Homo- and copolymerization of 5-ethylidene-2-norbornene with ethylene by [2-C5Me4-4,6-tBu2C6H2O]TiCl2/AliBu3/Ph3CB(C6F5)4 catalyst system and epoxidation of the resulting copolymer

Synthesis and structures of adamantyl-substituted constrained geometry cyclopentadienyl–phenoxytitanium complexes and their catalytic properties for olefin polymerization

“…In addition, the increase in the initial ENB concentration results in an increase in the yield and intrinsic viscosity of the PENB. These results are similar to those observed in the ENB polymerization with 11/TIBA/B catalyst system [30]. As observed for the ethylene/1-hexene copolymerization, the catalytic activity of the 10/TIBA/B catalyst system is obviously lower than that of 8 and 9/TIBA/B catalyst systems under similar conditions.…”

“…In these 1 H NMR spectra, obvious differences can be seen in the region of 5.5e6.2 ppm. According to literatures [30,45], the resonances between 6.0 and 6.2 ppm are for the protons of the endocyclic double bond and the resonances between 4.9 and 5.8 ppm are for the double bond protons of the ethylidene group. The 1 H NMR spectra of these PENB samples show that ENB is polymerized regioselectively by the 8e10/TIBA/B catalyst systems through the endocyclic double bond with the ethylidene group unreacted [45e47].…”

“…The results, together with those from 11/TIBA/B catalyst system [30], are summarized in Table 4. As seen above for the ethylene/1-hexene copolymerization and the ENB polymerization, the catalytic activity of 8 and 9/TIBA/B catalyst systems is higher than that of 10/TIBA/B catalyst system under the same conditions.…”

“…To further improve the catalytic property of this type of catalysts, we have synthesized several new titanium complexes of type II bearing a bulky adamantyl substituent at the ortho-position of the phenoxy group in their ligands. It was found that these new complexes, upon activation with Al i Bu 3 and Ph 3 CB(C 6 F 5 ) 4 (TIBA/B), exhibit higher catalytic activity and produce polymers with higher molecular weights for ethylene/1-hexene (E/H) copolymerization, and show better comonomer incorporation ability in E/ENB copolymerization and higher tacticity-control ability in ENB polymerization than the known complexes of this type [30]. In this paper, we wish to report the synthesis and structural characterization of the new titanium complexes, [h 5 : h 1 -2-C 5 Me 4 -4-R-6-Ad-C 6 H 2 O]TiCl 2 [Ad ¼ adamantyl, R ¼ Me (8), t Bu (9)] and [h 5 : h 1 -2-C 5 H 2 Ph 2 -4-t Bu-6-Ad-C 6 H 2 O]TiCl 2 (10), as well as the results from the ENB polymerization, the E/H and E/ENB copolymerization catalyzed by these complexes in the presence of Al i Bu 3 and Ph 3 CB(C 6 F 5 ) 4 .…”

“…We and other groups have developed a number of CGC catalysts of the type [h 5 : h 1 -C 5 Me 4 -ArO]TiCl 2 (II in Chart 1) and found that these catalysts show high catalytic activity in ethylene/a-olefin copolymerization though they produce copolymers with relatively low molecular weights due probably to their ligands being not bulky enough [16e19]. In addition, this type of catalysts were found to show good catalytic properties in the copolymerization of ethylene with cyclo-olefins such as norbornene or 5-ethylidene-2-norbornene (ENB) and produce copolymers with relatively high molecular weights and comonomer incorporation [29,30]. To further improve the catalytic property of this type of catalysts, we have synthesized several new titanium complexes of type II bearing a bulky adamantyl substituent at the ortho-position of the phenoxy group in their ligands.…”