阅读说明：本技术 一种氯化铝负载MOFs催化剂及其在高活性聚异丁烯生产工艺中的应用 (Aluminum chloride loaded MOFs catalyst and application thereof in production process of high-activity polyisobutylene ) 是由 田晖 孙大海 房德仁 魏海生 陈小平 任万忠 于 2020-07-09 设计创作，主要内容包括：本发明公开了一种氯化铝负载MOFs催化剂,其为负载AlCl<Sub>3</Sub>的有机金属框架物材料,由AlCl<Sub>3</Sub>与有机配体通过配位键形成,命名为AlCl<Sub>3</Sub>/MOF复合催化剂。其所述的有机配体为1,4苯二甲酸。本发明还公开了该催化剂在高活性聚异丁烯生产工艺中的应用。本发明获得的催化剂材料的孔道规则有序,将AlCl<Sub>3</Sub>复合引发剂均匀负载其中,有利于与反应体系里异丁烯单体均匀接触,提高聚合产物分子量的可控性。将新型复合材料应用到异丁烯聚合反应工艺中,有利于提高产物收率到85％以上,降低生产成本约30％,节约设备投资约20％。(The invention discloses an aluminum chloride loaded MOFs catalyst, which is loaded with AlCl 3 The organic metal framework material is prepared from AlCl 3 Formed by coordination bonds with organic ligands and named AlCl 3 a/MOF composite catalyst. The organic ligand is 1,4 phthalic acid. The invention also discloses the application of the catalyst in the production process of high-activity polyisobutylene. The catalyst material obtained by the invention has ordered pore channels, and AlCl is added 3 The composite initiator is uniformly loaded in the reaction system, so that the reaction system is in favor of uniform contact with isobutene monomers in the reaction system, and the controllability of the molecular weight of a polymerization product is improved. The novel composite material is applied to the isobutylene polymerization reaction process, which is favorable for improving the product yield to over 85 percent, reducing the production cost by about 30 percent and saving the equipment investment by about 2 percent0％。)

1. An aluminum chloride loaded MOFs catalyst is characterized in that the catalyst is loaded with AlCl₃The organometallic framework material of (1).

2. The MOFs catalyst supported on aluminum chloride according to claim 1, wherein the organic ligand is 1,4 phthalic acid.

3. The MOFs catalyst supported on aluminum chloride according to claim 2, characterized in that the preparation process comprises the following steps:

(1) mixing AlCl₃Dissolving in benzoic acid, ethyl benzoate and isopropyl ether to obtain a mixed solution A;

(2) dissolving 1,4 phthalic acid in N, N-dimethylformamide to obtain a mixed solution B;

(3) uniformly mixing the mixed solution A and the mixed solution B, adding pyridine into the mixed solution, and uniformly mixing;

(4) carrying out closed reaction at the temperature of 140-160 ℃ on the mixed solution obtained in the step (3) for 8-18h, cooling to the temperature below 40 ℃, and separating to obtain a solid;

(5) washing the solid obtained in the step (4) with N, N-dimethylformamide, and drying to obtain AlCl₃a/MOF composite catalyst.

4. The MOFs catalyst loaded with aluminum chloride according to claim 3, wherein in step (1), AlCl is added₃: benzoic acid: ethyl benzoate: the molar ratio of isopropyl ether is 1: (5-7): (0.2-0.3): (0.2-0.4).

5. The aluminum chloride supported MOFs catalyst according to claim 3, wherein AlCl₃The molar ratio of 1,4 phthalic acid to 1: (0.6-1).

6. The aluminum chloride supported MOFs catalyst of claim 3, wherein the molar ratio of 1,4 phthalic acid to pyridine is 1: (0.8-1.2).

7. The MOFs catalyst loaded with aluminum chloride according to claim 3, wherein in the step (3), after the pyridine is added, the mixture is subjected to ultrasonic oscillation for 5-15 min.

8. The MOFs catalyst loaded with aluminum chloride according to claim 3, wherein said drying in step (5) is carried out at 55-75 ℃ for 8-15h under vacuum.

9. Use of the aluminum chloride supported MOFs catalyst according to any one of claims 1 to 8 in a process for the production of highly active polyisobutenes.

10. Use according to claim 9, wherein AlCl in the aluminium chloride supported MOFs catalyst is used in a process for the production of highly active polyisobutenes₃The mass ratio of the raw material isobutene to the raw material isobutene is 1: (80-150).

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to an aluminum chloride loaded MOFs catalyst and application thereof in a production process of high-activity polyisobutylene.

Background

Organometallic framework materials (MOFs for short) are a new class of porous materials with stable structures, also known as coordination polymers. The porous material is a new porous material superior to the traditional material in recent years, has the characteristics of good thermal stability and chemical stability, regular and ordered pore channels, modified skeleton structure and pore channel size according to target requirements and the like, and has wide application prospect. For example, the Zhou theme group at the university of texas, usa, developed popular PNC series materials using carboxylic MOF materials, which have two channel structures of triangle and hexagon, with diameters of 1.3nm and 3.2nm, respectively, have excellent chemical stability, and can still maintain their channel-type framework structures in boiling water and high-concentration hydrochloric acid solution. In addition, the porphyrin ligand center can chelate metal ions such as Fe, Co, Ni, Cu and the like, and endows the metal ions with excellent catalytic performance, so that the porphyrin ligand center has wide development prospect in the catalytic field. The Chen Xiaoming academy subject group of the university of Zhongshan applies a nitrogen-containing ligand to the synthesis of MOF materials, and zeolite-like ZIF series materials constructed by imidazole ligands are reported on Ange. chem. int. Ed and PNAS in sequence, wherein the most famous ZIF-8 constructed by Zn2+ and dimethyl imidazole has ultrahigh thermal stability and chemical stability, a simple preparation method and relatively low price. The method is widely applied to the fields of adsorption, separation, catalysis and the like.

The high-activity polyisobutylene (HRPIB) is a Polyisobutylene (PIB) product with the molecular weight of 500-5000 and the alpha-olefin content of more than 60%. Is tasteless and nontoxic, and has good heat resistance, oxygen resistance, chemical resistance, ultraviolet resistance, acid resistance, alkali resistance and other properties. Meanwhile, the volume resistivity is high, and the expansion coefficient is small. Can penetrate into almost all application fields of low molecular weight polyisobutylene (LPIB), is widely applied to lubricating oil, fuel dispersant and detergent, and can also be used for preparing transmission oil, hydraulic fluid, insulating oil, metal processing fluid and the like.

AlCl₃Is a common Lewis acid initiator for isobutylene cationic polymerization and is prepared from AlCl₃As an initiatorThe polyisobutene product obtained by polymerization has the advantages of simple product post-treatment, no halogen residue, greenness, no pollution and the like. The cationic polymerization of isobutene features fast initiation of monomer, fast active chain growth, easy chain transfer during the growth, less spontaneous termination of active chain reaction and need of artificial addition of terminator. Therefore, when a conventional stirred tank reactor is used to produce highly reactive polyisobutene, the reaction system is not uniformly mixed just before the reaction is started, so that local isobutene reacts violently with a region with high initiator concentration, and the heat of polymerization cannot be dissipated or even "boiling" occurs. The yield of the obtained product is low, and the molecular weight dispersity is particularly poor.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides an aluminum chloride supported MOF material catalyst prepared by carrying out AlCl on an AlCl-supported MOF material₃The catalyst is loaded in the MOF material, so that the problems of complex traditional process, high energy consumption, poor molecular weight distribution of products and the like are solved, and the occurrence of chain transfer of polymerization products and the branching degree of molecular chains are reduced.

The specific technical scheme is as follows:

one of the purposes of the invention is to provide an aluminum chloride supported MOFs catalyst which is loaded with AlCl₃The organometallic framework material of from AlCl₃Formed by coordination bonds with organic ligands and named AlCl₃a/MOF composite catalyst.

Further, the organic ligand is 1,4 phthalic acid (H)₂BDC)。

MOF materials are a class of crystalline porous materials formed by coordination bonds of metal ions or metal clusters and organic ligands. The material has numerous types and different performances, and can be synthesized into a material with a target structure according to specific application and requirements. Even if the same MOF material is adopted, different synthesis conditions or activation methods are adopted, so that the obtained samples have larger differences in crystallinity, pore structures, morphologies and crystal sizes, and the obtained specific surface areas and pore volumes are different. Because of AlCl₃Has good catalytic performance on cationic polymerization, so the application is wide, but the polymerization processThe existing catalytic system can not distribute the whole reaction system in time, so that the macromolecular chain length of the polymerization product is short and not uniform enough, and the molecular weight distribution is poor. The advantages of the MOF material can effectively make up for the traditional AlCl₃Insufficient catalytic effect.

Therefore, an AlCl is designed and researched₃The MOF novel composite material is prepared by adding an MOF material into a solution containing a metal precursor, fully and uniformly mixing, spontaneously permeating liquid (precursor containing metal Al element) into the inner pore channels of MOF by utilizing the capillary force of the pore channels of MOF, collecting solids by centrifuging, filtering and other modes, and finally oxidizing the metal precursor into AlCl by chemical treatment₃，AlCl₃The degree of loading is determined by the pore structure and size of the MOF support. Meanwhile, the structure of the MOF material can be regulated and controlled on a molecular scale layer due to high designability and tailorability, so that the optimal catalytic type beneficial to experimental polymerization can be regulated and designed.

Still further, the AlCl₃The preparation method of the MOFs-loaded catalyst comprises the following steps:

(1) mixing AlCl₃Dissolving in benzoic acid, ethyl benzoate and isopropyl ether to obtain a mixed solution A;

(2) dissolving 1,4 phthalic acid in N, N-dimethylformamide to obtain a mixed solution B;

(3) uniformly mixing the mixed solution A and the mixed solution B, adding pyridine into the mixed solution, and uniformly mixing;

(4) carrying out closed reaction at the temperature of 140-160 ℃ on the mixed solution obtained in the step (3) for 8-18h, cooling to the temperature below 40 ℃, and separating to obtain a solid;

(5) washing the solid obtained in the step (4) with N, N-dimethylformamide, and drying to obtain AlCl₃a/MOF composite catalyst.

Wherein, in the step (1) of the preparation method, AlCl is adopted₃: benzoic acid: ethyl benzoate: the molar ratio of isopropyl ether is preferably 1: (5-7): (0.2-0.3): (0.2-0.4).

Wherein, in the preparation method, AlCl is adopted₃The molar ratio to 1, 4-benzenedicarboxylic acid is preferably 1: (0.6-1).

In the preparation method, the molar ratio of the 1,4 phthalic acid to the pyridine is 1: (0.8-1.2).

Wherein, in the step (3) of the preparation method, after the pyridine is added, the system can be promoted to be uniformly mixed by ultrasonic oscillation, and the ultrasonic oscillation is preferably carried out for 5-15 min.

Among them, in the step (4) of the above production method, it is preferable to stir during the reaction; the separation is preferably a centrifugal separation.

Wherein, in the step (5) of the preparation method, the drying is vacuum drying for 8-15h at 55-75 ℃.

Another object of the present invention is to provide the above AlCl₃Application of the/MOF composite catalyst in a production process of high-activity polyisobutene.

Preferably, AlCl₃AlCl in supported MOFs catalyst₃The mass ratio to the raw material isobutylene is preferably 1: (80-150).

The operation of the reaction temperature of the catalyst obtained by the invention for initiating the cationic polymerization of isobutene is required to be realized in the range of-40 to-20 ℃.

The operation of the reaction temperature, which is not described in the present invention, can be carried out within the range of 10 to 30 ℃.

Directly uses AlCl in the prior method₃As compared with initiator, AlCl obtained by the invention₃The MOF composite catalyst has the advantages that the initiator is uniformly distributed in the whole material, so that the generated polymerization heat is relatively uniform, the local enrichment of the initiator is avoided, and the problem that the polymerization heat cannot be dispersed and even boils in the reaction is solved. Can obtain the high-activity polyisobutene product with high final yield and good molecular weight dispersity.

AlCl of the invention₃The MOF composite catalyst is matched with the device disclosed in the invention patent application 'a production device and a production process of high-activity polyisobutylene' of which the application date is 2020, 4 and 24 days and the application number is 202010332789.6 of the applicant of the invention, so that the further beneficial effect is obtained, and the yield and the dispersity of the molecular weight can be further obviously improved.

The above-mentioned invention patent application discloses a production apparatus for highly reactive polyisobutyleneThe precooler may be charged with a suitable solvent for cryogenic treatment, followed by the isobutene feed and brought to the appropriate isobutene monomer concentration. When the reaction temperature is controlled to be proper through the precooler, the mixture is sprayed to the modified kettle type reactor through the pipeline liquid distributor to carry out the polymerization reaction. The diameter of the inner wall of the reactor was 30cm and the height was 1 m. It improves the traditional kettle type reactor and uses AlCl₃The MOF novel composite material is uniformly filled in the kettle body, and proper AlCl is controlled₃And the corresponding amount of co-initiator is uniformly loaded in the MOF material, and a refrigeration tube is inserted in AlCl₃Between the novel composite materials of the MOF.

When the solution containing isobutene is sprayed directly from the top of the tower, it can contact with initiating system in the pore size of the composite material to produce polymerization reaction, and because the initiating agent is uniformly distributed in the whole material, the generated polymerization heat is relatively uniform, and the heat can be timely taken away by refrigerating pipe in the material to keep the polymerization temperature unchanged. Therefore, the problems that when the reaction is about to start, the reaction system is not uniformly mixed, the generated initiator is locally enriched, and the polymerization heat of the reaction cannot be dispersed and even is boiled in the traditional high-activity polyisobutylene production process are further solved. The yield and the molecular weight dispersity can be further remarkably improved on the basis of the device.

The invention has the following beneficial effects:

(1) the MOF material has ordered pore channels, and AlCl is formed₃The composite initiator is uniformly loaded in the reaction system, so that the reaction system is in favor of uniform contact with isobutene monomers in the reaction system, and the controllability of the molecular weight of a polymerization product is improved;

(2) molecular chains with branched chains in the polymerization product can be blocked through the aperture of the MOF material, so that a uniform linear molecular chain polymerization product is obtained, and a product with excellent quality and controllable molecular weight is obtained;

(3) the novel composite material is applied to the isobutylene polymerization reaction process, which is favorable for improving the product yield to over 85 percent, reducing the production cost by about 30 percent and saving the equipment investment by about 20 percent.

Detailed Description

The principles and features of this invention are described below in conjunction with examples, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.