Synthesis of ultrahigh molecular weight polymers by homopolymerisation of higher α-olefins catalysed by aryloxo-modified half-titanocenes

RSC Advances ◽  
2016 ◽  
Vol 6 (20) ◽  
pp. 16203-16207 ◽  
Author(s):  
Kotohiro Nomura ◽  
Sarntamon Pengoubol ◽  
Wannida Apisuk
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molecular Weight Distributions ◽  
High Molecular Weight Polymers ◽  
Ultrahigh Molecular Weight ◽  
Weight Distributions ◽  
Ultra High Molecular Weight

Polymerisations of 1-dodecene, 1-hexadecene, 1-octadecene by Cp*TiX2(O-2,6-iPr2C6H3) – cocatalysts afforded (ultra)high molecular weight polymers with unimodal molecular weight distributions.

Electrospinning of Ultrahigh-Molecular-Weight Polyethylene Nanofibers

2008 ◽  
Vol 1083 ◽  
Author(s):  
Dmitry M. Rein ◽  
Yachin Cohen ◽  
Avner Ronen ◽  
Eyal Zussman ◽  
Kim Shuster
Keyword(s):  
Molecular Weight ◽  
Dielectric Constant ◽  
Elevated Temperature ◽  
High Molecular Weight ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Ultrahigh Molecular Weight ◽  
Electrospinning Method ◽  
Surface Modified ◽  
First Time ◽  
Ultra High Molecular Weight

ABSTRACTThe electrospinning method was employed to fabricate extremely fine nanofibers of ultra-high molecular weight polyethylene (UHMWPE) for the first time, using a mixture of solvents with different dielectric constant and conductivity. A novel experimental device for elevated temperature electrospinning of highly volatile and quickly crystallizing polymer solutions and melts was developed. The possibility to produce the highly oriented nanofibers from ultra-high molecular weight polymers suggests new ways for fabrication of ultra-strong, porous, surface modified fibers and single-component nanocomposite yarn with improved properties.

A Comparison of the Wear of Cross-Linked Polyethylene against Itself with the Wear of Ultra-High Molecular Weight Polyethylene against Itself

1996 ◽  
Vol 210 (4) ◽  
pp. 297-300 ◽  
Author(s):  
T J Joyce ◽  
A Unsworth
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Contact Stress ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Measurement Point ◽  
Wear Factor ◽  
Ultrahigh Molecular Weight ◽  
Ultra High Molecular Weight ◽  
Wear Tests

Wear tests were carried out on reciprocating pin-on-plate machines which had pins loaded at 10 N and 40 N. The materials tested were irradiated cross-linked polyethylene sliding against itself, irradiated ultra-high molecular weight polyethylene sliding against itself and non-irradiated ultra-high molecular weight polyethylene sliding against itself. After 153.5 km of sliding, the non-irradiated ultrahigh molecular weight polyethylene plates and pins showed mean wear factors under 10 N loads, or a nominal contact stress of 0.51 MPa, of 84.0 × 10−6 mm3/N m for the plates and 81.3 × 10−6 mm3/N m for the pins. Under 40 N loads, or a nominal contact stress of 2.04 MPa, the non-irradiated ultra-high molecular weight polyethylene pins sheared at 22.3 km. At the last measurement point prior to this failure, 19.1 km, wear factors of 158 × 10−6mm3/N m for the plates and 85.0 × 10−6 mm3/N m for the pins had been measured. After 152.8 km, the irradiated ultra-high molecular weight polyethylene plates and pins showed mean wear factors under 10 N loads of 59.8 × 10−6 mm3/N m for the plates and 31.1 × 10−6 mm3/N m for the pins. In contrast, after 150.2 km, a mean wear factor of 0.72 × 10−6 mm3/N m was found for the irradiated cross-linked polyethylene plates compared with 0.053 × 10−6 mm3/N m for the irradiated cross-linked polyethylene pins.

Separating ultra-high molecular weight polymers on monolithic capillary columns

2013 ◽  
Vol 87 (2) ◽  
pp. 308-313 ◽  
Author(s):  
E. N. Viktorova ◽  
A. A. Korolev ◽  
V. A. Orekhov ◽  
A. Yu. Kanat’eva ◽  
A. A. Kurganov
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Capillary Columns ◽  
High Molecular Weight Polymers ◽  
Monolithic Capillary Columns ◽  
Ultra High Molecular Weight

scholarly journals Synthesis of ultra‐high molecular weight polymers by controlled production of initiating radicals

2019 ◽  
Vol 57 (18) ◽  
pp. 1922-1930 ◽  
Author(s):  
Amin Reyhani ◽  
Stephanie Allison‐Logan ◽  
Hadi Ranji‐Burachaloo ◽  
Thomas G. McKenzie ◽  
Gary Bryant ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
High Molecular Weight Polymers ◽  
Ultra High Molecular Weight

An unsymmetrical binuclear iminopyridine-iron complex and its catalytic isoprene polymerization

2020 ◽  
Vol 56 (62) ◽  
pp. 8846-8849 ◽  
Author(s):  
Liang Wang ◽  
Xiaowu Wang ◽  
Hongbin Hou ◽  
Guangqian Zhu ◽  
Zhenyu Han ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Iron Complex ◽  
Binuclear Complexes ◽  
High Molecular Weight Polymers ◽  
Ultra High Molecular Weight ◽  
Isoprene Polymerization

A series of chloride-bridged unsymmetrical Fe(ii)-HS/Fe(ii)-LS binuclear complexes has been developed, which can efficiently catalyze isoprene polymerization with 0.00025 mol% loading, delivering ultra-high molecular weight polymers.

scholarly journals Solution-processable and functionalizable ultra-high molecular weight polymers via topochemical synthesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher L. Anderson ◽  
He Li ◽  
Christopher G. Jones ◽  
Simon J. Teat ◽  
Nicholas S. Settineri ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
Crystal Packing ◽  
Polymerization Reaction ◽  
Capacitive Energy Storage ◽  
Topochemical Polymerization ◽  
Microscopy Technique ◽  
High Molecular Weight Polymers ◽  
Ultra High Molecular Weight

AbstractTopochemical polymerization reactions hold the promise of producing ultra-high molecular weight crystalline polymers. However, the totality of topochemical polymerization reactions has failed to produce ultra-high molecular weight polymers that are both soluble and display variable functionality, which are restrained by the crystal-packing and reactivity requirements on their respective monomers in the solid state. Herein, we demonstrate the topochemical polymerization reaction of a family of para-azaquinodimethane compounds that undergo facile visible light and thermally initiated polymerization in the solid state, allowing for the first determination of a topochemical polymer crystal structure resolved via the cryoelectron microscopy technique of microcrystal electron diffraction. The topochemical polymerization reaction also displays excellent functional group tolerance, accommodating both solubilizing side chains and reactive groups that allow for post-polymerization functionalization. The thus-produced soluble ultra-high molecular weight polymers display superior capacitive energy storage properties. This study overcomes several synthetic and characterization challenges amongst topochemical polymerization reactions, representing a critical step toward their broader application.

scholarly journals Synthesis of Ultrahigh Molecular Weight Polymers with Low PDIs by Polymerizations of 1-Decene, 1-Dodecene, and 1-Tetradecene by Cp*TiMe2(O-2,6-iPr2C6H3)–Borate Catalyst

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1634 ◽  
Author(s):  
Kotohiro Nomura ◽  
Sarntamon Pengoubol ◽  
Wannida Apisuk
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Low Temperatures ◽  
Catalytic Activities ◽  
High Molecular Weight Polymers ◽  
Ultrahigh Molecular Weight ◽  
High Molecular Weight Poly

Polymerizations of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) by Cp*TiMe2(O-2,6-iPr2C6H3) (1)–[Ph3C][B(C6F5)4] (borate) catalyst have been explored in the presence of Al cocatalyst. The polymerizations of DC and DD, in n-hexane containing a mixture of AliBu3 and Al(n-C8H17)3, proceeded with high catalytic activities in a quasi-living manner, affording high molecular weight polymers (activity 4120–5860 kg-poly(DC)/mol-Ti·h, Mn for poly(DC) = 7.04–7.82 × 105, after 20 min at −30 °C). The PDI (Mw/Mn) values in the resultant polymers decreased upon increasing the ratio of Al(n-C8H17)3/AliBu3 with decreasing the activities at −30 °C. The PDI values also became low when these polymerizations were conducted at low temperatures (−40 or −50 °C); high molecular weight poly(DD) with low PDI (Mn = 5.26 × 105, Mw/Mn = 1.16) was obtained at −50 °C. The TD polymerization using 1–borate–AliBu3 catalyst (conducted in n-hexane at −30 °C) afforded ultrahigh molecular weight poly(TD) (Mn = 1.02 × 106, Mw/Mn = 1.38), and the PDI values also decreased with increasing the Al(n-C8H17)3/AliBu3 ratio.

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