Synthesis via ATRP and Anchoring Properties of Ammonium-Terminated Monofunctional or Telechelic Polystyrenes

Mono- and di-(trimethylammonium)-terminated polystyrenes with similar molar masses were synthesized. Bromopolystyrenes were first prepared by atom transfer radical polymerization (ATRP) using (N-Boc-propylamino)-2-bromoisobutyrate as initiator and Cu(I)Br/2,2'-bipyridine as catalytic system in bulk at 110 °C. α,ω-Telechelic polymer with double molecular weight with respect to the starting polystyrene was then obtained under atom transfer radical coupling process using 2,2/-bipyridine and copper(0) mediated reductive conditions in anisole. Final (trimethylammonium)-terminated polystyrenes were eventually obtained after removal of the tert-butyloxycarbonyl group and permethylation reactions. Intermediate and final polymers were characterized by 1 H NMR. The aligning properties of the obtained polymers for liquid crystals have been investigated. Pretilt and zenithal anchorings on ITO/glass substrates were measured. Finally, the possibility for the telechelic polystyrene to form a network in an inverted microemulsion was also considered.