Novel opportunities to investigate elongational behaviour of polymer melts and bio inks

Schubert DW, Bier A, Schrüfer S (2023)

Publication Language: English

Publication Type: Conference contribution, Conference Contribution

Publication year: 2023

Event location: Kopenhagen DK


The thermal stability of recycled polypropyl-
ene should be increased by using renewa-
ble stabilizers known as antioxidants. These
chemical compounds delay the degradation
and aging of polymers by offering a hydrogen
atom to the radical generated during thermal
decomposition, so that the radical does not
react with the polymer chain [1].
In this work the use of Irganox 1010 (industry
standard), lignin and α-tocopherol (vitamin E)
in polypropylene is investigated [2-4]. To assess
the effectiveness of the stabilizers, the oxidation
induction time (OIT) is determined according
to standard (EN ISO 11357-6) [5]. The oxidation
induction time is the time a polymer can resist
at 200 °C until degradation occurs after the
change from nitrogen to oxygen atmosphere.
The objective is to increase that time to more
than 10 minutes. By adding different amounts
of antioxidant, a critical concentration c* is cal-
culated at which the objective is achieved.
A linear relationship between concentration
and thermal stability is found for all systems,
except for the addition of α-tocopherol. The
highest thermal stability is achieved by α-to-
copherol and α-tocopherol succinate, whose
structures are formed on the basis of BHA
(2, 6-di-tert-butyl-4-methoxyphenol) instead of
BHT (2, 6-di-tert-butyl-4-methylphenol), as it is
the case for the other stabilizers [4]. Compared
to the industry standard (Irganox 1010) the
efficiency of α-tocopherol is ten times higher
in the relevant concentration level, making Vi-
tamin E the most suitable antioxidant found in
this research. The wood component lignin also
shows good stabilization effects, but requires
the tenfold concentration c* than Irganox 1010.
Furthermore, the stabilized samples are ana-
lysed with regard to their rheological proper-
ties. At a temperature of 250 °C, that is equal
to the processing temperature in the industry,
degradation occurs during the measurement,
so the unstabilized sample (pure PP) shows
a lower viscosity compared to the stabilized

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How to cite


Schubert, D.W., Bier, A., & Schrüfer, S. (2023). Novel opportunities to investigate elongational behaviour of polymer melts and bio inks. In Proceedings of the Nordic Polymer Days 2023. Kopenhagen, DK.


Schubert, Dirk W., Alexander Bier, and Stefan Schrüfer. "Novel opportunities to investigate elongational behaviour of polymer melts and bio inks." Proceedings of the Nordic Polymer Days 2023, Kopenhagen 2023.

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