Chemistry Reference
In-Depth Information
should be dried out for approximately 1.8 ´ 10
4
sec at 120 °C until the
moisture is more than 0.05%. The quality of articles based on polysul-
fone worsens at higher moists though the polymer itself does not change
its properties. The polysulfones are reprocessible at temperatures 315-
370 °C.
The high thermal stability of aromatic polysulfones allows one to con-
duct multitime reprocessing without the destruction of polymer and loss
of properties. The pressed procurements can be mechanically treated on
common machine tools.
Besides the aromatic polysulfone on the basis of bisphenylpropane, the
other aromatic polysulfones are produced industrially. In particular, the
industrial manufacture of polysulfones has been carried out by company
“Plastik 3 M” (USA) since 1967 (the polymers are produced by reaction
of electrophylic replacements at presence of catalyst). The polysulfone
labeled “Astrel-360” contains links of following constitution:
The larger amount of first-type links provides for the high glassing
temperature (285 °C) of the polymer. The presence of second-type links
allows one to reprocess this thermoplast with help of pressing, extrusion
and die casting on special equipment [152].
The company “ICI” (Great Britain) produced polysulfones identical
to “Astrel-360” in its chemical structure. However, the polymer “720 P”
of that firm contains greater number of second-type links. Due to this, the
glassing temperature of the polymer is 250 °C and its reprocessing can be
done on standard equipment [153].
Pure aromatic structure of given polymers brings them high thermo-
oxidation stability and deformation resistance. Mechanical properties of
polysulfone allow one to classify them as technical thermoplasts having
high durability, rigidity and impact stability. The polymer “Astrel 360” is
in the same row with carbon steel, polycarbonate and nylon on its durabil-
ity.
