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

Abstract

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.

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

“…by ordinary metallocene catalysts gave oligomers [26,27,28]. Several examples [28,29,30,31,32,33] were known for synthesis of (ultra)high molecular weight poly(1-hexene)s by using [2,2-(O-4-Me-6- t Bu-C 6 H 3 ) 2 S]TiCl 2 (in the presence of specified modified MMAO) [31,32], or (C 5 HMe 4 ) 2 HfCl 2 (under ultrahigh pressure) [29]. One example was known for synthesis of isotactic poly(1-hexene)s with ultrahigh molecular weights by titanium complexes containing diamine bis(phenolate) ligands [30].…”

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

“…7,8 5-Ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB) satisfactorily meet these requirements. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The half-metallocene scandium complexes reported by Hou and his colleagues showed excellent catalytic activity for ethylene/norbornene (NBE) and ethylene/dicyclopentadiene (DCPD) copolymerization, with comonomer incorporation of 44 and 45 mol%, respectively. 20 For example, when Ph 2 -C(Flu)(Cp)ZrCl 2 (Cp ¼ C 5 H 5 , Flu ¼ uorenyl) was used in ethylene/VNB copolymerization, the catalytic activity could be up to 3520 kg per mol Zr per h with VNB incorporation of 32 mol%.…”

Synthesis of Ultrahigh Molecular Weight Polymers Containing Reactive Functionality with Low PDIs by Polymerizations of Long-Chain α-Olefins in the Presence of Their Nonconjugated Dienes by Cp*TiMe2(O-2,6-iPr2C6H3)–Borate Catalyst

“…However, reports for synthesis of UHMW polymers by polymerization of higher α-olefins (1-decene, 1-dodecene, 1-tetradecene, etc.) still have been limited [15,16,21,22], probably due to their preferred β-hydrogen elimination compared to the repeated insertion of monomer with a steric bulk (of alkane branching), as seen in ordinary metallocene catalysts yielding oligomers [21,23,24]. There are several examples for synthesis of (ultra)high molecular weight poly(1-hexene)s [21,[25][26][27] by using (C5HMe4)2HfCl2 (under ultrahigh pressure) [25], titanium complexes with diamine bis(phenolate) ligands [26].…”

“…still have been limited [15,16,21,22], probably due to their preferred β-hydrogen elimination compared to the repeated insertion of monomer with a steric bulk (of alkane branching), as seen in ordinary metallocene catalysts yielding oligomers [21,23,24]. There are several examples for synthesis of (ultra)high molecular weight poly(1-hexene)s [21,[25][26][27] by using (C5HMe4)2HfCl2 (under ultrahigh pressure) [25], titanium complexes with diamine bis(phenolate) ligands [26]. Synthesis of rather high molecular weights poly(α-olefin)s, mostly poly(1-hexene)s, using the other catalysts, have also been known [24,[29][30][31][32][33][34][35][36][37].…”

“…We reported that Cp*TiCl2(O-2,6i Pr2C6H3)-MAO catalyst afforded high molecular weight poly(α-olefin)s by polymerizations of 1-decene (DC), 1-dodecene (DD), 1-hexadecene, and 1octadecene [21]. It was then revealed that polymerizations of DC, DD, and 1-tetradecene (TD) proceeded in a quasi-living manner in the presence of Cp*TiMe2(O-2,6i Pr2C6H3) (1)-[Ph3C][B(C6F5)4] (borate) catalyst and Al cocatalysts at −30 to −50 °C, affording UHMW polymers (e.g., poly(DC): Mn = 7.04 × 10 5 , Mw/Mn = 1.37; poly(TD): Mn = 1.02 × 10 6 , Mw/Mn = 1.38); the polymerizations proceeded with rather high catalytic activities (activity at −30 °C: 4120-5860 kg-poly(DC)/mol-Ti•h) [22].…”