Poly(p-phenylenes) with well-defined side chain polymers

1,4-Dibromo-2,5-bis(bromomethyl)benzene and benzene-2,5-dibromomethyl-1,4-bis(boronic acid propanediol diester) were used as bifunctional initiators in Atom Transfer Radical Polymerization (ATRP) of styrene or in cationic ring opening polymerization (CROP) of tetrahydrofuran in conjunction with CuBr/2,2′-bipyridine or AgSbF₆, respectively. The resulting well-defined macromonomers with low polydispersities, bearing functional groups as bromine or boronic ester were used in Suzuki or Yamamoto type couplings, leading to poly(p-phenylene)s (PPPs) with polystyrene (PSt), polytetrahydrofuran (PTHF) or alternating PSt/PTHF side chains. The new polymers were characterized by GPC, ¹H-NMR, ¹³C-NMR, IR and UV analysis. Thermal behavior of the precursors PSt or PTHF macromonomers and the final polyphenylenes were investigated by TGA and DSC analyses and compared.