A polymerization process for controlling the molecular weight of polyketones

Abstract

The application belongs to the field of polymer synthesis, and discloses a polymerization method for regulating the molecular weight of polyketone. A series of ternary polyketone polymers with adjustable molecular weight and melting point are directly prepared by ternary copolymerization of ethylene, CO and propylene under the catalysis of a nickel catalyst and the addition of a chain transfer agent and a stabilizer. The synthesis route is simple to operate, the reaction condition is relatively mild, the molecular weight range of the obtained polyketone is wide, and the polyketone polymer material can be prepared by various processing methods for multiple purposes and multiple functions. The molecular weight of the obtained polyketone is greater than 80,000 and less than 200,000, which can meet the processing of engineering plastics by injection molding and extrusion molding. The molecular weight of the obtained polyketone is as high as 900,000 or more, which can meet the application prospect of polyketone used for solution spinning into polyketone super strong fiber products.

Description

Technical Field

[0001] This invention belongs to the field of polymer synthesis and provides a polymerization method for controlling the molecular weight of polyketides. Background Technology

[0002] Polyketone (PK), a copolymer of olefins and carbon monoxide, is a highly crystalline new type of engineering plastic with promising industry prospects. It can be used as both an engineering plastic and a specialty fiber material. Shell achieved industrial-scale production of PK as early as the 1990s. The main markets for PK products are aerosol valves, automotive parts, and oil pipelines. Due to its unique molecular structure, PK can withstand most chemical reagents except for strong acids and alkalis, exhibiting significantly better chemical corrosion resistance than PA66. PK does not deform due to frictional heat, demonstrating long-term dimensional stability and low frictional noise, making it a novel engineering plastic with outstanding wear resistance. PK's wear resistance is 14 times that of polyoxymethylene (POM), making it a suitable replacement for POM, Nylon 66, and other materials, extending product lifespan and reducing noise to some extent. Therefore, PK is a green and environmentally friendly material suitable for various applications.

[0003] The molecular weight of polyketone is one of its most important properties, and different molecular weights are key to producing products suitable for different applications. A suitable molecular weight imparts injection moldability to polyketone, making it suitable for traditional injection molding and extrusion molding without compromising its mechanical properties. Simultaneously, high molecular weight polyketone products can be solution spun into polyketone fibers, achieving superior impact resistance and expanding its application as a high-strength fiber material in fields such as high-strength tires and bulletproof vests.

[0004] In previous literature and patent reports, the molecular weight of polyketide was mostly around 60 kg / mol. -1 Up to 200kg mol -1 The molecular weight of polyketides is often increased by lowering the polymerization temperature and replacing the more expensive reaction solvent (such as tert-butanol), which often results in a decrease in catalytic activity. In addition, some patents report a method to obtain high molecular weight polyketides by improving the reactor feeding method, using a compressor to circulate gas from the top of the reactor into a disperser at the bottom, but the resulting molecular weight only reaches 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 methods undoubtedly increase production costs and cannot achieve significant molecular weight control. The purpose of this invention is to provide a simple and effective polymerization method for controlling the molecular weight of polyketones. Using a nickel complex as a catalyst, and only by adding a chain transfer agent and a stabilizer, the copolymerization of propylene, ethylene, and CO can be catalyzed, achieving a molecular weight of 10 kg mol for the polyketone polymer. -1 Up to 2000 kg mol -1 Significant adjustments were made between them. Summary of the Invention

[0005] One of the main objectives of this invention is to propose a method for controlling the molecular weight of polyketide. By using inexpensive nickel complexes to catalyze the copolymerization of ethylene, propylene, and carbon monoxide (CO), the molecular weight of the resulting polyketide can be as high as 10 kg / mol. -1 Up to 2000 kgmol -1 It can be adjusted between different processing methods, and is suitable for various processing methods such as injection molding and extrusion molding to produce polyketone products for different applications.

[0006] The technical solution of the present invention:

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

[0008] Carbon monoxide and olefins were polymerized in a solvent containing a nickel complex catalyst, a chain transfer agent, and a stabilizer to yield polyketide polymers of different molecular weights. The synthetic route is as follows:

[0009]

[0010] Under an inert atmosphere, the catalyst, chain transfer reagent, stabilizer, and solvent are sequentially added to a reactor connected to a polymerization pipeline. A certain mass of propylene is first introduced, followed by a mixture of ethylene and CO in a molar ratio of (1–50):1. The reaction is carried out at a pressure of 2–10 MPa and a heating temperature of 50–120 °C for 1–48 h. After stopping the reaction and washing with methanol, a white solid is obtained, which is the polyketide polymer. Gel permeation chromatography shows that its number-average molecular weight is between 10–2000 kg / mol, and its molecular weight distribution is between 1.01 and 3.00.

[0011] The structure of the catalyst is as follows:

[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 the following: dichloromethane, n-hexane, tetrahydrofuran, benzene, toluene, chlorobenzene, chloroform, tetrachloroethane, and acetone.

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

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

[0017] The chain transfer reagent is one or a mixture of two or more of the following: alcohol, hydrogen, trimethylsilane, triphenylsilane, benzylsilane, triethylsilane, dimethylchlorosilane, 9-boronbicyclo[3,3,1]-nonane, lithium triisobutylborohydride, sodium trimethoxyborohydride, and pinacolborane.

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

[0019] The reaction process requires stirring at a speed of 100–500 r / 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 chain transfer to catalyst is (10-1000):1.

[0023] The beneficial effects of this invention are:

[0024] (1) Using cheap and readily available bulk industrial products ethylene and carbon monoxide as raw materials, high-value-added and high-performance polyketide polymer materials are directly prepared.

[0025] (2) The number average molecular weight of polyketone polymers can be greater than 80,000 and less than 200,000, which meets the requirements that polyketone engineering plastics are suitable for injection molding and extrusion molding.

[0026] (3) The number average molecular weight of polyketone polymers is greater than 900,000, which meets the application prospects 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 can be directly prepared through ternary copolymerization reaction;

[0028] (5) The polyketone materials of different molecular weights of the present invention can be prepared simply and effectively under mild conditions in the presence of a specific nickel catalyst. Attached Figure Description

[0029] Figure 1 The 1H NMR spectrum of polyketide polymer;

[0030] Figure 2 This is a graph showing the molecular weight of polyketide polymers. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0032] In the preparation method provided by this invention, there are no particular limitations on the reactor used to carry out the polymerization reaction, as long as it can achieve the desired polymerization reaction. Preferably, the polymerization reaction of this invention is carried out in an autoclave. More preferably, the reactor is in an inert atmosphere such as nitrogen or argon. Typically, the reaction temperature of the reactor can be provided by an oil bath or an electric heating system.

[0033] The data provided in the examples include the specific process and parameters of the ternary polymerization, which is carried out in an anhydrous and oxygen-free inert atmosphere or environment. All sensitive substances are stored in a glove box or refrigerator at -30°C, and 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 this invention, the catalyst dosage is preferably 10–1000 μmol, specifically 10 μmol, 20 μmol, 50 μmol, 100 μmol, 200 μmol, 500 μmol, or 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-tetramethylpiperidine- The chain transfer reagent may be one or a mixture of two or more of the following: 1-oxygen radical, monoperoxyphthalic acid, ferric chloride, tin chloride, copper chloride, cobalt chloride, o-benzoquinone, p-benzoquinone, anthraquinone, naphthoquinone, tetrachlorobenzoquinone, tetramethylbenzoquinone, and manganese dioxide; the chain transfer reagent may be one or a mixture of two or more of the following: alcohol, hydrogen, trimethylsilane, triphenylsilane, benzylsilane, triethylsilane, dimethylmonochlorosilane, 9-boronbicyclo[3,3,1]-nonane, triisobutyl borohydride, sodium trimethoxyborohydride, and pinacolborane.

[0035] In the preparation method provided by this invention, after obtaining a solvent containing the above-mentioned substances, a reaction gas is introduced into the reaction vessel to carry out a 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 preferred polymerization reaction pressure is 2-10MPa, specifically 2MPa or 3MPa. a. The pressure of the polymerization reaction is 4 MPa, 6 MPa, or 10 MPa, provided by the reaction gas introduced 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 100–500 r / min, specifically 100 r / min, 200 r / min, 250 r / min, 300 r / min, 400 r / min, or 500 r / min; the polymerization reaction time is preferably 1–48 h, specifically 1 h, 2 h, 3 h, 5 h, 10 h, 20 h, 30 h, or 48 h.

[0036] In the preparation method provided by this invention, after the polymerization reaction is completed, methanol is preferably added to quench the reaction and precipitate the product. The resulting reaction product is the polyketide material synthesized by this invention. The polyketide is then filtered from the solvent, washed, and dried for later use. The drying temperature is preferably 60–90°C, specifically 60°C, 70°C, 80°C, or 90°C; the drying time is preferably 1–24 hours, specifically 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, or 24 hours.

[0037] For clarity, the following examples will provide a detailed explanation.

[0038] Example 1:

[0039] Add 50 mL of solvent, 16.02 mg of catalyst, stabilizer, and chain transfer reagent to a 300 mL high-pressure reactor. After adding these substances, connect the reactor to the gas pipeline, then introduce propylene and an ethylene / CO mixture. Under these conditions, the partial pressure ratio of propylene / ethylene / CO is 1:1:1. Start heating, setting the temperature to 90 °C and the stirring speed to 400 r / min. When the temperature reaches 90 °C, continuously introduce the ethylene / CO mixture to maintain the reaction pressure at 4.0 MPa. Stop the reaction, wash the polymer with methanol, and dry it in a vacuum drying oven at 60 °C for 5 h to obtain a white polymer product. Weigh the product and calculate the conversion number. Determine the molecular weight and distribution of the polymer using gel permeation chromatography, and analyze its molecular weight using Varian INOVA-400 MHz. 1 ¹H NMR was used to determine the propylene / CO unit content, and differential scanning calorimetry was used to determine its melting point. The obtained data are shown in Table 1. The addition of different chain transfer reagents had different effects on the molecular weight of the obtained polymers, ranging from 60 to 1110 kg mol. -1 Adjust within a certain range.

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

[0041]

[0042] Note 1: Polymerization conditions: reaction temperature 100℃, 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] Example 2:

[0045] Add 50 mL of solvent (total volume of solvent and alcohol is 50 mL), 16.02 mg of nickel complex, chain transfer reagent, and stabilizer to a 300 mL high-pressure reactor. After adding these substances, connect the reactor to the gas pipeline, then introduce propylene and an ethylene / CO mixture. Under these conditions, the partial pressure ratio of propylene / ethylene / CO is 1:1:1. Start heating, setting the temperature to 90 °C and the stirring speed to 400 r / min. When the temperature reaches 90 °C, continuously introduce the ethylene / CO mixture with a partial pressure ratio of 1:1, maintaining the reaction pressure at 4.0 MPa. Stop the reaction, wash the polymer with methanol, and dry it in a vacuum drying oven at 60 °C for 5 h to obtain a white polymer product. Weigh the product and calculate the conversion number. Determine the molecular weight and distribution of the polymer using gel permeation chromatography, and determine its molecular weight using Varian INOVA-400 MHz.1 HNMR was used to determine the propylene / CO unit content, and differential scanning calorimetry was used to determine its melting point. The obtained data are shown in Table 2. The addition of different stabilizers also had different effects on the molecular weight of the obtained polymers, with molecular weights ranging from 80 to 1000 kg mol. -1 Adjust within a certain range.

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

[0047]

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

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

[0050] Example 3:

[0051] Add 50 mL of solvent (total volume of solvent and alcohol is 50 mL), 16.02 mg of nickel complex, and 32.4 mg of p-benzoquinone to a 300 mL high-pressure reactor. After adding these substances, connect the reactor to the gas pipeline, then introduce propylene and an ethylene / CO mixture. Start heating, setting the temperature to 90 °C and the stirring speed to 400 r / min. When the temperature reaches 90 °C, continuously introduce the ethylene / CO mixture to maintain the reaction pressure at 4.0 MPa. Stop the reaction, wash the polymer with methanol, and dry it in a vacuum drying oven at 60 °C for 5 h to obtain a white polymer product. Weigh the product and calculate the conversion number. Determine the molecular weight and distribution of the polymer using gel permeation chromatography and analyze its molecular weight using Varian INOVA-400 MHz. 1 HNMR was used to obtain the propylene / CO unit content, and differential scanning calorimetry was used to determine its melting point. 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 little effect on the molecular weight of the obtained polymer, only affecting the polymerization conversion number. This indicates that the chain transfer reagent 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℃, total pressure 4.0MPa, catalyst Ni-1 = 10μmol, chain transfer reagent / catalyst = 500 / 1, stabilizer 500μmol, solvent volume 50mL, reaction time 3h;

[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 for sequence 12 is 50°C.

[0059] Note 5: The reaction temperature for sequence 13 is 120℃.

[0060] Note 6: The reaction time for sequence 14 is 48 hours.

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

[0062] Note 8: The catalyst for 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 for Sequence 17 is 1 h.

Claims

1. A polymerization method for controlling the molecular weight of polyketide, characterized in that, The steps are as follows: Carbon monoxide and olefins were polymerized in a solvent containing a nickel complex catalyst, a chain transfer agent, and a stabilizer to yield polyketide polymers of different molecular weights. The synthetic route is as follows: Under an inert atmosphere, the catalyst, chain transfer reagent, stabilizer, and solvent are sequentially added to a reaction vessel connected to a polymerization pipeline. A certain mass of propylene is first introduced, followed by a mixture of ethylene and CO in a molar ratio of (1~50):

1. The reaction is carried out at a pressure of 2~10 MPa and a heating temperature of 50~120 ℃ for 1~48 h. After stopping the reaction and washing with methanol, a white solid is obtained, which is the polyketide polymer. Gel permeation chromatography shows that its number-average molecular weight is between 10-2000 kg / mol, and its molecular weight distribution is between 1.01-3.

00. The stabilizer is one or a mixture of two or more of the following: TEMPO (2,2,6,6-tetramethylpiperidine-1-oxygen radical), monoperoxyphthalic acid, ferric chloride, tin chloride, copper chloride, cobalt chloride, o-benzoquinone, p-benzoquinone, anthraquinone, naphthoquinone, tetrachlorobenzoquinone, tetramethylbenzoquinone, and manganese dioxide. The chain transfer reagent is one or a mixture of two or more of the following: alcohol, hydrogen, trimethylsilane, triphenylsilane, benzylsilane, triethylsilane, dimethylchlorosilane, 9-boronbicyclo[3,3,1]-nonane, lithium triisobutylborohydride, sodium trimethoxyborohydride, and pinacolborane. The molar ratio of the stabilizer to the catalyst is (1-100):1; The molar ratio of chain transfer to catalyst is (10-1000):1; The structure of the catalyst is as follows: In the formula, the counter anion X = BF4 - PF6 - SbF6 - ,BArF - One of them; The concentration of the catalyst in the reaction system is 0.01~5 mmol L. - 1 .

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

3. The polymerization method according to claim 1, characterized in that, The alcohol is one or a mixture of two or more of the following: methanol, ethanol, isopropanol, n-butanol, tert-butanol, propylene glycol, glycerol, benzyl alcohol, and hexafluoroisopropanol.

4. 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).

5. The polymerization method according to claim 1, characterized in that, The reaction process requires stirring at a speed of 100-500 r / min.

Images