Efficient terpolymerization of ethylene and styrene with α‐olefins by aryloxo‐modified half‐titanocene‐based catalysts and cocatalyst systems

Abstract

Aryloxo‐modified half‐titanocenes, Cp′TiCl2(O‐2,6‐iPr2C6H3) [Cp′ = Cp* (1), tBuC5H4 (2)], catalyze terpolymerization of ethylene and styrene with α‐olefin (1‐hexene and 1‐decene) efficiently in the presence of cocatalyst, affording high‐molecular‐weight polymers with unimodal distributions (compositions). Efficient comonomer incorporations have been achieved by these catalysts. The content of each comonomer (α‐olefin, styrene, etc.) could be controlled by varying the comonomer concentration charged, and resonances ascribed to styrene and α‐olefin repeated insertion were negligible. The terpolymerization with p‐methylstyrene (p‐MS) in place of styrene also proceeded in the presence of [PhN(H)Me2][B(C6F5)4] and AliBu3 cocatalyst, and p‐MS was incorporated in an efficient matter, affording high‐molecular‐weight polymers with uniform molecular weight distributions. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2565–2574

Efficient Terpolymerization of Ethylene and Styrene with 1,7‐Octadiene by Aryloxo Modified Half‐Titanocenes–Cocatalyst Systems: Efficient Introduction of the Reactive Functionality

“…The catalytic activities by the Cp* analogue ( 1 ) in the terpolymerization decreased upon increasing the styrene concentration charged under the similar OD concentration conditions (runs 1–3), whereas the activity significantly increased upon increasing the OD concentration (runs 3–5). This is similar trend to our previous results in the ethylene/styrene/α‐olefin terpolymerization, whereas the activities were affected by ratio of the initial comonomer concentration used. The resultant polymers possessed relatively high molecular weights with unimodal molecular weight distributions ( = 7.6–21.9 × 10 4 g mol −1 , / = 1.65–2.51 runs 1–5).…”

“…Moreover, no melting temperatures were observed in the DSC thermograms in the resultant polymers, (see Supporting Information), clearly indicating that the resultant polymers possessed uniform compositions. These are similar observations to those in the terpolymerization of ethylene and styrene with α‐olefin …”

“…), are promising catalyst precursors, especially in terms of syntheses of new polymers by ethylene copolymerizations as mostly demonstrated by using the aryloxo or the ketimide analogues as the catalyst precursors . We reported that the aryloxo‐modified half‐titanocenes are highly effective not only for copolymerization of ethylene with styrene,,[12c], but also for terpolymerization of ethylene and styrene with α‐olefin . In this paper, we wish to present our explored results in terpolymerization of ethylene and styrene with 1,7‐octadiene using the aryloxo modified half‐titanocenes, Cp'TiCl 2 (O‐2,6‐ i Pr 2 C 6 H 3 ) [Cp′ = Cp* ( 1 ), t BuC 5 H 4 ( 2 ), 1,2,4‐Me 3 C 5 H 2 ( 3 )], in the presence of MAO cocatalyst (Scheme ).…”

A Greener Approach for Synthesis of Functionalized Polyolefins by Introducing Reactive Functionality into Ethylene Copolymers

“…Borate cocatalyst system was employed in this study, because use of MAO caused by-production of atacticpoly (p-MS) in large extent under these conditions. Complex 1 showed the higher activity than 5, however, the use of 5 afforded the copolymers with higher p-MS and α-olefin contents when the polymerization was proceeded under similar conditions [44]. The DSC thermograms in the polymers showed no melting temperature even with low styrene contents, and these samples do not have glass transition temperatures between 20˚C and 290˚C.…”

“…The terpolymerization of ethylene and p-MS with α-olefins could be achieved using 1 and 5, affording high molecular weight polymers with unimodal molecular weight distribution (Scheme 9) [44]. Borate cocatalyst system was employed in this study, because use of MAO caused by-production of atacticpoly (p-MS) in large extent under these conditions.…”