Polymerization method for regulating molecular weight of polyketone

Abstract

The invention belongs to the field of polymer synthesis, and discloses a polymerization method for regulating the molecular weight of polyketone. A nickel catalyst is adopted to catalyze ethylene, CO and propylene ternary polymerization under the action of adding a chain transfer agent and a stabilizer to directly prepare a series of ternary polyketone macromolecules with different molecular weights and adjustable melting points, the synthesis route is simple and convenient to operate, the reaction conditions are relatively mild, the molecular weight range of the obtained polyketone is relatively wide, and the production cost is low. The method is suitable for preparing multi-purpose and multifunctional polyketone high polymer materials through multiple processing ways. The molecular weight of the obtained polyketone is more than 80,000 and less than 200,000, and the polyketone can be processed into engineering plastics in injection molding, extrusion molding and other modes; the molecular weight of the obtained polyketone is as high as more than 9 million, and the application prospect of the polyketone for solution spinning into a polyketone super-strong fiber product can be met.

Description

Technical Field

[0001] The invention belongs to the field of polymer synthesis and provides a polymerization method for regulating the molecular weight of polyketone. Background Art

[0002] Polyketone (PK), as a product of copolymerization of olefins and carbon monoxide, is a highly crystalline new type of engineering plastic with good industry development prospects. It can be used as both an engineering plastic and a special fiber material. As early as the 1990s, Shell had achieved industrial production of polyketone. The main markets for polyketone products are aerosol valves, automotive parts, oil production pipes and other fields. Due to its special molecular structure, polyketone can withstand most chemical reagents except strong acids and alkalis, and its chemical corrosion resistance is much better than PA66. Polyketone will not cause dimensional deformation due to frictional heat generation, has long-term dimensional stability, low friction noise, and is a new type of engineering plastic with outstanding wear resistance. The wear resistance of polyketone is 14 times that of polyoxymethylene (POM). It can be used to replace POM, nylon 66 and other materials, which can increase the service life of the product and reduce noise to a certain extent. Therefore, polyketone is a green and environmentally friendly material suitable for a variety of uses.

[0003] The molecular weight of polyketone is one of its most important properties. Different molecular weights are the key to producing products suitable for different purposes. The appropriate molecular weight can give polyketone injection plasticity, making it suitable for traditional injection molding and extrusion molding without affecting the mechanical properties. At the same time, high-molecular-weight polyketone products can be used for solution spinning into polyketone fiber products, and can obtain better impact resistance, expanding its application as a super-strong fiber material in high-strength tires and bulletproof vests.

[0004] In previous patent reports, the molecular weight of polyketone is mostly around 60 kg mol -1 to 200 kg mol -1 The molecular weight of polyketone is usually adjusted by lowering the polymerization temperature and replacing the reaction solvent with a higher cost (such as tert-butyl alcohol), which is often accompanied by a decrease in catalytic activity. In addition, there are patent reports that a high molecular weight polyketone is obtained by improving the feeding method of the reactor and circulating the gas from the upper part of the reactor into the disperser at the bottom of the reactor through a compressor, but the molecular weight can only reach 320 kg mol -1(Yellow River Delta Jingbo Chemical Research Institute Co., Ltd. A high molecular weight aliphatic polyketone and its synthesis method: China, CN 114106318 B[P]. 2023,04,18.). These schemes undoubtedly increase the production cost and cannot achieve a large-scale regulation of the molecular weight. The purpose of the present invention is to provide a simple and effective polymerization method for regulating the molecular weight of polyketone, using a metal nickel complex as a catalyst, and only by adding a chain transfer agent and a stabilizer, propylene, ethylene and CO copolymerization can be catalyzed to achieve a molecular weight of 10 kg mol polyketone polymer. -1 to 2000 kg mol -1 Large-scale regulation between. Summary of the invention

[0005] One of the main purposes of the present invention is to provide a method for regulating the molecular weight of polyketone, by using a cheap nickel complex to catalyze the copolymerization of ethylene, propylene and carbon monoxide (CO), the molecular weight of the obtained polyketone can be controlled within 10 kg mol -1 to 2000kgmol -1 It can be regulated between the two and is suitable for various processing methods such as injection molding and extrusion molding to produce polyketone products suitable for different purposes.

[0006] The technical solution of the present invention:

[0007] A polymerization method for regulating the molecular weight of polyketone, comprising the following steps:

[0008] Carbon monoxide and olefins are polymerized in a nickel complex catalyst, a chain transfer agent and a stabilizer solvent to obtain polyketone polymers of different molecular weights. The synthesis route is as follows:

[0009]

[0010] Under an inert atmosphere, a catalyst, a chain transfer agent, a stabilizer and a solvent are sequentially added into a reactor, the reactor is connected to a polymerization pipeline, a certain mass of propylene is first charged, and then a mixed gas of ethylene and CO with a molar ratio of (1-50):1 is charged, the reaction pressure is controlled to be 2-10MPa, the heating temperature is 50-120°C, and the reaction time is 1-48h; the reaction is stopped, and a white solid is obtained after washing with methanol, which is a polyketone polymer. The number average molecular weight thereof is between 10-2000kg / mol and the molecular weight distribution is between 1.01-3.00 as tested by gel permeation chromatography.

[0011] The structure of the catalyst is:

[0012]

[0013] In the formula, the counter anion X = BF 4- PF 6- , SbF6- , BArF - One of them.

[0014] The solvent is one or a mixture of two or more of dichloromethane, n-hexane, tetrahydrofuran, benzene, toluene, chlorobenzene, chloroform, tetrachloroethane and acetone.

[0015] The concentration of the catalyst in the reaction system is 0.01 to 5 mmol L -1 .

[0016] The stabilizer is one or a mixture of two or more of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl free radical), monoperoxyphthalic acid, ferric chloride, tin chloride, cupric chloride, cobalt chloride, o-benzoquinone, p-benzoquinone, anthraquinone, naphthoquinone, tetrachlorobenzoquinone, tetramethylbenzoquinone, and manganese dioxide.

[0017] The chain transfer agent is one or a mixture of two or more of alcohol, hydrogen, trimethylsilyl hydride, triphenylsilyl hydride, phenylsilane, triethylsilane, dimethyl monochlorosilane, 9-boranobicyclo[3,3,1]-nonane, lithium triisobutylborohydride, sodium trimethoxyborohydride, and pinacol borane.

[0018] The alcohol is one or a mixture of two or more of methanol, ethanol, isopropanol, n-butanol, tert-butanol, propylene glycol, glycerol, benzyl alcohol, and hexafluoroisopropanol.

[0019] The reaction process requires stirring, and the stirring speed is 100-500r / min.

[0020] The molar ratio of propylene, carbon monoxide and ethylene is (1-100):1:(1-50).

[0021] The molar ratio of the stabilizer to the catalyst is (1-100):1.

[0022] The molar ratio of the chain transfer to the catalyst is (10-1000):1.

[0023] Beneficial effects of the present invention:

[0024] (1) Using cheap and readily available bulk industrial products such as ethylene and carbon monoxide as raw materials, directly prepare polyketone polymer materials with high added value and excellent performance;

[0025] (2) The number average molecular weight of the obtained polyketone polymer is greater than 80,000 and less than 200,000, which satisfies the requirement that the polyketone engineering plastic is suitable for processing by injection molding and extrusion molding;

[0026] (3) The number average molecular weight of the obtained polyketone polymer is greater than 900,000, which meets the application prospect of polyketone for solution spinning into polyketone super-strong fiber products;

[0027] (4) A series of polyketone polymer materials with controllable molecular weight and melting point that meet various application requirements are directly prepared through ternary copolymerization;

[0028] (5) The polyketone materials of the present invention with different molecular weights can be simply and effectively prepared under mild conditions in the presence of a specific nickel catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the H-NMR spectrum of polyketone polymer;

[0030] Figure 2 This is a molecular weight test chart of polyketone polymer. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0032] In the preparation method provided by the present invention, the reactor used to achieve the polymerization reaction is not particularly limited, as long as the desired polymerization reaction can be achieved. Preferably, the polymerization reaction of the present invention is carried out in an autoclave. More preferably, the reactor is in an inert atmosphere such as nitrogen or argon atmosphere. Typically, the reaction temperature of the reactor can be provided by an oil bath or an electric heating system.

[0033] The data given in the examples include the specific process and parameters of the terpolymerization. The polymerization process is carried out in an inert atmosphere or environment without water or oxygen. All sensitive substances are stored in a glove box or refrigerator at -30°C. All solvents are strictly dried to remove water and oxygen. Unless otherwise specified, all other raw materials are used directly after purchase.

[0034] In the preparation method provided by the present invention, the amount of the catalyst is preferably 10 to 1000 μmol, specifically 10 μmol, 20 μmol, 50 μmol, 100 μmol, 200 μmol, 500 μmol, 1000 μmol; the solvent can be one or a mixture of two or more of dichloromethane, n-hexane, tetrahydrofuran, benzene, toluene, chlorobenzene, chloroform, tetrachloroethane or acetone; the stabilizer can be TEMPO (2,2,6,6-tetramethylpiperidinium- 1-oxygen free radical), monoperoxyphthalic acid, ferric chloride, tin chloride, cupric chloride, cobalt chloride, o-benzoquinone, p-benzoquinone, anthraquinone, naphthoquinone, tetrachlorobenzoquinone, tetramethylbenzoquinone and manganese dioxide, or a mixture of two or more thereof; the chain transfer agent may be one or a mixture of two or more thereof selected from alcohol, hydrogen, trimethylsilyl hydride, triphenylsilyl hydride, phenylsilane, triethylsilane, dimethyl monochlorosilane, 9-borabicyclo[3,3,1]-nonane, lithium triisobutylborohydride, sodium trimethoxyborohydride and pinacol borane.

[0035] In the preparation method provided by the present invention, after obtaining the solvent containing the above substances, the reaction gas is charged into the reactor to carry out the polymerization reaction. The preferred mass of propylene is 0-50g, specifically 0g, 5g, 10g, 15g, 20g, 25g, 30g, 35g, 40g, 45g and 50g; the preferred molar ratio of ethylene, propylene and carbon monoxide is (1-50):(1-100):1, specifically 1:1:1, 2:2:1, 2:4:1, 2:10:1, 2:50:1, 2:100:1, 10:50:1 or 50:50:1; the polymerization reaction pressure is preferably 2-10MPa, specifically 2MPa, 3MPa a, 4MPa, 6MPa or 10MPa, the pressure of the polymerization reaction is provided by the reaction gas charged into the reactor; the polymerization reaction temperature is preferably 50-120°C, specifically 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C; the stirring speed of the polymerization reaction is preferably 100-500r / min, specifically 100r / min, 200r / min, 250r / min, 300r / min, 400r / min or 500r / min; the polymerization reaction time is preferably 1-48h, specifically 1h, 2h, 3h, 5h, 10h, 20h, 30h or 48h.

[0036] In the preparation method provided by the present invention, after the polymerization reaction is completed, methanol is preferably added to quench the reaction and precipitate the product, and the obtained reaction product is the polyketone material synthesized by the present invention. Then the polyketone is filtered out from the solvent, washed and dried for use. The drying temperature is preferably 60 to 90°C, specifically 60°C, 70°C, 80°C or 90°C; the drying time is preferably 1 to 24h, specifically 1h, 2h, 3h, 4h, 5h or 24h.

[0037] For the purpose of greater clarity, a detailed description is given below through the following embodiments.

[0038] Embodiment 1:

[0039] In a 300mL high-pressure reactor, 50mL of solvent, 16.02mg of catalyst, stabilizer and chain transfer agent were added. After the above substances were added, the reactor was connected to the gas pipeline, and then propylene and ethylene / CO mixed gas were charged. Under this condition, the propylene / ethylene / CO partial pressure ratio was 1:1:1. The temperature was started to rise, the temperature was set to 90°C, and the stirring speed was 400r / min. When the temperature rose to 90°C, the ethylene / CO mixed gas was continuously introduced to maintain the reaction pressure at 4.0MPa. The reaction was stopped, the polymer was washed with methanol and dried in a vacuum drying oven at 60°C for 5h to obtain a white polymer product, the mass of which was weighed to calculate the conversion number, the molecular weight and distribution of the polymer were determined by gel permeation chromatography, and the molecular weight of the polymer was determined by Varian INOVA-400MHz. 1 HNMR was used to obtain the propylene / CO unit content, and differential scanning calorimetry was used to test the melting point. The data obtained are shown in Table 1. The addition of different chain transfer agents has different effects on the molecular weight of the obtained polymer, and the molecular weight of the polymer can range from 60–1110 kg mol -1 within the range of .

[0040] Table 1. Nickel-catalyzed terpolymerization of propylene, ethylene and CO

[0041]

[0042] Note 1: Polymerization conditions: reaction temperature 100°C, propylene mass 10g, ethylene / CO partial pressure ratio 1 / 1, total pressure 4.0MPa, catalyst Ni-1=10μmol, stabilizer 500μmol, solvent volume 50mL, reaction time 3h;

[0043] Note 2: The unit of conversion number is g PK (g Ni) -1 .

[0044] Embodiment 2:

[0045] In a 300mL high-pressure reactor, 50mL of solvent (the total volume of the reaction solvent and alcohol is 50mL), 16.02mg of nickel complex, chain transfer reagent, and stabilizer are added. After the above substances are added, the reactor is connected to the gas pipeline, and then propylene and ethylene / CO mixed gas are charged. Under this condition, the propylene / ethylene / CO partial pressure ratio is 1:1:1. The temperature is started to rise, the temperature is set to 90°C, and the stirring speed is 400r / min. When the temperature rises to 90°C, the ethylene / CO mixed gas with a partial pressure ratio of 1:1 is continuously introduced to maintain the reaction pressure at 4.0MPa; the reaction is stopped, the polymer is washed with methanol and dried in a vacuum drying oven at 60°C for 5h to obtain a white polymer product, its mass is weighed to calculate the conversion number, the polymer molecular weight and its distribution are determined by gel permeation chromatography, and its1 HNMR was used to obtain the propylene / CO unit content, and differential scanning calorimetry was used to test its melting point. The data obtained are shown in Table 2. The addition of different stabilizers also has different effects on the molecular weight of the obtained polymer, and the molecular weight of the polymer can range from 80–1000 kg mol -1 within the range of .

[0046] Table 2. Nickel-catalyzed terpolymerization of propylene, ethylene and CO

[0047]

[0048] Note 1: Polymerization conditions: reaction temperature 80°C, propylene mass 10g, ethylene / CO partial pressure ratio 1 / 1, total pressure 4.0MPa, catalyst Ni-1=10μmol, dichloromethane volume 50mL, chain transfer agent / catalyst=500 / 1, reaction time 3h;

[0049] Note 2: The unit of conversion number is g PK (g Ni) -1 .

[0050] Embodiment three:

[0051] In a 300mL high-pressure reactor, 50mL of solvent (the total volume of the reaction solvent and alcohol is 50mL), 16.02mg of nickel complex, and 32.4mg of p-benzoquinone were added. After the above substances were added, the reactor was connected to the gas pipeline, and then filled with propylene and a mixed gas of ethylene / CO. The temperature began to rise, the temperature was set to 90°C, and the stirring speed was 400r / min. When the temperature rose to 90°C, the mixed gas of ethylene / CO was continuously introduced to maintain the reaction pressure at 4.0MPa. The reaction was stopped, the polymer was washed with methanol and dried in a vacuum drying oven at 60°C for 5h to obtain a white polymer product, the mass of which was weighed to calculate the conversion number, the molecular weight and distribution of the polymer were determined by gel permeation chromatography, and the molecular weight of the polymer was determined by Varian INOVA-400MHz. 1 HNMR was used to obtain the propylene / CO unit content, and the melting point was tested by differential scanning calorimetry. The obtained data are shown in Table 3. Different reaction solvents, propylene / ethylene / CO partial pressures, total reaction pressure, reaction time, catalyst concentration and other conditions have basically no effect on the molecular weight of the obtained polymer, and only affect the polymerization reaction conversion number, indicating that the chain transfer agent and stabilizer have universal adaptability to reaction solvents, propylene / ethylene / CO partial pressures, total reaction pressure and other conditions.

[0052] Table 3. Nickel-catalyzed terpolymerization of propylene, ethylene and CO

[0053]

[0054]

[0055] Note 1: Polymerization conditions: reaction temperature 90°C, total pressure 4.0 MPa, catalyst Ni-1 = 10 μmol, chain transfer agent / catalyst = 500 / 1, stabilizer 500 μmol, solvent volume 50 mL, reaction time 3 h;

[0056] Note 2: The unit of conversion number is g PK (g Ni) -1 .

[0057] Note 3: The total reaction pressure of sequence 9 is 2 MPa.

[0058] Note 4: The reaction temperature of sequence 12 is 50°C.

[0059] Note 5: The reaction temperature of sequence 13 is 120°C.

[0060] Note 6: The reaction time of sequence 14 is 48h.

[0061] Note 7: The catalyst of sequence 15 is Ni-2=10 μmol.

[0062] Note 8: The catalyst of sequence 16 is Ni-1 = 1000 μmol, the reactor volume is 3 L, and the solvent volume is 2 L. Note 9: The reaction time of sequence 17 is 1 h.

Claims

1. A polymerization method for regulating the molecular weight of polyketone, characterized in that: Here are the steps: Carbon monoxide and olefins are polymerized in a nickel complex catalyst, a chain transfer agent and a stabilizer solvent to obtain polyketone polymers of different molecular weights. The synthesis route is as follows: Under an inert atmosphere, a catalyst, a chain transfer agent, a stabilizer and a solvent are sequentially added into a reactor, the reactor is connected to a polymerization pipeline, a certain mass of propylene is first charged, and then a mixed gas of ethylene and CO with a molar ratio of (1-50):1 is charged, the reaction pressure is controlled to be 2-10MPa, the heating temperature is 50-120°C, and the reaction time is 1-48h; the reaction is stopped, and a white solid is obtained after washing with methanol, which is a polyketone polymer. The number average molecular weight thereof is between 10-2000kg / mol and the molecular weight distribution is between 1.01-3.00 as tested by gel permeation chromatography.

2. The polymerization method according to claim 1, characterized in that The structure of the catalyst is: In the formula, the counter anion X = BF4 - PF6 - 、SbF6 - , BArF - One of; The concentration of the catalyst in the reaction system is 0.01 to 5 mmol L -1 .

3. The polymerization method according to claim 1, characterized in that The solvent is one or a mixture of two or more of dichloromethane, n-hexane, tetrahydrofuran, benzene, toluene, chlorobenzene, chloroform, tetrachloroethane and acetone.

4. The polymerization method according to claim 1, characterized in that The stabilizer is one or a mixture of two or more of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl free radical), monoperoxyphthalic acid, ferric chloride, tin chloride, cupric chloride, cobalt chloride, o-benzoquinone, p-benzoquinone, anthraquinone, naphthoquinone, tetrachlorobenzoquinone, tetramethylbenzoquinone, and manganese dioxide.

5. The polymerization method according to claim 1, characterized in that The chain transfer agent is one or a mixture of two or more of alcohol, hydrogen, trimethylsilyl hydride, triphenylsilyl hydride, phenylsilane, triethylsilane, dimethyl monochlorosilane, 9-boranobicyclo[3,3,1]-nonane, lithium triisobutylborohydride, sodium trimethoxyborohydride, and pinacol borane.

6. The polymerization method according to claim 5, characterized in that The alcohol is one or a mixture of two or more of methanol, ethanol, isopropanol, n-butanol, tert-butanol, propylene glycol, glycerol, benzyl alcohol, and hexafluoroisopropanol.

7. The polymerization method according to claim 1, characterized in that The molar ratio of propylene, carbon monoxide and ethylene is (1-100):1:(1-50).

8. The polymerization method according to claim 1, characterized in that The molar ratio of the stabilizer to the catalyst is (1-100):

1.

9. The polymerization method according to claim 1, characterized in that The molar ratio of the chain transfer to the catalyst is (10-1000):

1.

10. The polymerization method according to claim 1, characterized in that The reaction process requires stirring, and the stirring speed is 100-500r / min.

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