|

800-752-7770
Tel: 704-739-7463
Fax: 704-739-5566

|
|
|
Overview of Fluoropolymers
|
|
The chemical structure of
fluoropolymers (also called
fluoroplastics) primarily
consists of carbon and fluorine.
The particular combination of
these two chemical elements
arranged along the molecular
chain imparts a unique set of
properties to these types of
carbon-fluorine based polymers.
View an in-depth table of
fluoropolymer properties
Commercially available
fluoropolymers include:
PTFE (Poly tetra-fluoro
ethylene) - A fully
fluorinated polymer available in
various unmodified and modified
grades
FEP (Fluorinated ethylene
propylene) - A fully
fluorinated copolymer
PFA, MFA (Perfluoroalkoxy)
- A fully fluorinated copolymers
ETFE (Ethylene tetra-fluoro
ethylene) - A partially
fluorinated polymer containing
hydrogen
ECTFE (Ethylene chloro tri-fluoro
ethylene) - A copolymer of
ethylene and
chlorotrifluoroethylene
PCTFE (Poly chloro tri-fluoro
ethylene) - A copolymer
containing chlorine
PVDF (Poly vinyledene
fluoride) - A partially
fluorinated polymer containing
carbon-to-carbon double bond
These materials are also
known by their trade names:
PTFE, FEP, PFA - Teflon,®
Neoflon®, Hyflon®
MFA - Hyflon®
ETFE - Tefzel®, Neoflon®
ECTFE - Halar®
PCTFE (or CTFE) - Neoflon®
(originally Kel-F®)
PVDF - Solef®, Hylar®,
Kynar®
Teflon®, Tefzel® are the
trademarks of E.I. DuPont de
Nemours Company
Neoflon®, Polyfon® are the
trademarks of Daikin America
Inc.
Hyflon®, Halar®, Hylar® are the
trademarks of Solvay Solexis,
Inc.
Kynar® is the trademark of Elf
Atochem North America, Inc.
Kel-F® was the trademark of 3M
Company ( this trade name is now
discontinued)
|
|
|
Comparison of Material
Properties
|
|
In general, the chemical
resistance of fluoropolymers is
superior to most other families
of plastics.
One of the most unique features
is their chemical inertness,
which varies between the
different fluoropolymers. The
fully fluorinated resins such as
PTFE, FEP, PFA and MFA exhibit
chemical inertness to a wider
range of chemicals than do the
partially fluorinated polymers
(CTFE, ECTFE).
Usually, however, a better
property in one or two areas is
accompanied by a diminished
property in others. For example,
PTFE is better than PVDF in
chemical resistance but it has
lower mechanical properties at
normal ambient temperatures.
On the other hand, the flex
modulus of PVDF is considerably
higher than PTFE, FEP, PFA or
MFA. This makes tubing of PVDF
considerably more rigid than the
other materials; however it has
higher tensile strength at
ambient temperatures.
Fully fluorinated polymers (Perfluoropolymers)
such as PTFE, FEP and PFA offer
better thermal (higher use
temperature) and chemical
resistance properties than their
partially fluorinated
counterparts like ECTFE or
PCTFE, but trade off mechanical
properties (toughness, abrasion,
cut through resistance) that
ECTFE and PVTFE possess.
All of these fluoropolymers are
generally acceptable for a wide
variety of industrial and
commercial applications.
|
|
|
Effects of Fabrication Upon
Properties
|
|
In general, it is safer to
assume that fabrication
procedures affect some
properties of PTFE, FEP and PFA
products. Certain physical
properties such as tensile
strength, permeability and
dielectric strength vary with
fabrication conditions. Examples
of causes of these may be
macroscopic flaws, microporosity
(for PTFE) and crystallinity.
The extent of the variation
depends upon the specific
conditions of fabrication.
Properties of PTFE, FEP and PFA
that remain relatively
unaffected are as follows:
1. Chemical resistance
2. Long-term weathering
3. Non-stick
4. Non-flammability
5. Low dielectric constant and low dissipation factor
6. High arc resistance, surface and volume resistivities
7. Flexibility at low temperatures
8. Thermal stability at high temperatures
9. Low coefficient of friction
|
|