Method for preparing low cis-polybutadiene by stepwise excitation

A technology for butadiene and a polymerization method, applied in 1 field, can solve the problems of difficult control, complicated polymerization operation, difficult reaction control, etc., to increase molecular weight distribution, improve gloss, and reduce the amount of initiator and coupling agent. Effect

Active Publication Date: 2005-07-20
中国石油化工股份有限公司北京燕山分公司研究院
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the polymerization reaction process of this method varies greatly with the process conditions, and the reaction is not easy to control. It is difficult to achieve the same structure and performance of the polymer in each kettle under the condition of batch polymerization.
[0008] In practice, for the batch polymerization process, no matter whether the initiator is continuously added or the multifunctional initiator is used, the operation of the polymerization reaction is very complicated, and the control is difficult, which is not conducive to the final industrial production of the product.

Method used

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  • Method for preparing low cis-polybutadiene by stepwise excitation
  • Method for preparing low cis-polybutadiene by stepwise excitation

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Experimental program
Comparison scheme
Effect test

Embodiment 1A

[0040] The raffinated oil is soaked with activated molecular sieves before use, so that the water content in the solvent is lower than 5ppm, deoxidized with high-purity nitrogen, and left standing for later use.

[0041] Before n-butyllithium is used, it is titrated by a double titration method, and the concentration is calibrated, and the impurity content is controlled below 5%.

[0042] Tetrahydrofuran is soaked with previously activated molecular sieves, diluted with a polymerization solvent, and deoxidized with high-purity nitrogen.

[0043] Batch polymerization was carried out in a 10-liter polymerization tank. Firstly, 4200 g of refined raffinate, 572 g of butadiene monomer and 2.36 mmol of tetrahydrofuran were sequentially added into the tank with high-purity nitrogen. When preheating to 50°C, the number average molecular weight is 660,000 for the first initiation at 0.1 MPa, and 0.87 mmol of n-butyllithium is added to initiate polymerization. When the conversion rate r...

Embodiment 1B

[0045] Cyclohexane was used as the solvent, dioxane was used as the polar regulator, and it was added according to DOX / RuLi=1.5:1; the number average molecular weight was designed to be 660,000 for the first initiation, and 0.87 mmoles of n-butyllithium was added to initiate polymerization, and the conversion rate reached 23 % by adding the secondary initiator in a mol ratio of 4: 1 with the initial initiation amount, other conditions and operations are the same as in Example 1A, and the analysis results are as shown in Table 1.

Embodiment 1C

[0047] The solvent is hexane, the polarity regulator is trichlorobenzenebicyclo[2,2,2]octane, added according to DSBCO / RuLi=0.3:1, the number average molecular weight of the first initiation design is 570000, and 1.05 mmoles of n-butyl Lithium initiates polymerization, and when conversion ratio reaches 23%, add secondary initiator with the molar ratio of 3.3: 1 with the initial initiation amount, other conditions and operation are with embodiment 1A, and analysis result is as shown in table 1.

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Abstract

The 1, 3-butadiene polymerizing process includes two-step initiated polymerization inside intermittent polymerizing system of saturated hydrocarbon solvent containing polar regulator and with alkyl lithium as initiator to produce homopolymer with different molecular weights and certain molecular weight distribution; and subsequent coupling with four functionality degree Lewis acid as coupling agent to prepare low cis-polybutadiene with wide molecular weight distribution. The present invention has the obvious features of widened molecular weight distribution of 1.6-1.8, reduced initiator and coupling agent consumption, improved 5 % styrene liquid chroma of rubber. The present invention is used in modification of polystyrene resin and can improve the degree of luster of anti-shock polystyrene.

Description

technical field [0001] This invention relates to a process for the polymerization of 1,3-butadiene. More specifically, the present invention widens the molecular weight distribution of low cis-polybutadiene rubber (LCBR) by changing the addition mode of alkyllithium (RuLi) initiator and combining polymer chain end coupling technology under batch polymerization system (M W / M N , hereinafter also referred to as HI) 1,3-butadiene polymerization method. Background technique [0002] The cis content in the microstructure of LCBR prepared with alkyllithium as an initiator is generally between 35-40%, compared with high cis polybutadiene rubber (cis content is generally greater than 96%), so it is called It is low cis polybutadiene rubber. The 1,4 structure content in LCBR is about 90%, the cis-trans structure is randomly distributed, has good low-temperature performance, and also has the characteristics of light color, transparency, gel-free and high pu...

Claims

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Application Information

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IPC IPC(8): C08F4/48C08F136/06
Inventor 吕万树于国柱鲁文平吴宁关逸英
Owner 中国石油化工股份有限公司北京燕山分公司研究院
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