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Process for semi-continuous preparation of syndiotactic polystyrene particles

A technology of polystyrene particles and polystyrene, applied in the field of semi-continuous preparation of syndiotactic polystyrene particles, to achieve high conversion rate, high bulk density, and prevent gelation

Inactive Publication Date: 2006-06-07
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The research on the polymerization process is far less in-depth than that of the special reactor. In the CN1253956A and CN1329096A syndiotactic polystyrene bulk polymerization, the aging technology and the process of adding catalyst in batches point out that the reaction process is stable and the reactor is not easy to agglomerate , the product is in the form of powder, but it does not involve important indicators such as the shape and bulk density of the powder

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] 5 liter stainless steel vertical reactor with special-shaped twin-screw stirring paddles, put 0.2 kg of syndiotactic polystyrene seeds in advance, dry at high temperature for a certain period of time and replace it with high-purity nitrogen for micro-positive pressure protection, and wait until the temperature of the kettle drops to At 60°C, first add 0.5 liters of hexane, 0.3 liters of heptane, 0.2 liters of chlorobenzene and 0.2 liters of styrene monomer, then add 50 milliliters of toluene solution of 72 mmoles of methyl aluminoxane and 72 mmoles of triisobutyl 50 ml of toluene solution of base aluminum, and keep the temperature of the system constant at 60°C required for polymerization, age for 15 minutes, and then add 0.24 mmol of Cp*Ti(OCH 3 ) 3 50 milliliters of toluene solution was injected into the reactor to start polymerization, the stirring speed was 300 rpm, and 1.8 liters of styrene monomer was added dropwise at a speed of 0.6 liters / hour after 15 minutes, ...

Embodiment 2

[0026] 5 liter stainless steel vertical reactor with special-shaped twin-screw stirring paddles, put 0.2 kg of syndiotactic polystyrene seeds in advance, dry at high temperature for a certain period of time and replace it with high-purity nitrogen for micro-positive pressure protection, and wait until the temperature of the kettle drops to At 60°C, add 0.5 liters of hexane, 0.5 liters of heptane and 0.2 liters of styrene monomer, and keep the temperature of the system constant at 60°C required for polymerization. Solution and 50 milliliters of toluene solutions of 72 millimoles of triisobutylaluminum were added in the reactor respectively, aged for 15 minutes, and then 0.24 millimoles of Cp*Ti(OCH 3 ) 3 50 milliliters of toluene solution was injected into the reactor to start polymerization, the stirring speed was 300 rpm, and 1.8 liters of styrene monomer was added dropwise at a speed of 0.6 liters / hour after 15 minutes, and there was no sudden increase in internal temperatur...

Embodiment 3

[0028] 5 liter stainless steel vertical reactor with special-shaped twin-screw stirring paddles, put 0.2 kg of syndiotactic polystyrene seeds in advance, dry at high temperature for a certain period of time and replace it with high-purity nitrogen for micro-positive pressure protection, and wait until the temperature of the kettle drops to At 60°C, add 0.5 liters of hexane, 0.5 liters of toluene and 0.2 liters of styrene monomer, and keep the temperature of the system constant at 60°C required for polymerization. and 50 milliliters of toluene solutions of 72 mmoles of triisobutylaluminum were added to the reaction kettle, aged for 15 minutes, and then 0.24 mmoles of Cp*Ti(OCH 3 ) 3 50 milliliters of toluene solution was injected into the reactor to start polymerization, the stirring speed was 300 rpm, and 1.8 liters of styrene monomer was added dropwise at a speed of 0.6 liters / hour after 15 minutes, and there was no sudden increase in internal temperature or stirring torque a...

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Abstract

The invention discloses a semi-continuous preparation method of syndiotactic polystyrene particles. In the method, styrene is used as a monomer, a titanocene metal compound is used as a main catalyst, and alkylaluminoxane and triisobutylaluminum are used as cocatalysts. The seed semi-continuous polymerization is carried out in a composite inert medium at normal pressure and a temperature of 50-80°C. The seeds are syndiotactic polystyrene particles with better particle shape, which can be synthesized in situ or heat-treated the pre-obtained syndiotactic polystyrene particles to obtain seeds with better shape. The invention has the advantages of non-stick caking, low unit power consumption of the reactor, stable reaction and easy operation, high styrene conversion rate, and the bulk density of the final product is not less than 0.45g / cm 3 It is convenient for industrial production and is suitable for all kinds of vertical or horizontal stirring polymerization kettles.

Description

technical field [0001] The invention relates to a semi-continuous preparation method of syndiotactic polystyrene particles. Background technique [0002] Styrene homopolymer can be divided into three types: atactic, isotactic and syndiotactic according to its stereoregularity. Atactic polystyrene is an amorphous polymer, which has excellent electrical insulation, transparency and chemical corrosion resistance, and has certain mechanical strength, but its biggest disadvantage is that it is relatively brittle, low in impact resistance, and poor in heat resistance. . Isotactic polystyrene is a crystalline polymer with a melting point of about 240°C, but it is difficult to obtain industrial applications because of its slow crystallization rate. Syndiotactic polystyrene is also a crystalline polymer with a melting point as high as 270°C, which is similar to engineering plastic nylon-66. It is a rare non-polar engineering plastic with the characteristic...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F112/08C08F4/642C08F2/06
Inventor 曹堃李伯耿
Owner ZHEJIANG UNIV