Chemistry Reference
In-Depth Information
er bifunctional sulfur-involving compounds, and also of their mixes with
different bisphenols in environment of polar organic solvents. As in case
of polyesterketones, the synthesis of their thioanalogs is recommended
to be carried to out in inert medium at temperatures below 400 °C in the
presence of catalyst (hydroxides, carbonates and hydrocarbonates of alkali
metals).
The aromatic polyesterketones can also be produced by polyconden-
sation or homopolycondensation of compounds like halogen-containing
arylketone phenols and arylenedihalogenides of different functionality at
elevated temperature and when the salts of alkali and alkali-earth metals in
environments of high-boiling polar organic solvents are used as catalysts
[222, 304-312]. The 4-halogen-3-phenyl-4-hydroxybenzophenone, 4-(
n
-
haloidbenzoyl)-2,6-dinethylphenol and others belong to monomers with
mixed functional groups.
The polycondensation process when synthesizing polyesterketones
and polyesteresterketones can be performed in the melt [223, 313-317]
too. So, it is possible to produce the aromatic polyesterketones by means
of interaction in melt of 4,4′-difluorobenzophenone with trimethylsilox-
ane esters of bisphenols with different bridged groups in the presence of
catalyst (cesium fluoride - 0.1% from total weight of both monomers) at
220-270 °C [318]. The monomers do not enter the reaction without cata-
lyst at temperatures below 350 °C. The reduced viscosity of 2% solution
of polymer in tetrachloroethane at 30 °C is 0.13-1.13 dL/g, the molecular
weight - 3200-60,000, glassing temperature is 151-186 °C, melting point
is 240-420 °C. According to the data of thermogravimetric analysis in the
air the mass loss of polymer is less than 10%, when temperature elevates
from 422 °C to 544 °C with the rate 8°/min.
To increase the basic physical-mechanical characteristics and repro-
cessibility (the solubility, in particular), the polyesterketones and polyes-
teresterketones are synthesized [319-329] through the stage of formation
of oligomers with end functional groups accompanied with the consequent
production of block-copolyesterketones or by means of one-go-copoly-
condensation of initial monomers with production of copolyesterketones.
The polyesteresterketones, their copolymers and mixes are used for
casting of thermally loaded parts of moving transport, instrument, ma-
chines, and planes. They are used in articles of space equipment: for
cable insulation, facings (pouring) elements. For instance, the illumina-
tors frames of planes and rings for high-frequency cable are made of
