Highly soluble polynorbornene prepared by an anilinonaphthoquinone-ligated nickel complex via coordination-insertion polymerization

Norbornene polymerization was conducted with 2-(2,6-diisopropylanilino)-1,4-naphthoquinone-ligated nickel complex (1) activated by B(C6F5)(3) and dried modified methylaluminoxane (dMMAO) in toluene at 40 degrees C. The 1-B(C6F5)(3) system showed higher activity than the 1-dMMAO system and gave higher molecular-weight polynorbornene via coordination-insertion polymerization. The solubility of the polymer obtained by 1-B(C6F5)(3) was also higher than that obtained by 1-dMMAO, and dissolved in cyclohexane even at room temperature. The self-standing films of the polynorbornene obtained by the B(C6F5)(3) system were prepared by the solution casting method with cyclohexane. The films thus prepared showed good transparency in the UV-visible region. The C-13 NMR spectra of the polymers indicated that the microstructures of the polynorbornenes were dependent on the activator used. The heat decomposition temperature, i.e., 10% weight loss, determined by TGA was 386 degrees C for the polymer obtained by 1-B(C6F5)(3) and 402 degrees C for that obtained by 1-dMMAO, respectively. (C) 2015 Elsevier B.V. All rights reserved.