Terpolymerization of Linear and Alicyclic α-Olefins with Norbornene and Ethylene by ansa-Metallocene Catalysts

Abstract

Ethylene−norbornene (E−N) terpolymerization experiments using the linear olefin 1-octene (O) or the alicyclic vinylcyclohexane (VCH) were conducted with two different ansa-metallocene compounds Zr(η5:η5-C5H4CPh2C13H8)Cl2] (1) and [Zr{(η5-2,5-Me2C5H2)2CHMe}Cl2] (2). The terpolymers obtained were investigated in detail by determining microstructure and termonomer contents by 13C NMR, molar masses, and thermal properties. Chain end group analysis gave insight into factors that influence termonomer insertion and chain termination. Terpolymer molar masses were lower than those of the corresponding copolymers, those from 1 being higher than those from 2. This is related to the lower tendency of catalyst 1 to give β-H elimination at a last enchained E unit as revealed from the low amount of vinyl chain end groups in 1H NMR spectra. In VCH terpolymers from catalyst 1, only vinylene end groups, arising from 2,1 VCH insertions after one last inserted E unit, are present. This along with the lower activity reveals that VCH insertion is more difficult with this catalyst than with catalyst 2. Furthermore, all experiments showed that in general VCH is more difficult to coordinate to an active catalyst than O. While catalyst 1 provides higher molar masses, catalyst 2 enables to reach higher activities, higher N and termonomer contents, and higher T g values. Finally, it was found that termonomer content greater than 3 mol % clearly affects T g values. Thus, preparation of norbornene−ethylene−α-olefin terpolymers with high T g and attractive molar masses was achieved in high yield by metallocene catalysts.

Synthesis of highly thermostable norbornene-isoprene-1-octene terpolymer with titanium catalyst

“…Such copolymers are called as cyclic olefin copolymers (COCs). The development of single‐site catalysts has realized the copolymerization not only with ethylene but also with α‐olefins, styrene, and olefins with functional groups …”

“…The addition of third comonomer is the efficient way to introduce unreactive comonomer. Synthesis of some cyclic olefin terpolymers are recently investigated . The aim of this work is to synthesize the NB‐enriched NB‐IP copolymer using fluorenylamido‐ligated titanium catalyst 1 , which showed very high activity for the (co‐)polymerizations of NB with α‐olefins and dicyclopentadiene with ethylene .…”

Terpolymerization of Substituted Cycloolefin with Ethylene and Norbornene by Transition Metal Catalyst

“…The opportunity of incorporating other olefins (as a third monomer) into the poly(ethylene- co -norbornene) backbone may lead to improvements in the mechanical or other physical properties of the polymer. There are only a few reports on terpolymerization of ethylene and norbornene [ 28 , 29 , 30 , 31 ]. The introduction of a termonomer, either a linear α-olefin, such as 1-octene (O), or an alicyclic α-olefin, like vinylcyclohexane, has been reported by Marconi et al [ 29 ], but a strong decrease of M w has been observed for both 1-octene and vinylcyclohexane.…”

“…There are only a few reports on terpolymerization of ethylene and norbornene [ 28 , 29 , 30 , 31 ]. The introduction of a termonomer, either a linear α-olefin, such as 1-octene (O), or an alicyclic α-olefin, like vinylcyclohexane, has been reported by Marconi et al [ 29 ], but a strong decrease of M w has been observed for both 1-octene and vinylcyclohexane. It was shown that 1-octene and vinylcyclohexane behave as chain termination/transfer agents, that is they act as reagents that both terminate and facilitate the reinitiation of a growing polymer chain [ 29 , 32 ].…”

Comonomer Effects of High a-Olefins in Metallocene Catalyzed Terpolymerization: Thermal Properties

“…Research on polymerization using a metallocene catalysts began with the identification of the structure of ferrocene by Wilkins and Fischer in 1952 and was developed further by Kaminsky in the 1980s 1,2 . In the case of copolymerization using a metallocene catalyst, preparing polymers with a narrow molecular weight distribution, high stereo-regularity and uniform comonomer incorporation is much easier than when a conventional Ziegler-Natta catalyst is used.…”