Synthesis and properties of polyethylene with side‐chain triphenylamines as hole‐transporting materials

Abstract

Abstract The copolymerization of ethylene with triphenylamine (TPA)‐containing α‐olefin monomer 1 using a rac ‐Et(Ind) 2 ZrCl 2 ( EBIZr )/MAO catalytic system was investigated to prepare polyethylene with pendent TPA groups. Despite the presence of a large excess of TPA moieties, the polymerization reactions efficiently produce copolymers of high‐molecular‐weight with the comonomer incorporation up to 6.1 mol % upon varying the comonomer concentration in the feed. Inspection of the aliphatic region of the 13 C‐NMR spectrum and the estimated copolymerization parameters ( r 1 ≈ 0 for 1 and r E ≈ 43 for ethylene) reveal the presence of isolated comonomer units in the polymer chain. While UV–vis absorption measurements of the copolymers show an invariant absorption feature, PL spectra exhibit a slightly red‐shifted emission with increasing content of 1 in the polymer chain. All the copolymers show high thermal stability ( T d5 > 436 °C), and the electrochemical stability toward oxidation is also observed. Particularly, the copolymer displays hole‐transporting ability for the stable green emission of Alq 3 when incorporated into the hole‐transporting layer of an electroluminescence device. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5816–5825, 2008