Ideal Polyethylene Nanocrystals


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OSICHOW, Anna, Christian RABE, Karsten VOGTT, Theyencheri NARAYANAN, Ludger HARNAU, Markus DRECHSLER, Matthias BALLAUFF, Stefan MECKING, 2013. Ideal Polyethylene Nanocrystals. In: Journal of the American Chemical Society. 135(31), pp. 11645-11650. ISSN 0002-7863. eISSN 1520-5126

@article{Osichow2013Ideal-24334, title={Ideal Polyethylene Nanocrystals}, year={2013}, doi={10.1021/ja4052334}, number={31}, volume={135}, issn={0002-7863}, journal={Journal of the American Chemical Society}, pages={11645--11650}, author={Osichow, Anna and Rabe, Christian and Vogtt, Karsten and Narayanan, Theyencheri and Harnau, Ludger and Drechsler, Markus and Ballauff, Matthias and Mecking, Stefan} }

The water-soluble catalyst precursor [[(2,4,6-(3,5-(CF<sub>3</sub>)<sub>2</sub>C<sub>6</sub>H<sub>3</sub>)<sub>3</sub>-C<sub>6</sub>H<sub>2</sub>)-N═C(H)-(3-(9-anthryl)-2-O-C<sub>3</sub>H<sub>3</sub>)-κ<sup>2</sup>-N,O]Ni(CH3)(TPPTS)] (TPPTS = tri(sodiumphenylsulfonate)phosphine) polymerizes ethylene to aqueous dispersions of highly ordered nanoscale crystals (crystallinity χ(DSC) ≥ 90%) of strictly linear polyethylene (<0.7 methyl-branches/1000 carbon atoms, M<sub>n</sub> = 4.2 × 10<sup>5</sup> g mol<sup>–1</sup>). SAXS in combination with cryo-TEM confirms this unusually high degree of order (χ(SAXS) = 82%) and shows the nanoparticles to possess a very thin amorphous layer on the crystalline lamella, just sufficient to accommodate a loop, but likely no entanglements. This ideal chain-folded structure is corroborated by annealing studies on the aqueous-dispersed nanoparticles, which show that the chain can move through the crystal as evidenced by lamella thickening without disturbing the crystalline order as concluded from an unaltered low thickness of the amorphous layers. These ideal chain-folded polyethylene nanocrystals arise from the crystallization in the confined environment of a nanoparticle and a deposition of the growing polymer chain on the crystal growth front as the chain is formed by the catalyst. Drechsler, Markus Ideal Polyethylene Nanocrystals Osichow, Anna Ballauff, Matthias 2013-08-26T14:58:04Z eng Drechsler, Markus Ballauff, Matthias Journal of the American Chemical Society ; 135 (2013), 31. - S. 11645-11650 deposit-license Vogtt, Karsten Harnau, Ludger Mecking, Stefan Narayanan, Theyencheri Rabe, Christian Vogtt, Karsten 2013-08-26T14:58:04Z Narayanan, Theyencheri Rabe, Christian Osichow, Anna Mecking, Stefan Harnau, Ludger 2013

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