Difference Between PVDF and PTFE

The key difference between PVDF and PTFE is that PVDF has comparatively a low density, whereas PTFE has comparatively a high density.

The term PVDF stands for polyvinylidene fluoride, while the term PTFE stands for polytetrafluoroethylene. Both these are industrially important polymer materials consisting of a large number of monomer units.

CONTENTS

1. Overview and Key Difference
2. What is PVDF 
3. What is PTFE
4. PVDF vs PTFE in Tabular Form
5. Summary – PVDF vs PTFE

What is PVDF?

The term PVDF stands for polyvinylidene fluoride. This material is a highly non-reactive thermoplastic fluoropolymer. We can produce this substance through the polymerization of vinylidene difluoride. PVDF is a specific plastic that is useful in applications where we need high purity and high resistance towards solvents, acids and hydrocarbons.

We can find this material commercially available in different forms of piping products, sheet, tubing, films, plate, and an insulator for premium wire. Moreover, we can use this material for injection, moulding, or welding, and it is a common material in chemical, semiconductor, medical and defence industries and also in lithium-ion batteries. Besides, PVDF is available as a crosslinked close cell foam that is useful increasingly in aviation and aerospace applications.

When considering the most important properties of PVDF, it has a low glass transition temperature and typically about 50-60% crystallinity. It has piezoelectric properties, which come from mechanical stretching and poling under tension processes. There are several forms of PVDF, including alpha, beta, and gamma phases. Moreover, similar to most other fluoropolymer materials, PVDF shows chemical sensitivity to strong bases, caustics, esters, ketones, etc.

What is PTFE?

The term PTFE stands for polytetrafluoroethylene. However, we commonly name this substance Teflon. PTFE has fluorocarbon units as repeating units, and it is a synthetic fluoropolymer. The general formula of this material is (C2F4)n.

PTFE is a polymer having high molecular weight, consisting of only carbon and fluorine atoms. This material exists in the solid state at room temperature. PTFE is hydrophobic; thus, water cannot wet its surface. Moreover, this material is known as a non-reactive and useful material in the non-stick coating. This non-reactive nature of PTFE comes from the strength of the C-F bond. This makes it is useful in manufacturing containers and pipes as well. Further, we can use this material as a lubricant where it can reduce friction and the energy consumption of machinery. Besides, this material is poorly soluble in almost all the solvents.

The method of Teflon production is free-radical polymerization. We can make Teflon by polymerizing tetrafluoroethylene. However, this production process requires a specialized apparatus because tetrafluoroethylene tends to explosively convert into tetrafluoromethane. It is a dangerous side reaction.

When considering the polymer properties, PTFE is a thermoplastic polymer. It occurs as a white solid at room temperature. The density of this material is about 2200 kg/m³. At very low temperatures, Teflon shows very high strength and toughness with self-lubrication properties. At high temperatures, it has good flexibility as well. Since this material is highly unreactive, the chemical species that can make a significant effect on it includes highly reactive chemical species such as alkali metals.

What is the Difference Between PVDF and PTFE?

PVDF and PTFE are short terms for polyvinylidene fluoride and polytetrafluoroethylene, respectively. The key difference between PVDF and PTFE is that PVDF has comparatively a low density, whereas PTFE has comparatively a high density. Moreover, PVDF is produced via polymerization of vinylidene difluoride, while PVDF is produced via free-radical polymerization.

The following infographic lists the differences between PVDF and PTFE in tabular form.

Summary – PVDF vs PTFE

PVDF and PTFE are short terms for polyvinylidene fluoride and polytetrafluoroethylene, respectively. The key difference between PVDF and PTFE is that PVDF has comparatively a low density, whereas PTFE has comparatively a high density.

Reference:

1. “Polyvinylidene Fluoride (PVDF): Complete Guide“. Omnexus

Image Courtesy:

1. “Polyvinylidenfluorid” By NEUROtiker – Own work (Public Domain) via Commons Wikimedia
2. “Polytetrafluoroethylene” By Vectorization: OmenBreeze – Own work based on: Teflon structure.PNG by Dubaj~commonswiki (Public Domain) via Commons Wikimedia