Ti complex catalysts including thiobisphenoxy group as a ligand for olefin polymerization

Abstract

Absaact: Titanium complexes were prepared by the reaction of 2,2'-thiobis(6-mbutyl-4-methylphenol) (TBP) with TiC1, or Ti(OPf),.These complexes in combination with methyalumoxane as cocatalyst are highly active towards ethylene and propene, giving polymers having high molecular weights. The polymerization activities for ethylene-and propene are comparable to those of Cp2ZrC MA0 catalyst. Polypropylene obtained had extremely high molecular weigk (Mw>6 million) and low regioregularity (30% of head-to-head and tail-to-tail linkages). Highly syndiotactic polystyrene was obtained with these catalysts with activity up to 27 kg polymer per g Ti and hour. Copolymerization of styrene with ethylene gave highly alternating copolymer with isotactic styrene units. These catalysts are also active toward both conjugated and nonconjugated dienes such as butadiene and 1,5-hexadiene. Polybutadiene had mainly cis-l,4-strucm e (98%). The structure of poly(1J-hexadiene) is rather complicated, which is quite different from that prepared with heterogeneous Tic& catalysts.INTRODUCTION Titanocenes and titanium tetraalkoxides combined with an alkylaluminium compound can polymerize olefins.') However, the catalytic activities are very low compared with that of commercial catalysts, i.e., Tic4 and MgCG-supported catalyst. Kaminsky and Sinn found that titanocene and zirconocene compounds, when they are combined with methylalumoxane (MAO) instead of alkylaluminium compounds, become extremely active toward ethylene, giving polyethylene with high molecular weight.".') They also found that these catalyst systems are also active toward propene, but the polypropylene obtained had very low molecular weight!) Afterwards, Ewen?)*@ and Kaminsky') showed that racemic m-metallocene c o m p o~n d~)~~) with MA0 gives isotactic polypropylene. However, the molecular weight of the resulting polypropylenes was still low.

Catalytic systems Me2SiCp*NtBuMX2/(CPh3)(B(C6F5)4) (M?Ti, X?CH3, M?Zr, X?iBu) in copolymerization of ethylene with styrene

“…4) give the values of 9 and 0.04, respectively. The value of r E ϫ r S Ϸ 0.4 reflects the alternating comonomers incorporation being in accord with data by Kakugo et al, 13 Zambelli et al, 31 and Oliva et al 42,43 reported for E/S copolymerization catalyzed with MAO-treated mono-Cp titanium complexes and ansazirconocenes. Contradictory, random comonomer incorporation catalyzed with MAO-treated chelatelike titanium complexes was communicated elsewhere.…”

“…The 13 C-NMR spectra of several E/S copolymers obtained at a different ethylene pressure are presented in Figure 9 (spectra a-c). The sample with the lowest styrene content (ϳ 6 mol %, entry 13) showed 13 C resonance peaks corresponding to isolated styrene units: T ␦␦ (46.6 ppm), S ␣␦ (37.3 ppm), S ␤␦ (28.0 ppm), and S ␦␦ (30.1 ppm) (Fig. 9, spectrum a).…”

“…The investigation mainly invented the design of sPS, [2][3][4][5][6][7][8][9][10][11][12] ethylene/ styrene (E/S) copolymers, [13][14][15][16][17][18][19][20] co-and terpolymers with ␣-olefins and other monomers, [21][22][23] and copolymers of substituted styrenes. 24,25 Common properties of metallocene-based catalysts applicable for styrene polymerizing will be pointed out.…”

Alkylmono(cyclopentadienyl)titanium Complexes Containing the 2,2′‐Methylenebis(6‐tert‐butyl‐4‐methylphenoxido) Ligand – Studies on the Nature of the Catalytic Species Present in α‐Olefin Polymerisation Processes

“…1 H NMR (300 MHz, C 6 D 6 , 25°C): δ = 7.28 (m, 5 H, CH 2 Ph), 7.11, 7.01 (AAЈ spin system, 2 ϫ 2 H, Ph), 6 [TiPh(η 5 -C 5 H 5 )(η 2 -mbmp)] (6a, 6b, 6c): A 1.8  solution of LiPh in diethyl ether (0.35 mL, 0.62 mmol) was added at -78°C to a solution of 1 (0.30 g, 0.62 mmol) in hexane (50 mL). The reaction mixture was slowly warmed to room temperature and stirred for 12 h. The resulting solution was concentrated under vacuum and a brown oily solid was obtained; spectroscopic analysis revealed a mixture of three isomers 6a, 6b and 6c.…”

Propylene Polymerization Using ansa‐Zirconocenes with Water/Pentafluorophenol‐Modified Methylaluminoxane

“…[11][12][13][14][15][16][17][18][19][20] Recently, several research groups have studied the effect of the cocatalyst on the stereoregularity of propylene polymerization. [17,21,22] We have reported the enhancement of productivity, stereoregularity, and regioregularity as well as increased molecular weight of 1-butene polymerization with a 2,2-thiobis(phenoxy)titanium complex (1) [23][24][25][26] by isobutylmethylaluminoxane (MMAO) modification using water [27] or both water and pentafluorophenol. [28] In these studies, we claim that the addition of water and pentafluorophenol induces the structural and electrical changes in the aluminoxane and the reduction of ''free'' trimethylaluminum (TMA).…”