10.1021/ma900486m.s001
Kenji Sugiyama
Kenji
Sugiyama
Akira Hirao
Akira
Hirao
Jung-Ching Hsu
Jung-Ching
Hsu
Yi-Chih Tung
Yi-Chih
Tung
Wen-Chang Chen
Wen-Chang
Chen
Living Anionic Polymerization of Styrene Derivatives <i>para</i>-Substituted with π-Conjugated Oligo(fluorene) Moieties
American Chemical Society
2009
block copolymerization results
monomer
fluorene chain length
Living Anionic Polymerization
THF
glass transition temperatures
styrene
manner
luminescence spectra
AB
BA diblock copolymers
2009-06-23 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Living_Anionic_Polymerization_of_Styrene_Derivatives_i_para_i_Substituted_with_Conjugated_Oligo_fluorene_Moieties/2848354
The anionic polymerization of styrene monomers <i>para</i>-substituted with π-conjugated mono-, di-, and tri(9,9-dihexylfluorene) moieties, <b>St-Fl</b>, <b>St-Fl</b><sub><b>2</b></sub>, and <b>St-Fl</b><sub><b>3</b></sub>, was examined under the conditions either in THF at −78 °C or in <i>tert</i>-butylbenzene at 20 °C with <i>sec</i>-BuLi as an initiator. The polymerization of both <b>St-F</b><sub><b>l</b></sub> and <b>St-Fl</b><sub><b>2</b></sub> was found to proceed in a living manner to quantitatively afford the corresponding polymers with predictable molecular weights and narrow molecular weight distributions (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.08). The anionic polymerization of <b>St-Fl</b><sub><b>3</b></sub> was also indicative to proceed in a living manner but with an unpredictable molecular weight. Both AB and BA diblock copolymers with the well-defined and expected structures could be successfully prepared by the sequential addition of <b>St-Fl</b> or <b>St-Fl</b><sub><b>2</b></sub> followed by styrene and <i>vice versa</i>. The block copolymerization results clearly indicate the living nature of the anionic polymerization of <b>St-Fl</b> and <b>St-Fl</b><sub><b>2</b></sub> and the almost same anionic polymerization behaviors of both monomers as styrene in reactivities of monomer(s) and propagating chain-end anion(s). Solubilities, intrinsic viscosities, and glass transition temperatures of the poly(<b>St-Fl</b>) and poly(<b>St-Fl</b><sub><b>2</b></sub>) herein prepared were measured. The optical absorption and luminescence spectra of the studied polymer films showed well-resolved vibronic structures and the peak maxima was progressively increased as the fluorene chain length increased. The luminescence spectra also showed reduced aggregation/excimer emission in comparison with that of parent polyfluorene. The present study suggests that living anionic polymerization could be employed to polymerize other styrene derivatives with π-conjugated moieties in a controlled manner and such polymers may exhibit precisely defined physical properties.