Issue 02/2017

From Science and Research
Thermochromic bio-pigments
Chromogenic materials change colour or transparency
depending on temperature, electrical voltage, pressure
or exposure to light. In thermochromic materials,
a pre-determined temperature change triggers this
change in colour. For example, in the food industry, thermochromic
packaging can reveal whether the refrigeration
chain has been interrupted. The temperature-sensitive additives
used in this application are currently only available
on the market as oil-based pigments.
“In particular bioplastics – which will play a major role
in day-to-day life in the future – lose their biobased status
when commercially available thermochromic dyes are
added. Our department has already demonstrated that the
idea of thermochromic bioplastics can work. This is why we
would like to use renewable raw materials when developing
these materials for various applications,” explains
Department head Christian Rabe. The move to Potsdam-
Golm (Germany) enables the eight-person team to profit
from the 25 years of expertise at the Fraunhofer Institute for
Applied Polymer Research (IAP) in the area of biopolymer
research, and to take advantage of synergies. These relate
to the access to technologies and characterization methods,
as well as a more intensive exchange of knowledge with
members of the Biopolymers research division.
In addition to integrating thermochromic effects into
biopolymers, the department Chromogenic Polymers, at
its new location in the Science Park in Golm, is currently
focusing on the development of particularly stable
electrochromic windows for architectural applications or
boat-building, and irreversible thermochromic packaging
films. MT
www.iap.fraunhofer.de
Christian Rabe’s bio-based thermochromic dyes will enable
purely biobased materials to change color in the future (Photo Till
Budde, Fraunhofer IAP)
bioplastics MAGAZINE [02/17] Vol. 12 47