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Anionic polymerization method for synthesing isotactic polystyrene

An isotactic polystyrene and anionic polymerization technology, applied in the field of polymer compound synthesis and anionic polymerization, can solve the problems of long reaction time, no industrial value, low monomer conversion rate, etc., shorten the polymerization time, and is conducive to industrialization applied effect

Inactive Publication Date: 2010-01-13
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Takayuki Makino[Takayuki Makino and Thieo E.Hogen-Esch.Anionic Synthesis of HighlyIsotactic Polystyrene in Hexane in the Presence of Lithium Hydroxides.Macromolecules 1999,32,5712-5714] etc. use n-hexane as solvent, tert-butyllithium, 3,3 -Dimethyl-1,1-diphenyl-1-butyllithium or polyisoprenyllithium is used as an initiator, the polymerization temperature is -30°C or lower than -30°C, and in the presence of LiOH, the synthesis Polystyrene with high isotactic content (about 70%) is produced, but the reaction time is long, generally more than 24 hours; the monomer conversion rate is low, the highest is only 78%, and has no industrial value

Method used

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  • Anionic polymerization method for synthesing isotactic polystyrene
  • Anionic polymerization method for synthesing isotactic polystyrene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Take five 250ml polymerization flasks, bake them at high temperature, and replace nitrogen for more than 3 times. Use a pipette to add 100ml cyclohexane to each polymerization bottle, add 0.1mmol of barium dodecylbenzenesulfonate (hereinafter referred to as BDBS) and 3mmol of tetrahydrofuran (hereinafter referred to as THF), BDBS into each polymerization bottle. The molar ratio to the initiator is 1.0, and then 10g of styrene is added, and 0.1mmol of n-butyl lithium (designed molecular weight is 100,000) is added, respectively, in a constant temperature water bath at 10℃, 30℃, 50℃, 100℃ and 120℃ The polymerization is carried out for 1 hour. After the polymerization is finished, the polymer is terminated with ethanol, and then the polymer is precipitated with ethanol, and dried in a vacuum oven at 50°C. The monomer conversion rates are 75.62%, 80.00%, 90.88%, 100%, and 100%, respectively. The sample was extracted with methyl ethyl ketone for 8 hours, and the insoluble co...

Embodiment 2

[0019] Take a 250ml polymer bottle with double-branch tubes, bake at high temperature, and replace nitrogen for more than 3 times. Use a pipette to add 100ml hexane to the polymerization flask, then add 0.12 BDBS and 2.0mmolTHF, the molar ratio of BDBS to initiator is 0.6, add 0.2mmol n-butyllithium (design molecular weight is 50000), and stir at room temperature 30 min to make the initiation system mix uniformly, then add 10 g of styrene, and polymerize in a constant temperature water bath at 0°C for 4 hours. After the polymerization is finished, it is terminated with ethanol, and then the polymer is precipitated with ethanol and dried in a vacuum oven at 50°C. The monomer conversion rate is 80.10%. The sample was extracted with methyl ethyl ketone for 8 hours, and its insoluble content was determined to be 94.29%.

Embodiment 3

[0021] Take a 250ml polymer bottle with double-branch tubes, bake at high temperature, and replace nitrogen for more than 3 times. Use a pipette to add 100ml cyclohexane to the polymerization flask, then add 0.12 BDBS and 2.0mmolTHF, the molar ratio of BDBS to initiator is 0.6, add 0.2mmol n-butyl lithium (design molecular weight is 50000), at room temperature Stir for 30 minutes to make the initiation system mix uniformly, then add 10 g of styrene, and polymerize in a constant temperature water bath at 60° C. for 4 hours. After the polymerization is finished, it is terminated with ethanol, and then the polymer is precipitated with ethanol and dried in a vacuum oven at 50°C. The monomer conversion rate is 85.72%. The sample was extracted with methyl ethyl ketone for 8 hours, and its insoluble content was determined to be 79.02%.

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Abstract

This invention relates to a anionic polymerization method of synthesizing isotactic polystyrene, belong to macromolecular compound synthetic region. It first takes organic lithium or organic lithium alive polymer of 1 - 20mmol per 100 gram as initiator, pentamethide and lewis base as additive. The mol ratio of pentamethide and initiator is 0.2 - 2.0:1 , lewis base and initiator is 0 - 60:1. Establish initiating system at organic solvent, then add styrene monomer, takes polymerization at 0 to 120 deg, obtain isotactic polystyrene or block polymer containing isotactic polystyrene. This method can realize control to polystyrene ethylene stereoregularity, and has high monomer conversion rate.

Description

Technical field [0001] The invention belongs to the field of polymer compound synthesis, and particularly relates to the field of anionic polymerization. Background technique [0002] From the perspective of stereoregularity, polystyrene has three three-dimensional structures, namely atactic polystyrene (a-PS), isotactic polystyrene (i-PS) and syndiotactic polystyrene (s-PS) . Atactic polystyrene is in a glass state, and its glass transition temperature Tg is about 100°C. Isotactic and syndiotactic polystyrene have crystallinity due to their regular structure, and their crystalline melting points are about 220°C and 270°C, respectively. [0003] The research on the synthesis of isotactic polystyrene (i-PS) was carried out earlier. As early as 1955, i-PS was synthesized under the initiation of Ziegler-Natta catalyst, but because its crystallinity is not too high, The crystallization rate is also relatively slow, so no suitable industrial application can be found, and there are no ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F112/08C08F4/48
Inventor 韩丙勇史丰田鲁建民杨万泰
Owner BEIJING UNIV OF CHEM TECH