Hyperbranched pyridylphenylene polymers based on the first-generation dendrimer as a multifunctional monomer†
Abstract
An A6 + B2 approach was applied for the first time to synthesize novel hyperbranched pyridylphenylene polymers by Diels–Alder cyclocondensation reaction. For this, the first-generation pyridylphenylene dendrimer with six ethynyl functionalities (A6) was used as a branching core for the molecule growth. The phenyl-substituted bis(cyclopentadienone)s (B2) of different structures were used as co-monomer in the reaction. A careful choice of reaction conditions allowed us to obtain high molecular weight polymers without undesirable gelation. The molecular weight of the polymers varied in the range of 10 800–80 100 with a polydispersity degree of 1.69 to 4.07 according to SEC analysis. The 1H and inverse-gated decoupling 13C NMR combined with heteronuclear single quantum correlation and heteronuclear multiple bond correlation measurements were used to estimate the branching degree of the polymers synthesized.