Rare earth catalyst and controllable polymerization method for conjugated diene in arene medium

A technology of rare earth catalysts and conjugated diolefins, applied in the field of rare earth catalysts, can solve the problems of reducing catalyst activity and stereoselectivity, and achieve high catalytic activity and high directional selectivity

Active Publication Date: 2014-05-14
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Oriented polymerization of conjugated dienes (such as butadiene and isoprene) under the action of rare earth catalysts can obtain polybutane with high cis-1,4 structure content (cis-1,4 content > 95%) Alkene or polyisoprene, the solvent usually used is C 4 -C 9 The use of saturated alkanes or naphthenes, and the use of aromatics can lead to a significant reduction in catalyst activity and stereoselectivity

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Under the protection of nitrogen, with hexane as solvent medium, add 0.80mmol neodymium 2-ethylhexanoate, 0.16mmol 2-ethylhexanoate, 6.4mmol chloroform, 0.17mmol ethanol, 15.9mmol triisobutylaluminum Al (i-Bu) 3 and 0.1 mmol of diisobutylaluminum hydride, mixed uniformly and then reacted at 40°C for 2 hours to form a homogeneous catalyst system.

[0027] Under the protection of nitrogen, add 27mL of butadiene / styrene solution ([Bd]=3.1mol / L) to a 100mL dry polymerization reactor, and then add the above catalyst, wherein the moles of component A and butadiene monomer The ratio is 1.6×10 -3 After mixing evenly, polymerize at 10°C for 4.5h, terminate the reaction with an ethanol solution containing antioxidant-264 (1%), remove the solvent and unreacted monomers, and dry in a vacuum oven at 50°C until constant weight . Polybutadiene yield is 85%, polybutadiene weight-average molecular weight (M w ) is 4.1×10 5 , molecular weight distribution index (M w / M n ) is 3.8,...

Embodiment 2

[0029] Under nitrogen protection, with hexane as the solvent medium, add 0.8mmol neodymium 2-ethylhexanoate, 1.3mmol 2-ethylhexanoate, 2.4mmol 1,1,1-trichloroethane, 0.07mmol ethanol, 12.6 mmol Triisobutylaluminum Al(i-Bu) 3 and 0.2mmol diisobutylaluminum hydride and 1.6mmol butadiene, mixed for 1 evenly and then reacted at 50°C for 5h to form a homogeneous catalyst system.

[0030] Under the protection of nitrogen, add 27mL of butadiene / styrene solution ([Bd]=3.1mol / L) to a 100mL dry polymerization reactor, and then add the above catalyst, wherein the moles of component A and butadiene monomer The ratio is 4.3×10 -4 , After mixing evenly, polymerize at 20°C for 4.5h. The termination reaction and aftertreatment are the same as in Example 1. Polymer yield was 76%, M w 3.2×10 5 ,M w / M n 3.1, the cis-1,4 structure content is 98.2%, and the polymer basically does not contain styrene units.

Embodiment 3

[0032] Under nitrogen protection, with hexane as solvent medium, add 0.80mmol neodymium 2-ethylhexanoate, 0.16mmol 2-ethylhexanoate, 6.4mmol chloroform, 0.005mmol methyl trichlorobenzoate, 0.51mmol Ethanol, 15.9mmol triisobutylaluminum Al(i-Bu) 3 and 0.1 mmol of diisobutylaluminum hydride, mixed uniformly and then reacted at 40°C for 2 hours to form a homogeneous catalyst system.

[0033] Under the protection of nitrogen, add 27mL of butadiene / α-methylstyrene solution ([Bd]=3.1mol / L) to a 100mL dry polymerization reactor, and then add the above catalyst, wherein component A and butadiene The molar ratio of monomers is 1.6×10 -3 , After mixing evenly, polymerize at 10°C for 4.5h. The termination reaction and aftertreatment are the same as in Example 1. Polymer yield was 97%, M w 2.9×10 5 ,M w / M n 3.2, the cis-1,4 structure content is 99.4%, and the polymer basically does not contain α-methylstyrene units.

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Abstract

The invention relates to a rare earth catalyst and a controllable polymerization method for conjugated diene in an arene medium. A rare earth metal carboxylate-based composite catalyst is adopted for catalyzing conjugated diene polymerization in the arene medium under the protection of inert gas to prepare high molecular weight high cis polyconjugated diene rubber. The rare earth catalyst has high catalytic activity and high directional selectivity for polymerizing the conjugated diene in the arene medium, ensures that the monomer conversion rate of the conjugated diene is over 70 percent and even over 90 percent, the cis-content of constitutional units of the polyconjugated diene is over 97 percent and is over 99 percent particularly, the obtained polyconjugated diene has the weight-average molecular weight (Mw) of 2.0*10<5>-1.5*10<6>, and the content of vinylarene participating in copolymerization is less than 1 percent (mol) and even cannot be tested.

Description

Technical field: [0001] The invention relates to a rare-earth catalyst, especially a rare-earth catalyst used for the polymerization of conjugated diene in aromatic medium and a controllable polymerization method of conjugated diene in aromatic medium. Background technique: [0002] Oriented polymerization of conjugated dienes (such as butadiene, isoprene) under the action of rare earth catalysts can obtain polybutane with high cis-1,4 structure content (cis-1,4 content > 95%) Alkene or polyisoprene, the solvent usually used is C 4 -C 9 The use of saturated alkanes or naphthenes, and the use of aromatics can lead to a significant reduction in catalyst activity and stereoselectivity. In the rare earth catalyzed copolymerization system of conjugated diene and styrene, usually the catalyst activity is reduced, the molecular weight of the polymerization product is reduced, the cis-1,4 structure content of the butadiene chain is also reduced, and the resulting butadiene-styr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F4/54C08F4/52C08F136/04C08F136/06C08F136/08
Inventor 吴一弦朱寒零萍周为为
Owner BEIJING UNIV OF CHEM TECH
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