Wolfgang Schöfberger,
"Photoinduced Changes of the Refractive Index in Substituted Fluorenyl-p-phenylene Copolymers"
, in Macromolecular Chemistry and Physics, Vol. 204, Seite(n) 779-786, 2003, ISSN: 1022-1352
Original Titel:
Photoinduced Changes of the Refractive Index in Substituted Fluorenyl-p-phenylene Copolymers
Sprache des Titels:
Englisch
Original Kurzfassung:
A series of substituted 9,90-dihexylfluorenylene-
p-phenylene copolymers (DFPP) were synthesised via a
Suzuki coupling reaction. The copolymers were chemically
modified to introduce photoreactive functionalities. Thiocyanate
groups (SCN) were attached onto a side chain of the
DFPP copolymers. After exposure to UV light the SCN
groups underwent photoisomerisation to the corresponding
isothiocyanate groups (NCS). A significant change of the
refractive index was observed after UV illumination. After
this process the polymer was further modified by a gas phase
reaction with propylamine to transform the photo-generated
NCS groups to derivatives of thiourea. An additional variation
of the refractive index, as well as an increase of the film
thickness h(Dhþ15%), was observed after this reaction. All
polymerisation products were characterised by means of gel
permeation chromatography, thermoanalysis as well asNMR
and IR spectroscopy. The polymers are thermally stable with
decomposition temperatures of around 260 8C and glass transition temperatures in the range of 150–155 8C. The
polymers display blue photoluminescence, which remains
unchanged after UV modification and reaction with propylamine.
A convenient way to produce index and relief
patterns in films of conjugated polymers is demonstrated.