Polystyrene
In 1831, styrene
monomer was prepared by M Bonastre by distilling
storax balsam.
E Simon observed that it solidified in storage
although he wrongly assumed that an oxide had
been formed. AW Hofmann and J Blyth in 1845
obtained the solid by heating styrene in the
absence of oxygen, found that it had the same
composition as styrene and called it metastyrene.
In 1902 and again in 1911, A
Kronstein and FE Matthews respectively, attempted
to produce the polymer but neither were
successful because of premature solidification of
the monomer. C Dufraisse and C Moureu found, in
1922, that the monomer could be stabilised by the
addition of small amounts of aromatic amines and
phenols.
Styrene was used by I Ostromislenskii for
studying the mechanism of polymerisation in the
period 1922 to 1925 as did H Staudinger in the
period around 1930.
In the 1930s, IG Farben in Germany and Dow
Chemicals in the USA started commercial producton
of styrene based on a synthesis from benzene and
ethylene first devised by M Berthelot in 1851.
Large scale production of
styrene was undertaken during World War II,
especially for the production of synthetic
rubbers based on styrene/butadiene copolymers.
The availability of low cost styrene monomer
after the war led to rapid growth in the use of
polystyrene. The colour range is unlimited as
polystyrene itself is colourless and transparent.
It is, however a brittle material and to overcome
this problem it was modified by blending with a
rubber, though this sacrificed clarity. Even
tougher materials based on copolymers of styrene with
acrylonitrile and butadiene (ABS) were introduced in the 1950s.
Styrene based plastics are
widely used for toys, housings for electrical
appliances, etc. and in packaging which also
makes extensive use of foamed polystyrene.
The use of the Enthone electroless process for
plating on ABS plastics
by Marbon in the USA in 1963 further extended the
usefulness of styrene based polymers.
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