• Polymer(Korea)
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• v.24 no.5
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• pp.646-655
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• 2000

Polymerizations of higher $\alpha$-olefins were carried out in toluene by using highly isospecific catalyst, rac-(EBI)M(NMe$_2$)$_2$ (EBI=1,2-ethylenebis-(1-indenyl); M=Zr(rac-1); M=Hf(rac-2)) In the presence of Al(i-Bu)$_3$/[Ph$_3$C][B($C_{6}F_{5}$)$_4$]. The polymerization of high $\alpha$-olefin showed high activity and similar polymerization behavior. The polymerization activity was affected by both monomer size and lateral size of polymer chain. The conversion of monomer to polymer decreases with the increased lateral size in the order of 1-pentene>1-hexene>1-octene>1-decene. The same dependences of melting behavior and intrinsic viscosity of polyolefin on lateral size were observed according to the results obtained by differential scanning calorimetry and intrinsic viscosity. All poly($\alpha$-olefin)s showed very high isotacticity (triad) and the isotacticity increases in the order of poly(1-pentene)$^1H$ NMR and Raman spectra analysis showed that chain transfer to cocatalyst, which generates saturated methyl groups, Is a main chain termination. The $\beta$-hydride eliminations, which generate unsaturated vinylidene, tri-substituted, and vinylene end group. are found to be minor chain terminations.

• Elastomers and Composites
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• v.48 no.4
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• pp.269-275
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• 2013

In this study, we prepared poly(ethylene-ter-1-hexene-ter-divinylbenzene) using various metallocene catalysts with trityl tetrakis(pentafluorophenyl)borate/triisobutylaluminium cocatalysts system. We tried rac-$Et(Ind)_2ZrCl_2$, rac-$SiMe_2(Ind)_2ZrCl_2$, and rac-$SiMe_2(2-Me-Ind)_2ZrCl_2$ to choose optimum metallocene catalyst, comparing with catalytic activity, molecular weight, molecular weight distribution of the terpolymers. To study the effects of chain length of high ${\alpha}$-olefins on the terpolymerization, we synthesized the terpolymers using 1-hexene, 1-octene, 1-decene or 1-dodecene. We characterized chemical composition, thermal properties, and mechanical properties of the terpolymers.

• Polymer(Korea)
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• v.35 no.6
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• pp.505-512
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• 2011

Effects of structural features of 4 dinuclear constrained geometry catalysts having paraxylene derivative bridge (DCGC) on copolymerization of ethylene and 1-hexene were investigated. The bridges of three catalysts have para-xylene backbone with a different substituent at benzene ring. The substituents were hydrogen (Catalyst 1), isopropyl (Catalyst 2), n-hexyl (Catalyst 3) and 1-octyl (Catalyst 4). It was found that Catalyst 1 having hydrogen as a substituent exhibited the greatest activity among the four dinuclear CGCs. On the other hand, Catalyst 2 containing isopropyl as a substituent showed the smallest activity. Very interestingly, Catalyst 2 was able to produce about 6 times higher molecular weight polymer than Catalyst 3 and 4. Catalyst 3 and 4 having a long alkyl chain substituent revealed the biggest comonomer response to generate polyethylene copolymer containing more than 40% 1-hexene contents. These results suggest that the control of the substituent of para-xylene bridge of dinuclear CGC can provide a proper method to adjust the microstructure of polyethylene copolymers.

• Elastomers and Composites
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• v.48 no.1
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• pp.85-91
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• 2013

In this study, we synthesized a terpolymer consisting of ethylene, 1-hexene, and styrenic monomer using a metallocene catalyst and cocatalyst ststem. The styrenic monomers empolyed as the third monomer were styrene, p-methylstyrene, and 4-tert-butylstyrene. The structure and composition of the terpolymers were characterized using $^{13}C$ NMR and $^1H$ NMR. Catalytic activity, polymer yield, molecular weight and molecular weight distribution of the terpolymers were analyzed. We also determined the glass transition temperature(Tg), crystallinity and thermal properties of the terpolymers by DMA, WAXS and TGA.

• Elastomers and Composites
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• v.51 no.3
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• pp.188-194
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• 2016

In this study, novel quaternary plastomers consisting of ethylene, 1-hexene, high ${\alpha}$-olefin, and divinylbenzene were prepared using Zr metallocene catalyst, borate type cocatalyst, and tri-isobutylaluminium. The molar ratio changes of 1-hexene and high ${\alpha}$-olefin (1-octene, 1-decene, and 1-dodecene) had an effect on the properties of the quaternary plastomers. The structure of the quaternary plastomers was characterized using $^1H$ NMR. Molecular weight properties, crystallinity, and thermal properties of the plastomers were determined by GPC, WAXS, and DMA, respectively. Compared with the terpolymers prepared in our previous study, molecular weight and molecular weight distribution of the quaternary polymers were very similar, whereas glass transition temperature ($T_g$) was very low. Also, hardness and tensile properties of the quaternary plastomers were measured.

• Macromolecular Research
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• v.14 no.2
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• pp.240-244
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• 2006

• Polymer(Korea)
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• v.31 no.6
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• pp.497-504
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• 2007

We have prepared the dinuclear half-sandwich CGC(constrained geometry catalyst) with polymethylene bridge $[Zr(({\eta}^5\;:\;{\eta}^1-C_9H_5SiMe_2NCMe_3)Me_2)_2\;[(CH_2)_n]$ [n=6(4), 9(5), 12(6)] by treating 2 equivalents of MeLi with the corresponding dichlorides compounds. To study the catalytic behavior of the dinuclear catalysts we conducted copolymerization of ethylene and 1-hexene in the presence of three kinds of boron cocatalysts, $Ph_3C^+[B(C_6F_5)_4]^-\;(B_1),\;B(C_6F_5)_3\;(B_3)$, and $Ph_3C^+[(C_6F_5)_3B-C_6F_4-B(C_6F_5)_3]^{2-}\;(B_2)$. It turned out that all active species formed by the combination of three dinuclear CGCs with three cocatalyst were very efficient catalysts for the polymerization of olefins. The activities increase as the bridge length of the dinuclear CGCs increases. At the same time the dinuclear cocatalyst exhibited the lowest activity among three cocatalysts. The prime observation is that the dinuclear cocatalyst gave rise to the formation of the copolymers with the least branches on the polyethylene backbone.

• Elastomers and Composites
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• v.47 no.4
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• pp.329-335
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• 2012

In this study, we synthesized poly(ethylene-ter-high ${\alpha}$-olefin-ter-p-methylstyrene) using Zr metallocene catalyst/borate type cocatalyst system. Various effects of the high ${\alpha}$-olefin (1-hexene, 1-octene, 1-decene, and 1-dodecene) were observed. The structure and composition of the terpolymers were characterized using $^{13}C$ NMR and $^1H$ NMR. Catalytic activity, polymer yield, molecular weight and molecular weight distribution were analyzed according to the chain length of high ${\alpha}$-olefin. We determined morphology, crystallinity and thermal properties of the terpolymers.

• Journal of the Korean Graphic Arts Communication Society
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• v.1 no.1
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• pp.57-60
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• 1983

Among the gelatin hardness for photographic emulaion, the formaldehyde, dialdehydes, n-Methylol compounds, ketones, carbonylic acid and carbamic acid derivatives, and s-Triazine derivatives were studied The greater purts of hardeners formed cross-link by the reaction with E-Amino group in the lysine and OH group in the hydroxylysine. Glutaraldehyde produced most stable cross-link due to the formation of pyridinum ion. 2.5- hexanedione and 3-hexene-2,5-dione possible to use as the ketone hardner. The sodium salt of 2.4-dichloro-6-hydroxy-S-Triazine was newly developed as the olefinic hardners for emulsion.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.223-223
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• 2006

A Suzuki-coupling route is developed for preparation of ortho-phenylene-bridged Cp/amido complexes, one of which shows higher activity, higher 1-hexene incorporation, and higher molecular weight than the silylene-bridged standard CGC $[Me_{2}Si({\eta}^{5}-Me_{4}Cp)(N^{t}Bu)]TiCl_{2}$.