Chemistry Reference
In-Depth Information
There is a lot of information available now on the structure and proper-
ties of polyesteresterketones [216, 217].
The polyesteresterketone is specially designed material meeting the
stringent requirements from the point of view of heat resistance, inflam-
mability, products combustions and chemical resistance [218, 219]. “Vic-
trex
R
” owns the unique combination of properties: thermal characteristics
and combustion parameters quite unusual for thermoplastic materials,
high stability to effect of different dissolvents and other fluids [220, 221].
The polyesteresterketone can be of two types: simple (unarmored) and
reinforced (armored) by glass. Usually both types are opaque though they
can become transparent after treatment at certain conditions. This happens
due to the reversible change of material's crystallinity which can be recov-
ered by tempering. The limited number of tinges of polyesteresterketones
has been produced for those areas of industry where color articles are used.
The structure crystallinity endows polyesteresterketones by such ad-
vantages as:
• stability to organic solvents;
• stability to dynamical fatigue;
• improved thermal stability when armoring with glass;
• ability to form plasticity at short-term thermal aging;
• orientation results in high strength fibers.
“Victrex
R
” loses its properties as elasticity and solidity moduli with
increasing temperature, but the range of working temperatures of polyes-
teresterketones is wider in short-term process (like purification) than that
of other thermoplastic materials. It can be exploited at 300 C or higher.
The presumable stint at 250 °C is more than 50,000 hours for the given
polyesteresterketone. If one compares the mechanical properties of poly-
esteresterketone, polyestersulfone, nylon and polypropylene then he finds
that the first is the most resistant to wear and to dynamic fatigue. The
change of mechanical characteristics was studied in dependence of sorp-
tion of СН
2
ССl
2
.
Polyesteresterketones, similar to any other thermoplastics, is isolation
material. It is hard-burnt and forms few smoke and toxic odds in combus-
tion, the demand in such materials arises with all big hardening require-
ments to accident prevention.
If one compares the smoke-formation in combustion of 2-3 mm of
samples from ABC-plastics, polyvinylchloride, polystyrene, polycarbon-
ate, polytetrafluorethylene, phenolformaldehyde resin, polyestersulfone,
