Page 63 - Plastcs News January 2019

teChnoLogy

Scientists develop promising new type of polymers

rganic polymers can nowadays be found in solar well," says Glöcklhofer. "The reaction takes place within
Ocells, sensors, LEDs and in many other technical seconds. The colour changes during the process, so you
applications. One specific type of polymers - known as can see it as it happens."
S-PPVs - were previously regarded as promising in theory Patented technology
but were almost impossible to produce from a technical
perspective. After many years of work, a team has now The new synthesis method has now been patented with the
managed to identify a new chemical synthesis process for help of TU Wien's Research and Transfer Support. Florian
the production of S-PPVs. Glöcklhofer is extremely confident about the commercial
success of the discovery: "It is a simple synthetic method
Sulphur instead of oxygen
for a new, highly promising group of polymers. The
"PPVs are polymers that have superb technological synthesis uses inexpensive base materials and does not
properties," says Florian Glöcklhofer from the Institute of require any palladium catalysts or similar expensive
Applied Synthetic Chemistry at TU Wien. "They conduct interim steps. The method can be scaled up for industrial
electrical current and interact with light in such a way that quantities, is easily reproducible and delivers a product
they are of great interest for use in solar cells or LEDs." that not only boasts improved electronic properties, but
They have a long, solid hydrocarbon structure to which also improved stability," says Glöcklhofer. Additionally,
certain side groups are attached. By choosing different S-PPVs are also relatively non-toxic and biocompatible,
side groups, it is possible to set the electronic properties making them excellent candidates for use in medical
of the material. applications.

Until now, O-PPVs have been used for this; these are PPVs
whose side groups are linked to the rest of the polymer
via an oxygen atom. "If it is possible to replace oxygen
side groups with sulphur side groups, this creates a new
polymer, an S-PPV, which has significantly improved
properties," says Florian Glöcklhofer. "We knew that this
could lead to improvements in the transport of electrical
current and that this would significantly improve overall
stability of the polymer." Experienced colleagues sought
to dissuade Glöcklhofer from attempting to produce these
S-PPVs. "It was believed to be too difficult," explains
Glöcklhofer. Nevertheless, he decided to push ahead with
the project and it soon became apparent that this would
be indeed a complicated challenge. "It was important for
us to develop a synthesising method that was both simple
and low-cost, with as few synthesis steps as possible, and
without the need for expensive special catalysts," stresses
Florian Glöcklhofer. "Ultimately, we want to produce
materials that can be used in industrial applications.
And S-PPV can only be commercially successful if the
production costs do not exceed a certain level."
After four years of hard work, and numerous bitter
setbacks, the team finally succeeded in discovering a
reliable, straightforward method for producing S-PPVs.
Suitable monomers are manufactured with the help of
microwave radiation. These are polymerised and the side
groups can then be further modified. "It works amazingly

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65 Januar y 2019 Plastics News