CN109776790B

CN109776790B - Method for synthesizing polyphenyl ether by oxidative coupling polymerization

Info

Publication number: CN109776790B
Application number: CN201711101824.8A
Authority: CN
Inventors: 黄家辉; 王奂
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2017-11-10
Filing date: 2017-11-10
Publication date: 2021-04-20
Anticipated expiration: 2037-11-10
Also published as: CN109776790A

Abstract

The invention discloses a continuous production method for preparing polyphenyl ether by oxidative coupling polymerization of phenol monomers, which comprises the steps of carrying out oxidative coupling polymerization reaction on the phenol monomers by a fixed bed reactor filled with a catalyst in the presence of a certain proportion of the phenol monomers, an organic solvent and water oxygen-containing gas; the catalyst is an imidazole-based crosslinked polymer loaded copper nanoparticle compound. The method has the advantages of simple and easy process, low cost and capability of realizing continuous large-scale production, greatly reduces the residual quantity of catalyst metal in the product, keeps the excellent electrical property of the polyphenyl ether, has wide development space and great market application value, and better meets the requirement of sustainable development.

Description

Method for synthesizing polyphenyl ether by oxidative coupling polymerization

Technical Field

The invention relates to the technical field of polymer chemical industry, in particular to a method for preparing polyphenyl ether by oxidative coupling polymerization of phenol monomers in an oil/water two-phase medium in a fixed bed reactor.

Background

Poly (2, 6-dimethylphenylene ether) (PPE) is one of five engineering plastics, has good mechanical property and electrical property, such as high glass transition temperature, good dimensional stability, heat resistance, acid and alkali corrosion resistance, low dielectric constant, low dissipation factor and the like, and is widely applied to the fields of electronics and electricity, automobile industry, mechanical manufacturing and the like. U.S. Pat. Nos. 3,306,874, 3,306,875, 3,257,357, 3,257,358 and the like disclose homogeneous processes for the production of polyphenylene ethers by oxidative coupling polymerization of phenolic monomers in organic solvents catalyzed by monovalent copper complexes. The method adopts an intermittent kettle type production process, a large amount of heat is released in the reaction process, an explosion-proof reactor is needed, a large amount of copper ions are contained in a crude product due to a homogeneous system, so that the electrical performance of the crude product is influenced, and meanwhile, the cost is increased and the environment is polluted because the catalyst and the ligand cannot be recovered.

The adoption of a heterogeneous system for continuously producing the polyphenyl ether can greatly reduce the production cost of the polyphenyl ether and simultaneously reduce the residual quantity of metal ions in the product while improving the safety of the reaction process and the quality stability of the product, thereby improving the electrical property of the product.

Aiming at the characteristics of homogeneous oxidative coupling polymerization reaction of phenol monomers in an oil-water two-phase medium, the copper nanoparticle catalyst loaded by the synthesized imidazolyl crosslinked polymer is designed and filled in a fixed bed, so that continuous production of polyphenylene oxide is realized, the reaction has higher efficiency and selectivity, the product quality is stable, and the residual amount of the catalyst in the product is small.

Disclosure of Invention

The invention provides a continuous production method for preparing polyphenyl ether by oxidative coupling polymerization of phenol monomers.

In order to achieve the above object, the method comprises a method of carrying out oxidative coupling polymerization of a phenol monomer, an organic solvent and water in the presence of a molecular oxygen-containing gas through a fixed bed reactor filled with a catalyst;

the catalyst is an imidazole-based crosslinked polymer loaded copper nanoparticle compound

The method for synthesizing polyphenylene oxide through oxidative coupling polymerization is characterized in that the mass ratio of raw materials in the oxidative coupling polymerization reaction is as follows:

a phenol monomer 1;

3-40% of an organic solvent;

0.1-4% of water;

in the presence of molecular oxygen, the reaction temperature is 10-60 ℃, and preferably 20-50 ℃; the reaction pressure is normal pressure to 1.0MPa, preferably normal pressure to 0.4MPa, the gas space velocity is 10mL/min to 1L/min, preferably 100mL/min to 500mL/min, and the liquid flow rate is 10mL/min to 500mL/min, preferably 50 mL/min to 300 mL/min.

The phenol monomer is a compound shown in a structural formula (I):

formula (I)

In the formula (I), R₁And R₂Are respectively C₁～C₄Alkyl of (C)₂～C₄Alkenyl or phenyl of R₁And R₂The same or different.

The copper nanoparticle catalyst loaded on the imidazolyl crosslinked polymer is a compound obtained by coordinating the imidazolyl crosslinked polymer with a divalent copper compound solution and then reducing the coordination compound with sodium borohydride.

The catalyst is an imidazole-based crosslinked polymer loaded copper nanoparticle compound.

The phenol monomer is a compound shown in a structural formula (I):

formula (I)

In the formula (I), R₁And R₂Are respectively C₁～C₄Alkyl, alkenyl or phenyl of R₁And R₂The same or different;

The imidazolyl crosslinked polymer is a crosslinked copolymer of a divinylbenzene monomer, a vinyl imidazole monomer and one or more oil-soluble vinyl monomers;

the molar ratio of the divinyl benzene monomer to the vinyl imidazole monomer to one or more other oil-soluble vinyl monomers in the polymer is 1-10: 1: 0.001-1, preferably 1-5: 1: 0.01-0.3;

wherein the divinyl benzene monomer is a compound shown in a structural formula (II), and the vinyl imidazole monomer is a compound shown in a structural formula (III):

formula (II);

in the formula (II), R₃Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₄Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₅Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₆Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₇Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₃、R₄、R₅、R₆And R₇The same or different, and at least one is a vinyl group;

formula (III);

in the formula (III), R₈Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₉Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₁₀Is hydrogen, alkyl with 1 to 4 carbon atoms or BAlkenyl radical, R₁₁Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₈、R₉、R₁₀And R₁₁The same or different, and at least one is a vinyl group;

the oil-soluble vinyl monomer is a styrene monomer, a methyl acrylate monomer or a methyl methacrylate monomer.

The cupric compound solution is methanol solution of at least one of cupric chloride, cupric bromide, cupric nitrate and cupric sulfate.

The feeding mass ratio of the divalent copper compound to the polymer is 0.5-40: 100, preferably 5-20: 100; the molar ratio of the sodium borohydride to the bivalent copper compound is 0.275-20: 1.

According to the mass ratio of the divalent compound to the imidazolyl crosslinked polymer, the imidazolyl crosslinked polymer is immersed into a methanol solution containing a divalent copper compound and is stirred vigorously for 8-24 hours, a solid obtained by a coordination reaction between copper ions and nitrogen in the imidazolyl crosslinked polymer is immersed into the methanol solution prepared according to the molar ratio of the divalent copper compound to sodium borohydride, and is stirred vigorously for 6-24 hours, so that the imidazolyl crosslinked polymer supported copper nanoparticle catalyst is prepared.

The copper nanoparticles account for 0.5-20% by mass of the catalyst, and preferably account for 3-12% by mass of the catalyst; the size range is 0.5 to 10nm, preferably 0.5 to 5 nm.

The organic solvent is one of toluene, chloroform, dichloromethane and nitrobenzene.

The raw materials and reagents of the invention can adopt products sold in the market.

Compared with the prior art, the invention has the following remarkable progress:

the invention has the advantages that: the method has the advantages of simple and easy process, low cost and capability of realizing continuous large-scale production, greatly reduces the residual quantity of catalyst metal in the product, and keeps the excellent electrical properties of the polyphenyl ether. The catalyst combines the characteristics of the copper nanoparticles and the imidazolyl crosslinked polymer; the imidazolyl crosslinked polymer has a spatial network structure, divalent copper ions can be fixed in a network while being reduced after being complexed with nitrogen in the imidazolyl crosslinked polymer, and the loading amount of copper in the catalyst can be adjusted by adjusting the content of the imidazolyl, the crosslinking degree and the using amount of copper; the imidazolyl is an alkaline ligand required by the oxidative coupling reaction of the phenol monomer, the reduced copper nanoparticles still keep weak complexation with the nitrogen in the imidazolyl under the complexation of the nitrogen in the imidazolyl and divalent copper ions in the preparation process, and meanwhile, the cross-linked polymer locally increases the concentration of the catalyst and the ligand, so that the oxidation reaction rate and the catalyst efficiency are effectively improved; the synthetic method has wide development space and great market application value, and meets the requirement of sustainable development.

Detailed Description

Example 1 preparation of nitrogen-containing crosslinked Polymer Supported copper nanoparticle catalyst

In a three-necked flask, Divinylbenzene (DVB) (2.0g, 15mmol), Vinylimidazole (VI) (0.483g, 5mmol), methyl methacrylate (0.5g, 5mmol), azobisisobutyronitrile (0.07g), and ethyl acetate (30ml) were added under nitrogen. The reaction was carried out at 100 ℃ for 24 hours without stirring, and after the completion of the reaction, the solvent was dried to obtain 2.1g of a white powder which was a copolymer of divinylbenzene and vinylimidazole (PDVB-MMA-VI).

200mg of the above white powder was immersed in CuCl₂And (10mg) in methanol solution (10mL), stirring vigorously for 16h, centrifuging, washing with methanol, putting into methanol solution (10mL) of sodium borohydride (10mg), stirring vigorously for 16h, centrifuging, and washing with methanol to obtain the nitrogen-containing crosslinked polymer supported copper nanoparticle catalyst, wherein the copper mass loading is 1.34%.

Examples 2 to 7

The method of example 1 was used to prepare a nitrogen-containing crosslinked polymer supported copper nanoparticle catalyst, except that the molar ratio of DVB to VI and the amount of divalent copper compound used in the synthesis of PDVB-MMA-VI were varied, as shown in Table 1:

examples 8 to 10

A nitrogen-containing crosslinked polymer-supported copper nanoparticle catalyst was prepared by the method of example 1, except for changing the kind and amount of the divalent copper compound, as shown in table 2:

EXAMPLE 11 oxidative coupling polymerization of phenol monomers in a fixed bed

100mg of the catalyst of example 1 was charged into a stainless steel reaction tube having a diameter of 13mm, and the reaction solution was a mixed solution of 2, 6-Dimethylphenol (DMP), water and toluene (wherein the mass ratio of DMP: water: toluene was 1:1:10), the flow rate was 10mL/min, and the oxygen flow rate was 100 mL/min. After the reaction tube was heated to 40 ℃, the reaction solution was started to flow in. As the reaction proceeded, the DMP conversion tended to be stable, the solvent portion was added dropwise to excess methanol and centrifuged to give the product, the yield of polyphenylene ether (PPE) was about 88.9%, the content of by-product (DPQ) was 0.5%, and the PPE weight-average molecular weight M was_n60000 and a molecular weight distribution DP of 2.2.

Examples 12 to 17

PPE were prepared according to the procedure of example 11, except that the catalysts prepared in examples 2-7 were used, respectively, and the reaction results are shown in Table 3:

examples 18 to 20

PPE were prepared according to the procedure of example 11, except that the catalysts prepared in examples 8-10 were used, respectively, and the reaction results are shown in Table 4:

example 21

An alcohol was selectively oxidized in aqueous medium according to the method of example 11, except that the ratio of DMP: water: the mass ratio of toluene was 2:1:10, the DMP conversion tended to stabilize at about 87.8%, the yield of polyphenylene ether (PPE) was about 85%, the content of by-products (DPQ) was 0.6%, and the weight-average molecular weight M of PPE was_n58000, molecular weight distribution DP 2.0.

TABLE 1

Example number	Copper chloride dosage (mg)	Molar ratio of DVB to VI in PDVB-VI	Copper loading (%)
				2	20	3	2.64
3	40	3	5.01
				4	10	10	1.02
5	20	10	1.95
				6	10	1	1.57
7	20	1	3.18

TABLE 2

Example number	Copper compound	Copper Compound dosage (mg)	Copper loading (%)
				8	Copper nitrate	20	2.71
9	Copper sulfate	40	4.78
				10	Copper bromide	30	3.11

TABLE 3

Example number	Sources of catalyst	M_w	DP	Yield (%)	DPQ(％)
						12	Example 2	59000	2.3	88.1	0.8
13	Example 3	55000	1.8	91.2	0.7
						14	Example 4	64000	2.5	92.0	0.2
15	Example 5	57000	2.3	87.9	0.5
						16	Example 6	55000	1.8	89.3	0.3
17	Example 7	58000	1.7	91.7	0.4

TABLE 4

Example number	Sources of catalyst	M_w	DP	Yield (%)	DPQ(％)
						18	Example 8	57000	2.3	88.1	0.6
19	Example 9	50000	1.8	91.2	0.5
						20	Example 10	65000	2.5	92.0	0.4

Claims

1. A method for synthesizing polyphenyl ether by oxidative coupling polymerization is characterized in that: a method for carrying out oxidative coupling polymerization reaction of phenol monomers by passing the phenol monomers, an organic solvent and water through a fixed bed reactor filled with a catalyst in the presence of molecular oxygen-containing gas;

2. The method for synthesizing polyphenylene ether by oxidative coupling polymerization as claimed in claim 1, wherein the mass ratio of the raw materials in the oxidative coupling polymerization reaction is as follows:

a phenol monomer 1;

3-40% of an organic solvent;

0.1-4% of water;

in the presence of molecular oxygen, the reaction temperature is 10-60 ℃, the reaction pressure is normal pressure-1.0 MPa, the gas airspeed is 10 mL/min-1L/min, and the liquid flow rate is 10-500 mL/min.

3. The method for synthesizing polyphenylene ether by oxidative coupling polymerization according to claim 1, wherein the phenol monomer is a compound represented by the structural formula (I):

formula (I)

In the formula (I), R₁And R₂Are respectively C₁~C₄Alkyl of (C)₂~C₄Alkenyl or phenyl of R₁And R₂The same or different.

4. The method according to claim 1, wherein the copper nanoparticle-supported imidazolyl cross-linked polymer catalyst is a complex obtained by coordinating imidazolyl cross-linked polymer with a solution of a divalent copper compound and then reducing the coordination compound with sodium borohydride.

5. The method according to claim 1, wherein said imidazolyl cross-linked polymer is a cross-linked copolymer of a divinylbenzene-type monomer with a vinyl imidazole-type monomer and other one or more oil-soluble vinyl monomers;

the molar ratio of the divinyl benzene monomer to the vinyl imidazole monomer to one or more other oil-soluble vinyl monomers in the polymer is 1-10: 1: 0.001-1;

formula (II);

in the formula (II), R₃Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₄Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₅Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₆Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₇Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₃、R₄、R₅、R₆And R₇The same or different, and the same or different,and at least one is vinyl;

formula (III);

in the formula (III), R₈Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₉Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₁₀Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₁₁Is hydrogen, alkyl or vinyl with 1 to 4 carbon atoms, R₈、R₉、R₁₀And R₁₁The same or different, and at least one is a vinyl group;

6. The method of claim 4, wherein the solution of the cupric compound is a methanolic solution of at least one of cupric chloride, cupric bromide, cupric nitrate, and cupric sulfate.

7. The method according to claim 4, wherein the feeding mass ratio of the divalent copper compound to the imidazolyl crosslinked polymer is 0.5-40: 100, and the molar ratio of the sodium borohydride to the divalent copper compound is 0.275-20: 1.

8. The method of claim 7, comprising the steps of: according to the mass ratio of the divalent copper compound to the imidazolyl group cross-linked polymer, immersing the imidazolyl group cross-linked polymer into a methanol solution containing the divalent copper compound, and violently stirring for 8-24 hours, immersing a solid obtained by the coordination reaction of copper ions and nitrogen in the imidazolyl group cross-linked polymer into the methanol solution prepared according to the molar ratio of the divalent copper compound to sodium borohydride, and violently stirring for 6-24 hours to obtain the imidazolyl group cross-linked polymer supported copper nanoparticle catalyst.

9. The method according to claim 4 or 8, wherein the copper nanoparticles are present in the catalyst in a mass fraction of 0.5 to 20% and have a size in the range of 0.5 to 10 nm.

10. The method of claim 4 or 8, wherein the organic solvent is one of toluene, chloroform, dichloromethane, nitrobenzene.