Copolymerization of vinylcyclohexane with ethene and propene using zirconocene catalysts

Abstract

Vinylcyclohexane (VCH) was copolymerized with ethene and propene using methylaluminoxane-activated metallocene catalysts. The catalyst precursor for the ethene copolymerization was rac-ethylenebis(indenyl)ZrCl 2 (1). Propene copolymerizations were further studied with C s -symmetric isopropylidene(cyclopentadienyl)(fluorenyl)ZrCl 2 (2), C 1 -symmetric ethylene(1-indenyl-2-phenyl-2-fluorenyl)ZrCl 2 (3), and \meso"-dimethylsilyl[3-benzylindenyl)(2-methylbenz[e]indenyl)]ZrCl 2 (4). Catalyst 1 produced a random ethene-VCH copolymer with very high activity and moderate VCH incorporation. The highest comonomer content in the copolymer was 3.5 mol %. Catalysts 1 and 4 produced poly(propene-co-vinylcyclohexane) with moderate to good activities [up to 4900 and 15,400 kg of polymer/(mol of catalyst  h) for 1 and 4, respectively] under similar reaction conditions but with fairly low comonomer contents (up to 1.0 and 2.0% for 1 and 4, respectively). Catalysts 2 and 3, both bearing a fluorenyl moiety, gave propene-VCH copolymers with only negligible amounts of the comonomer. The homopolymerization of VCH was performed with 1 as a reference, and low-molar-mass isotactic polyvinylcyclohexane with a low activity was obtained. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: [6569][6570][6571][6572][6573][6574] 2006

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

“…The spectra show the existence of various structural types of olefinic double bonds, associated with the presence of both terminal and internal unsaturations. The resonances of all these structural units, reported in Scheme and Table , were attributed by comparison of spectra of terpolymers with different termonomer content with those of ethylene copolymers, those with N prepared with the same catalysts and those with VCH and O reported in the literature. , Scheme describes the possible paths leading to terpolymer chain unsaturation with a last-inserted E, O, VCH, or N unit.…”

“…In case of 1-octene, the higher the concentration of termonomer, the lower the M w values of the resulting terpolymers (e.g., Table 1 entries 6, 10, and 11) in agreement with the general observation that the introduction of R-olefins in copolymerization reaction leads to a decrease of molar masses. [14][15][16] Comparatively much higher VCH feed concentration was required for terpolymers with similar termonomer incorporation level and lower M w values. Thus, probably O is easier to coordinate than VCH, but after coordination and/or insertion VCH causes easier chain termination.…”

“…The resonances of all these structural units, reported in Scheme 1 and Table 4, were attributed by comparison of spectra of terpolymers with different termonomer content with those of ethylene copolymers, those with N prepared with the same catalysts and those with VCH and O reported in the literature. 16,17 Scheme 1 describes the possible paths leading to terpolymer chain unsaturation with a last-inserted E, O, VCH, or N unit. As apparent in Figure 6a three different multiplets were detected.…”

“…The assignment of the resonances in the olefinic region of the 1 H NMR spectra showed some 1 H NMR chain-end structures peculiar of last-inserted vinylcyclohexane units, similar to those of poly(E-co-VCH) found in literature. 16 The signal at 4.99 ppm was attributed to vinylene chain end structures VCH-1.…”

Efficient Synthesis of Functionalized Polyolefin by Incorporation of 4-Vinylcyclohexene in Ethylene Copolymerization Using Half-Titanocene Catalysts

“…Therefore, the successful catalytic copolymerizations exhibiting high catalytic activities with efficient VCHen incorporations have never been reported so far. This seems to be probably somewhat related to the low efficiency of incorporation of vinyl group in VCHen as seen in the ethylene/vinylcyclohexane (VCH) copolymerization using ordinary metallocenes …”