[ Features ]
Polytetrafluoroethylene(PTFE)is in great demand, making it representative
of fluorocarbon polymers. The chemical structure of PTFE has the
hydrogen atoms of polyethylene completely displaced by fluorine
atoms to form a high molecule. It¡¯s chemical structure is
as follow
The shield of fluorine atoms renders the C-C chain immunity to chemical
attack, and the extremely stable C-F bond is attacked only by highly
aggressive agents, such as alkali metals or elemental fluorine
The extremely good electrical properties of PTFE arise from the
rigid ultimately arranged CF2groups coupled with minimum electron
mobility within the molecule.
The height degree of crystalline in PTFE results from the unbranched
structure of the molecules
PTFE exhibits marked anti-adhesive properties and has a low coefficient
of friction. since outwards directed residua valiancy activity is
obstructed by the fluorine Layers.
PTFE has a unique combination of outstanding properties, including
high and low temperature resistance, chemical inertness dielectric
behavior,¡¡non-sticking and self-lubricating properties, and
the lowest coefficient of friction of all solid materials. However,
the mechanical properties of PTFE are not necessarily superior to
those of other plastics. In particular, it suffers from its low
resistance to wear and creep, and low hardness.
The greatest improvements realized by fillers to PTFE are in its
mechanical properties. Most other properties and characteristics
of the basic PTFE are remained. Practically any material that can
withstand the sintering temperature of PTFE(360 380 )can
be used as a filler. Among the filler materials used are glass fiber,
graphite, molybdenum disulfide metal, mullein oxides, carbon fiber,
polyamide, etc.
|