Chemistry Reference
In-Depth Information
polyesteresterketone then it occurs that the least smoke is released by
polyesteresterketone, while the greatest amount of smoke is produced by
ABC-plastic.
“Victrex
R
” exhibits good resistance to water reagents and pH-factor
of different materials starting with 60% sulfuric acid and 50% potassium
hydroxide. The polyesteresterketone dissolves only in proton substances
(such as concentrated sulfuric acid) or at the temperature close to its melt-
ing point. Only α-chlornaphthalene (boiling point 260 °C) and benzophe-
none influence on “Victrex
R
” among organic dissolvents.
The data on the solubility have revealed that two classes of polyester-
esterketones coexist: “amorphous” and crystalline [222].
The division of these polymers into two mentioned classes is justified
only by that the last class, independent of condensation method, crystal-
lizes so fast in conditions of synthesis that the filtering of combustible
solution is not possible. It may be concluded from results obtained that
“amorphous” class of polyesteresterketones is characterized by bisphe-
nols, which have hybridized
sp
3
-atom between phenyl groups.
From the point of view of short-term thermal stability the polyester-
esterketones do not yield most steady materials - polyestersulfones - de-
struction of which is 1% at 430 °C. Yet and still their long-term stability
to UV - light, oxygen and heat must be low due to ketone-group [222].
The influence of environment on polyesteresterketones is not under-
stood in detail, but it has proven that polyesteresterketone fully keeps all
its properties within 1 year. Polyesteresterketones exhibit very good sta-
bility to X-ray, β- and γ- radiations. Wire samples densely covered with
polyesteresterketones bear the radiation 110 Mrad without essential de-
struction.
The destroying tensile stress of polyesteresterketone is almost nil at
exposure to air during 100 hours at 270 °C. At the same time the flex
modulus at glassing temperature of 113 °C falls off precipitously, however
remains sufficiently high compared to that of other thermoplasts.
When placed into hot water (80 °C) for 800 hours the tensile stress and
the permanent strain after rupture of polyesteresterketones decreases neg-
ligibly. The polyesteresterketone overcomes all the other thermoplasts on
stability to steam action. The articles from polyesteresterketone can stand
short exposure to steam at 300 °C.
On fire-resistance this polymer is related to hard-to-burn materials.
