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PVDF (Polyvinylidene Fluoride): Properties & Applications
PVDF (polyvinylidene fluoride) is a high-performance fluoropolymer that combines broad chemical resistance, strong abrasion resistance, and the highest mechanical strength of the common fluoropolymers. It resists most acids, oxidizers, and halogens but, unlike the fully fluorinated PTFE and PFA, has limited compatibility with strong bases and some polar solvents — which makes it well suited to acidic and oxidizing chemical service below 250°F where a line also needs mechanical strength. As a PVDF material, it serves chemical process lines, ultra-pure water systems, semiconductor fluid handling, and water treatment. Pexco processes PVDF into tubing, rod, pipe, and heat shrink, supplied as both rigid homopolymer (Altaflo® 500) and flexible (Altaflo® 550 PVDF Flex) grades.
This article covers what PVDF is, its key properties, how it compares to other fluoropolymers, the grades and forms Pexco supplies, and where it fits by application.
What is PVDF?
PVDF (polyvinylidene fluoride) is a semi-crystalline fluoropolymer built from the repeating vinylidene fluoride monomer. It sits in the fluoropolymer family alongside PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene), and PFA (perfluoroalkoxy), but it is only partially fluorinated. That structure is the reason for its defining trade-off: PVDF gives up the near-universal chemical inertness and 500°F service of PTFE and PFA in exchange for higher tensile strength, better abrasion resistance, lower cost, and easier processing.
PVDF is most often specified by the Arkema trade name Kynar® (rigid homopolymer) and Kynar Flex® (the more flexible copolymer). Pexco’s Altaflo 500 is produced from 100% virgin-grade Kynar PVDF resin, and Altaflo 550 PVDF Flex from 100% virgin-grade Kynar Flex resin.
PVDF Pror
PVDF’s properties make it the high-strength option among fluoropolymer tubing grades: chemically resistant, abrasion resistant, UL 94 V-0 flame rated (the rigid Altaflo 500 grade also complies with FM4910), and stronger and stiffer than the fully fluorinated grades. The table below lists the measured physical properties of Altaflo 500 PVDF (rigid Kynar homopolymer), the baseline grade.
| Physical Property | ASTM Test | ASTM Test |
|---|---|---|
| Upper service temperature | — | 250°F (121°C) |
| Service temperature range | — | -20°F to 250°F |
| Melting point | D 3418 | ~352°F (178°C) [VERIFY WITH SME — not on the Altaflo sheet; standard Kynar homopolymer value] |
| Density (specific gravity) | D 792 | 1.77–1.79 g/cm³ |
| Tensile strength | D 1708 | 5,000–7,000 psi |
| Elongation | D 638 | 50–200% |
| Flexural modulus | D 790 | 240,000–300,000 psi |
| Hardness | D 2240 | Shore D 76–80 |
| Flammability | UL 94 / FM4910 | V-0; Altaflo 500 also complies with FM4910 (clean-room/semiconductor flammability) |
| Water / regulatory | — | NSF/ANSI 61, NSF/ANSI 372; FDA food-contact (CFR section pending SME — see flag) |
Values are based on tests performed at 73°F and can vary with temperature, chemical concentration, and pressure. Properties shown are for the rigid Altaflo 500 grade; the flexible Altaflo 550 PVDF Flex grade carries a 212°F upper service temperature and higher elongation (200–500%).
One property note matters before the application sections: Altaflo 500 PVDF offers extremely low extractable levels suited to ultra-pure water and high-purity semiconductor service, which is why PVDF appears in both markets despite its lower temperature ceiling.
How Does PVDF Compare to Other Fluoropolymers in Chemical Resistance?
PVDF resists most acids, oxidizers, and halogens (including ozone, chlorine, and bromine), along with aliphatic and aromatic hydrocarbons and alcohols. Where it differs from PTFE, PFA, and FEP is at the extremes: the fully fluorinated grades are near-universally inert, while PVDF has limited compatibility with strong bases (caustics), amines, and polar solvents such as ketones and esters.
In practice, that makes PVDF an excellent choice for acidic and oxidizing chemical service and a poor one for concentrated caustic service. For a specific chemical, check a PVDF chemical compatibility chart rather than assuming inertness — and where the chemistry is aggressive across the full pH and solvent range, step up to PTFE or PFA. PVDF’s advantage over those grades is mechanical: it holds the chemical resistance while adding the tensile and abrasion resistance that pressurized, flowing chemical lines need.
PVDF vs. Other Fluoropolymers: Where It Fits
PVDF is the right fit when an application needs fluoropolymer chemical resistance plus mechanical strength and abrasion resistance, and the operating temperature stays below about 250°F. Where service temperatures climb toward 400–500°F or the chemistry includes strong caustics, PTFE, FEP, or PFA are the better fit. The table compares upper service temperature and tensile strength across Pexco’s Altaflo fluoropolymer grades.
| Material | Grade | Upper Service Temp | Tensile Strength |
|---|---|---|---|
| PTFE (polytetrafluoroethylene) | Altaflo 100 | 500°F (550°F short-term) | 2,500–3,000 psi |
| FEP (fluorinated ethylene propylene) | Altaflo 200 | 400°F | 4,000 psi |
| PFA (perfluoroalkoxy) | Altaflo 400 | 500°F | 4,500 psi |
| PVDF (polyvinylidene fluoride) | Altaflo 500 | 250°F | 5,000–7,000 psi |
| ETFE (ethylene tetrafluoroethylene) | Altaflo 700 | 300°F | 3,100–6,800 psi |
Within the Altaflo line, PVDF trades the temperature ceiling of PTFE and PFA for the highest tensile strength in the group and strong abrasion resistance. That combination of mechanical durability, chemical resistance, and lower material cost than the fully fluorinated grades is why PVDF is widely used in chemical-transfer piping and water treatment, where lines see pressure, flow, and abrasive media but moderate temperatures. For a direct material-by-material breakdown, see the PVDF vs. PTFE comparison guide.
PVDF Grades and Forms
Pexco supplies PVDF in two resin grades and multiple converted forms, so the same chemistry can be matched to a rigid pressure line or a tightly routed flexible run.
Altaflo 500 PVDF (rigid homopolymer). Produced from 100% virgin-grade Kynar® 740 homopolymer resin, Altaflo 500 is the most abrasion- and temperature-resistant PVDF tubing Pexco offers, with a 250°F upper service temperature and 5,000–7,000 psi tensile strength. Its extremely low extractable levels make it well suited to ultra-pure water systems, and it complies with both UL 94 V-0 and FM4910 flammability standards. It is compatible with conventional fittings but is not recommended for flare fittings.
Altaflo 550 PVDF Flex (flexible copolymer). Produced from 100% virgin-grade Kynar Flex resin, Altaflo 550 is a more flexible PVDF with a 212°F upper service temperature, higher elongation, excellent creep resistance, and ozone resistance. It does not support fungal growth, which makes it the preferred grade for ozone-based water disinfection in aquarium, spa, pool, and agricultural systems. It handles less aggressive chemistries and lower temperatures than FEP or PFA at lower cost, while keeping low extractable levels.
Both grades are UL 94 V-0 rated and certified to NSF/ANSI 61 and NSF/ANSI 372, and both are FDA compliant for food-contact use; the rigid Altaflo 500 grade additionally complies with FM4910 for clean-room and semiconductor flammability.
Beyond tubing, Pexco converts PVDF into PVDF rod for machined components, PVDF pipe for chemical-process and water systems, and HSK-600 PVDF heat shrink tubing for high-temperature wire and connection protection.
PVDF Applications
PVDF is specified where chemical resistance has to coexist with mechanical durability at moderate temperatures. Its core applications cluster in four areas:
- Fluid handling and chemical process — chemical-transfer tubing, pipe, and hose where the line sees acids, oxidizers, hydrocarbons, or abrasive media. PVDF’s tensile strength and abrasion resistance make it a durable alternative to PTFE for pressurized chemical service. See fluid handling.
- Ultra-pure and high-purity water — semiconductor wet process, deionized water, and ultra-pure water loops, where PVDF’s low extractable levels protect fluid purity. NSF/ANSI 61 and 372 certification supports potable and lead-free water service.
- Water treatment and disinfection — ozone-based disinfection in municipal, aquarium, pool, spa, and agricultural systems, where the ozone resistance and fungal resistance of Altaflo 550 PVDF Flex are the deciding properties.
- Semiconductor, petrochemical, pulp and paper, and metal finishing — corrosive process environments that need a chemically resistant plastic with structural strength and flame resistance.
How Pexco Processes PVDF
Pexco’s value in PVDF is processing, not resin production: the company converts virgin-grade Kynar and Kynar Flex resin into finished tubing, rod, pipe, and heat shrink to engineered tolerances. Because Pexco runs the extrusion and converting in-house, a PVDF requirement can be matched to the right grade (rigid 500 vs. flexible 550), wall, and dimension for the application rather than forced onto a stock size. Custom sizes are available on request, and extractable data is available for high-purity applications. This processing-and-converting capability, applied across the full Altaflo fluoropolymer line, is what lets Pexco route a single chemical-service or water-system requirement to the correct material and form.
Frequently Asked Questions
What is PVDF material?
PVDF (polyvinylidene fluoride) is a semi-crystalline, partially fluorinated fluoropolymer known for broad chemical resistance, strong abrasion resistance, and high mechanical strength. It is commonly specified by the Arkema trade names Kynar® and Kynar Flex®. PVDF is used for chemical-process tubing and pipe, ultra-pure water systems, and water treatment.
What is the melting point of PVDF?
PVDF has a melting point of approximately 352°F (178°C) for the rigid Kynar® homopolymer; the Kynar Flex® copolymer melts lower. Melting point is not the same as service temperature: PVDF’s continuous upper service temperature is 250°F (Altaflo 500), well below its melt point, because mechanical strength falls off long before the material melts.
What is the temperature range of PVDF?
Rigid PVDF (Altaflo 500) has a service temperature range of -20°F to 250°F. The flexible grade, Altaflo 550 PVDF Flex, is rated to a 212°F upper service temperature. For service above roughly 250°F, PTFE or PFA, rated to 500°F, are the better fluoropolymer choices.
Is Kynar® the same as PVDF?
Yes. Kynar® and Kynar Flex® are Arkema’s trade names for PVDF (polyvinylidene fluoride) resin — Kynar is the rigid homopolymer, Kynar Flex the more flexible copolymer. Pexco’s Altaflo 500 is produced from Kynar homopolymer and Altaflo 550 from Kynar Flex, so “Kynar tubing” and “PVDF tubing” describe the same chemistry. Solef® and Hylar® are other resin trade names for PVDF.
What is the difference between PVDF and PTFE?
PTFE handles higher temperatures (up to 500°F) and resists nearly all chemicals, while PVDF offers far higher tensile strength, better abrasion resistance, and lower cost at moderate temperatures. PVDF is preferred for pressurized, abrasive, or structural chemical-service applications below 250°F; PTFE is preferred for the most aggressive chemistries and highest temperatures. See the PVDF vs. PTFE comparison guide for a full breakdown.
Is PVDF safe for potable water and food contact?
Pexco’s Altaflo 500 and 550 PVDF tubing is certified to NSF/ANSI 61 (drinking water system components) and NSF/ANSI 372 (lead-free compliance), and both grades are FDA compliant for food-contact applications. Confirm the applicable FDA CFR section and documentation for your grade when you request a quote.
Need PVDF tubing, rod, pipe, or heat shrink matched to your chemical service? Contact Pexco engineering or request a quote.