TY  - JOUR
A1  - Weis, Philipp
A1  - Hess, Andreas
A1  - Kircher, Gunnar
A1  - Huang, Shilin
A1  - Auernhammer, Günter K.
A1  - Koynov, Kaloian
A1  - Butt, Hans-Jürgen
A1  - Wu, Si
T1  - Effects of Spacers on Photoinduced Reversible Solid-to-Liquid Transitions of Azobenzene-Containing Polymers
JF  - Chemistry - a European journal
N2  - Photoisomerization in some azobenzene-containing polymers (azopolymers) results in reversible solid-to-liquid transitions because trans- and cis-azopolymers have different glass transition temperatures. This property enables photoinduced healing and processing of azopolymers with high spatiotemporal resolution. However, a general lack of knowledge about the influence of the polymer structure on photoinduced reversible solid-to-liquid transitions hinders the design of such novel polymers. Herein, the synthesis and photoresponsive behavior of new azopolymers with different lengths of spacers between the polymer backbone and the azobenzene group on the side chain are reported. Azopolymers with no and 20 methylene spacers did not show photoinduced solid-to-liquid transitions. Azopolymers with 6 or 12 methylene spacers showed photoinduced solid-to-liquid transitions. This study demonstrates that spacers are essential for azopolymers with photoinduced reversible solid-to-liquid transitions, and thus, gives an insight into how to design azopolymers for photoinduced healing and processing.
KW  - azobenzenes
KW  - isomerization
KW  - photochemistry
KW  - polymers
KW  - self-healing
Y1  - 2019
U6  - https://doi.org/10.1002/chem.201902273
SN  - 0947-6539
SN  - 1521-3765
VL  - 25
IS  - 46
SP  - 10946
EP  - 10953
PB  - Wiley-VCH
CY  - Weinheim
ER  -