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Pyranine Based Ion‐Paired Complex as a Mechanophore in Polyurethanes
Author(s) -
Aerts Annelore,
Lugger Sean J. D.,
Heuts Johan P. A.,
Sijbesma Rint P.
Publication year - 2021
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.202000476
Subject(s) - dissociation (chemistry) , polymer , pyranine , fluorescence , pyrene , polyurethane , polymer chemistry , materials science , dimethylformamide , solvent , photochemistry , elastomer , tetrahydrofuran , tetraphenylethylene , chemical engineering , chemistry , organic chemistry , aggregation induced emission , composite material , physics , quantum mechanics , engineering
A new mechanophore for polyurethane thermoplastic elastomers based on ion‐paired complexes is developed. 8‐(2‐hydroxyethoxy)pyrene‐1,3,6‐trisulfonate (HEPTS) is incorporated into polyurethanes as an end‐capper and aggregates in apolar media. Aggregation of the ionic HEPTS end groups in solution depends on concentration solvent polarity. The addition of dimethylformamide to a tetrahydrofuran solution of the polymer results in the dissociation of the aggregates and a significant shift in fluorescence emission from yellow to blue. The same shift in fluorescence emission is induced by stretching the solid polymer at strains larger than 1 and stresses above 7.5 MPa, with a clear increase above 12.5 MPa. Strain induced dissociation of HEPTS aggregates not attached to the polymer chain leads to fluorescence changes that are much less reproducible.