high-performance thermoplastic polymer known for its excellent chemical resistance, thermal stability, and mechanical properties. It is a type of fluoropolymer, specifically a homopolymer of vinylidene fluoride (VDF), a monomer that is polymerized to form the polymer chain.

PVDF was first synthesized in the 1930s by the chemist Herbert J. Morehouse at the Imperial Chemical Industries (ICI). However, it wasn't until the 1950s that its commercial production and widespread use began. The unique combination of properties exhibited by PVDF, such as its high tensile strength, chemical inertness, and resistance to UV radiation, quickly made it a valuable material for various industrial applications.

One of the most significant features of PVDF is its high chemical resistance. It is resistant to a wide range of chemicals, including acids, bases, solvents, and aggressive liquids. This makes it an ideal material for use in harsh chemical environments, such as in the chemical, pharmaceutical, and food industries. It is used in piping, tanks, valves, and seals for handling corrosive substances. PVDF is also resistant to degradation caused by UV light, making it suitable for outdoor applications.

PVDF also exhibits excellent thermal stability, with a melting temperature typically ranging from 160°C to 170°C. This high melting point makes it useful in applications requiring materials that can withstand high temperatures. Additionally, PVDF has good electrical insulating properties, which have led to its use in the production of cables and wires for the electronics industry.

In addition to its chemical and thermal properties, PVDF has notable mechanical strength. It is a rigid and tough material, which allows it to maintain its structural integrity even under stress. This strength, combined with its resistance to chemical degradation, makes PVDF suitable for a variety of demanding applications in industries such as aerospace, automotive, and energy.

PVDF is commonly used in the manufacture of membranes, particularly for water filtration and separation processes. Its chemical resistance, coupled with its ability to form highly porous structures, makes it an excellent material for filtration membranes, which are used in desalination plants, wastewater treatment, and chemical separation applications.

Another notable application of PVDF is in the production of piezoelectric materials. Due to its ability to generate an electric charge when subjected to mechanical stress, PVDF is used in sensors, actuators, and energy-harvesting devices. It has applications in medical devices, vibration sensors, and pressure sensors.

In addition to its traditional applications, PVDF has found use in the energy sector, particularly in the development of advanced battery technologies. PVDF is used as a binder in lithium-ion batteries, where it plays a crucial role in holding the active materials together and ensuring the proper functioning of the battery.

The production of PVDF involves polymerization processes, with suspension polymerization being the most common method. The polymerization of vinylidene fluoride (VDF) is carefully controlled to produce the desired molecular weight and properties. PVDF can be processed using standard thermoplastic processing techniques such as extrusion, injection molding, and blow molding.

Despite its many advantages, PVDF is not without its challenges. It can be difficult to process due to its high melting point and tendency to degrade at high temperatures. Additionally, its high cost compared to other plastics has limited its use in some applications.

In conclusion, polyvinylidene fluoride (PVDF) is a versatile and durable polymer with a wide range of applications due to its excellent chemical resistance, high thermal stability, mechanical strength, and electrical insulating properties. It is used in industries ranging from chemicals and pharmaceuticals to electronics and energy, and continues to be an important material in advanced technological applications.

References

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