polystyrene” [1, p. 170]. Such processes, which could be described as spontaneous
polymerisation, correspond to polymerisation that is triggered actively with human
involvement, e.g. by heating or the exertion of pressure.
What is known as the vulcanisation of rubber is an excellent example of this: in
1839, the American chemist Charles Nelson Goodyear (1800–1860) succeeded in
transforming the rubber that occurs naturally into the polymer product that we now
call rubber by adding sulfur and applying heat. The undesirable tendency of the
rubber to become sticky when heated and crumbly when cooled was overcome as a
result.
Strictly speaking, vulcanisation is a type of polymerisation that is comparable to
what is called addition polymerisation. The definition of this is that two different
raw materials, rather than one and the same raw material, combine in chains to form
macromolecules, as is the case – for example – with polyurethanes (see [1], p. 316).
If there are by-products, water in particular, as is the case with Galalith (from casein
and formaldehyde) or nylon (from hexamethylene diamine and adipic acid), this is
called condensation polymerisation instead (cf. [1], pp. 175, 315–316 and [10],
p. 15) (see Appendix 1).
2.4 About Monomers and Car Tyres
Vulcanisation is not a completely accurate example, because rubber itself is already a
polymer when it combines with sulfur. The British chemist Charles Greville
Williams (1929–1910) was the first to propose this hypothesis. Rubber therefore
has to be considered the product of natural polymerisation that is attributable to basic
components called monomers that have joined together repetitively and continuously, i.e. have combined to form a polymer. The conclusion from this is that it ought
to be possible to create synthetic rubber by polymerising the isolated rubber monomer – the hydrocarbon isoprene. Experiments to do this started at Farbenfabriken
Bayer in 1906 under the direction of Carl Duisburg and Staudinger had already
tackled this research assignment during his time in Karlsruhe (1907–1912) (see [1],
p. 5; [17], p. 67; [18], p. 229). “(At this time, editor’s note) there was great demand
for synthetic rubber due to the rapid growth of the car industry and the rising prices
for plantation rubber on the world market associated with this – particularly in the
German empire, which depended on raw material supplies from the English and
French colonies. This economic situation of his country was another particularly
strong incentive [. . .] for Staudinger to focus on polymerisation reactions like those
occurring with isoprene very early on” [18, p. 230].
In order to make it easier to understand what follows, let us recap here: the term
“monomer” is used for basic molecules that form macromolecules via standard
polymerisation, addition polymerisation or condensation polymerisation. “So macromolecules represent chains of one and the same basic molecule. The number of
the latter in the macromolecule is called its degree of polymerisation” [10, p. 11].
Staudinger also characterised polymerisation as a “peculiar chain reaction” ([1],
92
M. Weber and G. Deussing
polymerisation, correspond to polymerisation that is triggered actively with human
involvement, e.g. by heating or the exertion of pressure.
What is known as the vulcanisation of rubber is an excellent example of this: in
1839, the American chemist Charles Nelson Goodyear (1800–1860) succeeded in
transforming the rubber that occurs naturally into the polymer product that we now
call rubber by adding sulfur and applying heat. The undesirable tendency of the
rubber to become sticky when heated and crumbly when cooled was overcome as a
result.
Strictly speaking, vulcanisation is a type of polymerisation that is comparable to
what is called addition polymerisation. The definition of this is that two different
raw materials, rather than one and the same raw material, combine in chains to form
macromolecules, as is the case – for example – with polyurethanes (see [1], p. 316).
If there are by-products, water in particular, as is the case with Galalith (from casein
and formaldehyde) or nylon (from hexamethylene diamine and adipic acid), this is
called condensation polymerisation instead (cf. [1], pp. 175, 315–316 and [10],
p. 15) (see Appendix 1).
2.4 About Monomers and Car Tyres
Vulcanisation is not a completely accurate example, because rubber itself is already a
polymer when it combines with sulfur. The British chemist Charles Greville
Williams (1929–1910) was the first to propose this hypothesis. Rubber therefore
has to be considered the product of natural polymerisation that is attributable to basic
components called monomers that have joined together repetitively and continuously, i.e. have combined to form a polymer. The conclusion from this is that it ought
to be possible to create synthetic rubber by polymerising the isolated rubber monomer – the hydrocarbon isoprene. Experiments to do this started at Farbenfabriken
Bayer in 1906 under the direction of Carl Duisburg and Staudinger had already
tackled this research assignment during his time in Karlsruhe (1907–1912) (see [1],
p. 5; [17], p. 67; [18], p. 229). “(At this time, editor’s note) there was great demand
for synthetic rubber due to the rapid growth of the car industry and the rising prices
for plantation rubber on the world market associated with this – particularly in the
German empire, which depended on raw material supplies from the English and
French colonies. This economic situation of his country was another particularly
strong incentive [. . .] for Staudinger to focus on polymerisation reactions like those
occurring with isoprene very early on” [18, p. 230].
In order to make it easier to understand what follows, let us recap here: the term
“monomer” is used for basic molecules that form macromolecules via standard
polymerisation, addition polymerisation or condensation polymerisation. “So macromolecules represent chains of one and the same basic molecule. The number of
the latter in the macromolecule is called its degree of polymerisation” [10, p. 11].
Staudinger also characterised polymerisation as a “peculiar chain reaction” ([1],
92
M. Weber and G. Deussing