Bis(α-diimine) single nickel(ii) catalyst with strong electron-withdrawing group was applied to catalyze polymerization and copolymerization of norbornene and butyl methacrylate.
Crosslinked hydroxyl-conductive copolymer/silica composite membranes based on addition-type polynorbornene, poly(dodoxymethylene norbornene-co-norbornene-3-(trimethylpropyl ammonium)-functionalized silica (QP(DNB/ NB-SiO 2 ), were prepared by a sol-gel method. Copolymer composite membranes with different degree of quaternary ammonium functional silica, designated as QP(DNB/NBSiO 2 -X) (X 5 5, 10, 15 and 25 wt%, respectively), displayed good dimensional stabilities with low in-plane swelling rate of 1.32-3.7%, good mechanical properties with high elastic modulus of 605.4-756.8 MPa and high tensile strength of 13.2-20 Mpa. The achieved copolymer composite membranes could self-assemble into a microphase-separated morphology with randomly oriented long-range aliphatic chain/cylinder ionic channels that were imbedded in the hydrophobic PNB matrix. Among these membranes, the QP(DNB/NB-SiO 2 -25) showed the parameter with ionic conductivity of 9.33 3 10 23 S cm 21 , methanol permeability of 2.89 3 10 27 cm 2 s 21 , and ion-exchange capacity(IEC) of 1.19 3 10 23 mol g 21 . A current density of 82.3mA cm 22 , the open circuit voltage of 0.65 V and a peek power density of 32 mW cm 22 were obtained. POLYM. ENG. SCI., 58:13-21, 2018.
Blend proton exchange membranes (BPEMs) were prepared by blending sulfonated poly(aryl ether nitrile) (SPAEN) with phosphorylated poly(vinylbenzyl chloride) (PPVBC) and named as SPM-x%, where x refers to the proportion of PPVBC to the weight of SPAEN. The chemical complexation interaction between the phosphoric acid and sulfonic acid groups in the PPVBC–SPAEN system resulted in BPEMs with reduced water uptake and enhanced mechanical properties compared to SPAEN proton exchange membranes. Furthermore, the flame retardancy of the PPVBC improved the thermal stability of the BPEMs. Despite a decrease in ion exchange capacity, the proton conductivity of the BPEMs in the through-plane direction was significantly enhanced due to the introduction of phosphoric acid groups, especially in low relative humidity (RH) environments. The measured proton conductivity of SPM-8% was 147, 98, and 28 mS cm−1 under 95%, 70%, and 50% RH, respectively, which is higher than that of the unmodified SPAEN membrane and other SPM-x% membranes. Additionally, the morphology and anisotropy of the membrane proton conductivities were analyzed and discussed. Overall, the results indicated that PPVBC doping can effectively enhance the mechanical and electrochemical properties of SPAEN membranes.
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