A nickel complex for synthesizing a polyketone resin, a preparation method and applications thereof

Abstract

The application belongs to the field of polymer synthesis, and discloses a nickel complex for synthesizing polyketone resin, a preparation method and application. The method directly prepares high-value-added and excellent-performance polyketone polymer materials by using cheap and easily-obtained ethylene and carbon monoxide as raw materials; the catalyst synthesis method is simple, the price is low, the polymerization reaction temperature is close to the industrial temperature of about 50 DEG C, the polymer post-treatment separation process is simple, and the conversion number of the reaction reaches 10 4 g PK(g of Ni) ‑1 The mild reaction condition reduces the requirements for technical parameters and safety factors of the reaction device; the number average molecular weight of the polyketone resin is between 0.5-7*10 5 g / mol, the molecular weight distribution is in the range of 1.0-2.1, and the molecular weight requirement of the polyketone engineering plastic is met. Under the total pressure of 4.0 MPa of ethylene / CO, the stability lasts for 3 hours, and the method has industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of polymer synthesis, and relates to a method for synthesizing and using a nickel phosphonate sulfonate catalyst. It provides a nickel complex for synthesizing polyketide resins, its preparation method, and its application. The nickel catalyst exhibits high stability and catalytic activity, and can effectively control the molecular weight of polyketides. Under the catalysis of an inexpensive nickel complex, ethylene, one or more C3-C20 olefins, and carbon monoxide undergo a polymerization reaction to prepare polyketide polymers. Background Technology

[0002] Polyethylene, a commonly used thermoplastic material in industry, possesses many excellent properties, including high strength, high chemical stability, and corrosion resistance, making it widely used in films, pipes, automobiles, machinery, and wires and cables. However, the simple hydrocarbon chemical composition of polyethylene also makes it very stable in the environment, inevitably leading to the problem of polymeric waste pollution during its large-scale application. Carbon monoxide (CO) is an important C1 resource, and ethylene is a cheap and readily available industrial raw material. Directly preparing high-value-added polyketide resin (PK) materials through metal-catalyzed copolymerization can not only effectively conserve petroleum resources but also rationally and efficiently utilize chemical resources and CO byproducts generated in other chemical processes, which is of great significance to the development of green chemistry. Polyketide resin, as a non-toxic and highly crystalline novel functional polymer material, possesses excellent impact resistance, chemical corrosion resistance, wear resistance, and gas barrier properties, and is widely used in aerospace, automotive, polymer pharmaceuticals, and textile fibers, among other fields. Shell had already commercialized polyketone production as early as 1996, and in 2005, the South Korean Hysung Group also successively developed a variety of polyketone products (David, V. Finding Openings for Polyketone Compounds; PlasticsNewsEurope, 2015). Ethylene, as the simplest and cheapest olefin, is widely studied in industry for its copolymerization with carbon monoxide to produce polyketone polymers. However, the most efficient catalysts for this reaction are palladium complexes. For example, the highly efficient industrial catalyst, a cationic palladium complex system chelated with bisphosphine ligands, can achieve a TOF (time-to-activity) of 6000 g pk (g of Pd) for polyketone preparation. -1 h -1 Furthermore, the number of transformations (TON) can reach as high as 10. 6 g PK(g of Pd) -1(Drent, E.; Budzelaar, PHMP Palladium-catalyzed alternating copolymerization of alkenes and carbonmonoxide. Chem. Rev. 1996, 96, 663-681). The development of palladium phosphonate catalysts is another major breakthrough in the field of ethylene / CO polymerization. This catalyst has an electronically asymmetric structure, possessing both a strong σ-donating phosphine end and a weak σ-donating sulfonate ester end, exhibiting good thermal stability. It has been widely used in olefin carbonylation polymerization and can copolymerize at high temperatures (80-100℃) with high activity, yielding polyketides with molecular weights as high as 370 kg mol. -1 (Hearley AK; Nowack RJ; Rieger B. New Single-Site Palladium Catalysts for the Nonnalternating Copolymerization of Ethylene and Carbon Monoxide. Organometallics, 2005, 24: 2755-2763). However, the main drawback of this production technology is the requirement for expensive palladium catalysts, which suffer from the problems of easy reduction and deactivation of divalent palladium ions and the difficulty in recovering the precious palladium metal. Nickel, like palladium, belongs to Group VIII elements and is a cheaper alternative metal, as well as the most promising post-transition metal catalyst for industrialization. However, due to the high electrophilicity of the nickel metal center in the complex, it is particularly prone to forming 5-coordinated 18-electron chelate dormant species, making it difficult to continue the ethylene insertion reaction, resulting in low activity (<10) of most nickel catalysts. 3 g PK(gof Pd) -1 h -1 It exhibits poor stability (deactivation within 10 minutes), a significant difference between its operating temperature and industrial operating temperature (suitable for room temperature reactions, rapid decomposition upon temperature increase), and a low conversion number (<10). 3 g PK(g of Pd) -1The polyketone polymer has high operating pressure (mixed gas pressure > 5 MPa). Furthermore, the melting temperature of a fully alternating ethylene / CO polyketone is 260°C, while its decomposition temperature is only 270°C. This narrow temperature window increases the difficulty and cost of processing polyketone polymers. Simultaneously, this type of polyketone has poor solubility in most organic and inorganic solvents, leading to significantly increased processing costs for injection molding and spin coating, requiring specialized processing methods. The purpose of this invention is to provide a polyketone resin and its preparation method, by adding C3-C20 olefins to break the strong dipole interaction between carbonyl groups in the polyketone molecular chain, thereby lowering the melting temperature of the polyketone to broaden its processing window and improve its processability. The content of C3-C20 units / CO in the entire polyketone polymer is determined by the feed ratio of ethylene and C3-C20. For example, the addition of 4% propylene / CO units will lower its melting point to ~230°C, which increases the processable temperature window of the polyketone resin and reduces its processing cost. Meanwhile, since nickel phosphonate catalysts have been rarely reported in the field of ethylene / CO polymerization, we designed and synthesized a series of nickel phosphonate catalysts and successfully applied them to copolymerization reactions. Summary of the Invention

[0003] The primary objective of this invention is to provide a method for synthesizing nickel phosphonate complexes.

[0004] The second objective of this invention is to provide a polyketone resin material and a method for preparing the same.

[0005] The technical solution of the present invention:

[0006] A nickel complex for synthesizing polyketone resin has the following structure:

[0007] Among them, Ar 1 and Ar 2 The following are listed: phenyl, 2-methoxyphenyl, 4-methoxyphenyl, 2,4-dimethoxyphenyl, 2,6-dimethoxyphenyl, 2,4,6-trimethoxyphenyl, 2,4-diethoxyphenyl, 2,6-diethoxyphenyl, 2,4,6-triethoxyphenyl, tert-butyl, isopropyl, ethyl, methoxy, ethoxy, cyclohexyl, 2-N,N-dimethylaminophenyl, 4-N,N-dimethylaminophenyl, 2,4-diN,N-dimethylaminophenyl, 2,6-diN,N-dimethylaminophenyl, 2-methoxy-4-N,N-dimethylaminophenyl, 2,6-dimethoxy-4-N,N-dimethylaminophenyl, 2,6-dimethoxy-1,1'-biphenyl, 2,4,6-dimethoxy-1,1'-biphenyl, Ar 1 and Ar 2 Same or different;

[0008] R 1 For H, Me,t Bu、O n Bu, NMe2, NEt2, SiMe3, C6F5, N n Bu2 or CF3;

[0009] R 2 It can be Me, Ph, or allyl;

[0010] L represents DMSO, PPh3, Py, TMEDA, MeCN, and 2,6-dimethylpyridine.

[0011] When R 2 When it is allyl, L does not exist.

[0012] A method for preparing the nickel complex, comprising the following steps:

[0013] 1) Benzenesulfonic acid A, phosphonic chloride B and n-butyllithium in a molar ratio of 1:1:(0.5-2.5) are reacted in an organic solvent at room temperature for 6-36 hours to form phosphonic acid ligand C; wherein the concentration of benzenesulfonic acid A in the reaction system is 1 mol / L;

[0014]

[0015] 2) At room temperature, phosphonic acid ligand C with a molar ratio of 1:(0.5~1.1) and [Ni(allyl)Cl]2 are reacted in an organic solvent for 2-24 hours to obtain nickel phosphonic acid sulfonate complex D; wherein the concentration of phosphonic acid ligand C in the reaction system is 0.02mol / L;

[0016]

[0017] 3) At room temperature, phosphonic acid ligand C with a molar ratio of 1:(0.5~1.5) and Py2NiMe2 or [NiCl(Ph)(PPh3)2] are reacted in an organic solvent for 2-24 hours to obtain nickel phosphonic acid sulfonate complex E; wherein the concentration of phosphonic acid ligand C in the reaction system is 0.02mol / L;

[0018]

[0019] The organic solvent is one or a mixture of two or more of toluene, xylene, diethyl ether, methyl tert-butyl ether, n-hexane, dioxane, dilute hydrochloric acid, methanol, ethanol, and tetrahydrofuran.

[0020] A method for preparing polyketone resin using the above-mentioned nickel complex, wherein the structure of the polyketone resin is as follows:

[0021]

[0022] Where n and m are the degree of polymerization; 10 <n<105 , 0≤m<10 3 0≤m / (n+m)<50%;

[0023] R is an olefin within C3-C20, including propylene, 1-butene, 1-hexene, 1-octene, and 1-decene;

[0024] The steps are as follows: the reaction temperature range is 20℃~150℃; the total pressure of ethylene, C3-C20 olefins and carbon monoxide ranges from 0.4MPa to 6.0MPa; wherein the partial pressure of ethylene is in the range of 5%-95% of the total pressure, and the molar ratio of C3-C20 olefins to ethylene is not greater than 2; the mixture of carbon monoxide, ethylene and C3-C20 olefins is brought into contact in a solvent capable of dissolving the nickel complex catalyst; the concentration of the nickel complex catalyst used is between 0.001mol / L and 1mol / L, and the reaction time is between 5min and 6h.

[0025] The solvent used is one or a mixture of two or more of the following: toluene, benzene, dichloromethane, methanol, methyl tert-butyl ether, diethyl ether, chlorobenzene, n-hexane, cyclohexane, n-pentane, tetrahydrofuran, ethylene glycol dimethyl ether, dimethyl sulfoxide, chloroform, and 1,4-dioxane.

[0026] The specific synthetic route of polyketone resin is as follows:

[0027]

[0028] The beneficial effects of this invention are:

[0029] (1) Using cheap and readily available bulk industrial products ethylene and carbon monoxide as raw materials, high-value-added and high-performance polyketone resin materials are directly prepared.

[0030] (2) It uses inexpensive nickel complexes as raw materials, does not require expensive precious metal catalysts, and has a simple catalyst synthesis method;

[0031] (3) The reaction temperature is close to the industrial temperature of ~50℃, and the polymer post-processing and separation process is simple;

[0032] (4) The activity of the nickel catalyst is as high as 10 4 g PK(g of Ni) -1 h -1 The catalyst has a conversion number of 10. 4 g PK(g ofNi) -1 It has great potential for industrial applications;

[0033] (5) Under a total ethylene / CO pressure of 4.0 MPa, its stability lasts for up to 3 hours; the catalyst can maintain high catalytic activity and stability even at a high temperature of 120℃;

[0034] (6) Nickel catalysts also have high catalytic activity and conversion number for the ternary copolymerization reaction of ethylene / C3-C20 olefin / CO, and can control the content of propylene / CO units in polyketide, thereby achieving the regulation of the melting point of polyketide resin materials.

[0035] (7) The number average molecular weight of polyketone resin materials is between 0.5 and 7 × 10⁻⁶. 5 The molecular weight distribution is between 1.0 and 2.1 g / mol, which meets the molecular weight requirements for polyketide engineering plastics. Attached Figure Description

[0036] Figure 1 This is the 1H NMR spectrum of the nickel catalyst according to Example 2 of the present invention.

[0037] Figure 2 This is the NMR phosphine spectrum of the nickel catalyst according to Example 2 of the present invention.

[0038] Figure 3 This is the 1H NMR spectrum of alternating polyketides prepared by ethylene / carbon monoxide copolymerization according to Example 6 of the present invention.

[0039] Figure 4 This is the carbon NMR spectrum of alternating polyketides prepared by ethylene / carbon monoxide copolymerization according to Example 6 of the present invention. Detailed Implementation

[0040] The specific embodiments of the present invention are described in detail below with reference to the technical solutions and accompanying drawings. Examples are given of methods for the synthesis and polymerization of ligands and complexes. The synthesis and polymerization processes of the complexes are carried out under anhydrous and oxygen-free conditions; all sensitive pharmaceuticals are stored in glove boxes; and all solvents are rigorously dried and dehydrated. Unless otherwise specified, all raw materials are used directly after purchase.

[0041] Example 1:

[0042] The synthesis of 2-(bis(2,6-dimethoxyphenyl)phosphino)benzenesulfonic acid (L-4OMe) is shown in the following reaction formula:

[0043]

[0044] Under nitrogen protection, benzenesulfonic acid (3.16 g, 20 mmol), chlorobis(2,6-dimethoxyphenyl)phosphine (6.8 g, 20 mmol), 20 mL of tetrahydrofuran, and 2 equivalents of n-butyllithium were added to a 100 mL round-bottom flask, and the reaction was carried out at room temperature for 36 hours. After the reaction was completed, the solution was acidified with dilute hydrochloric acid to pH 2, and the solvent was removed under reduced pressure. The solution was extracted with dichloromethane (20 mL × 2) and water, and the organic phase was dried over anhydrous Na₂SO₄. After filtration and removal of the solvent under reduced pressure, recrystallization in dichloromethane yielded the target product L-4OMe as a white solid (0.72 g, 78%).1 H NMR (400MHz, CDCl3) δ8.37–8.28(m,1H),7.69–7.63(m,1H),7.52(t,J=8.4Hz,2H ), 7.38 (dd, J=11.7, 4.0Hz, 2H), 6.60 (dd, J=8.5, 5.2Hz, 4H), 3.63 (s, 12H, OMe). 31 P NMR (162MHz, CDCl3) δ -29.85.

[0045] Example 2:

[0046] The synthesis of the nickel metal complex (Ni-4OMe) has the following structural formula:

[0047]

[0048] Under N2 protection, ligand L-4OMe (1.85 g, 4 mmol), [Ni(allyl)Cl]2 (648 mg, 2.4 mmol), and Na2CO3 (1.06 g, 10 mmol) were stirred in 20 mL of CH2Cl2 at room temperature for 24 h. After the reaction was completed, the filtrate was concentrated to a certain volume, washed with n-hexane (20 mL × 2), and dried under vacuum to obtain a brownish-yellow powder Ni-4OMe (2.2 g, 98%). 1 H NMR (600MHz, CDCl3) δ8.07 (s, 1H), 7.37 (d, J = 44.6Hz, 4H), 7.20 (s, 1H), 6.54 (s, 4H) ),5.49(s,1H,allyl),3.65(s,12H,OMe),2.93(s,2H,allyl),2.20(s,2H,allyl). 31 P NMR (243MHz, CDCl3) δ -28.39.

[0049] Example 3:

[0050] The synthesis of the nickel complex (Ni-4OMe-PPh3) has the following structural formula:

[0051]

[0052] Under N2 protection, ligand L-4OMe (1.85 g, 4 mmol), trans-[NiCl(Ph)(PPh3)2] (2.78 g, 4 mmol), and Na2CO3 (1.06 g, 10 mmol) were stirred in 20 mL of CH2Cl2 at room temperature for 24 h. After the reaction was completed, the filtrate was concentrated to a certain volume, washed with n-hexane (20 mL × 2) and diethyl ether (20 mL × 3), and dried under vacuum to obtain a bright yellow powder Ni-4OMe-PPh3 (2.8 g, 81%).

[0053] Example 4:

[0054] The synthesis of the nickel metal complex (Ni-4OMe-Lut) has the following structural formula:

[0055]

[0056] Under N2 protection, ligand L-4OMe (1.85 g, 4 mmol), Py2NiMe2 (0.98 g, 4 mmol), and 0.5 mL of 2,6-dimethylpyridine were reacted in 20 mL of THF at -30 °C for 24 h with stirring. After the reaction was completed, the filtrate was concentrated to a certain volume, washed with n-hexane (20 mL × 2), and dried under vacuum to obtain a bright yellow powder Ni-4OMe-Lut (1.9 g, 74%).

[0057] Example 5:

[0058] The synthesis of the nickel complex (Ni-4OMe-Py) has the following structural formula:

[0059]

[0060] Under N2 protection, ligand L-4OMe (1.85 g, 4 mmol), Py2NiMe2 (1.48 g, 6 mmol), and Na2CO3 (1.06 g, 10 mmol) were stirred in 20 mL of THF at -30 °C for 24 h. After the reaction was complete, the filtrate was concentrated to a certain volume, washed with n-hexane (20 mL × 2) and diethyl ether (20 mL × 2), and dried under vacuum to obtain a bright yellow powder Ni-4OMe-Py (2.1 g, 85%).

[0061] Example 6:

[0062] In a 100 mL stainless steel autoclave, at ambient temperature, the following ingredients were added in sequence: a certain amount of Ni catalyst (any metal complex described in the claims), with a loading between 1 and 100 μmol; a certain amount of solvent and a magnetic stir bar, with a solvent volume between 10 and 60 mL; an ethylene / carbon monoxide mixture at a specified pressure was introduced and rapidly raised to the set temperature, which was 20°C to 150°C, and stirring was started. The reaction time was between 5 min and 6 h. After reaching the set time, stirring was stopped, the remaining mixture was slowly released, methanol was added to quench the reaction, and then a large amount of methanol was added to precipitate the polymer. The polymer was filtered and dried under vacuum to constant weight. The polymerization results are shown in Table 1 below. The molecular weight and distribution of the polymer were determined by gel permeation chromatography; its molecular weight was determined by Varian INOVA-400MHz. 1 The structure of the polyketide was obtained by HNMR. Its melting point was determined by differential scanning calorimetry.

[0063] Table 1. Copolymerization of ethylene / carbon monoxide catalyzed by nickel complexes

[0064]

[0065]

[0066]

[0067] Note 1: Polymerization conditions: reaction temperature 80℃, ethylene / CO ratio = 2 / 1, total pressure 4.0MPa, Ni loading = 10μmol, dichloromethane = 20mL, reaction time 1h;

[0068] Note 2: Activity: g pk (g of Ni) -1 ;

[0069] Note 3: Molecular weight: kg mol -1 The molecular weight and molecular weight distribution were determined by gel permeation chromatography at 40°C, with hexafluoroisopropanol as the eluent.

[0070] Note 4: Melting temperature T of all polyketides m At ~260℃.

[0071] Example 7:

[0072] In a 100 mL stainless steel autoclave, at ambient temperature, the following ingredients were added in sequence: a certain amount of Ni catalyst (any metal complex described in the claims), with a loading between 1 and 100 μmol; a certain amount of solvent and a magnetic stir bar, with a solvent volume between 10 and 50 mL; an ethylene / carbon monoxide mixture at a specified pressure was introduced and rapidly raised to the set temperature, which was 20°C to 150°C, and stirring was started. The reaction time was between 5 min and 6 h. After reaching the set time, stirring was stopped, the remaining mixture was slowly released, methanol was added to quench the reaction, and then a large amount of methanol was added to precipitate the polymer. The polymer was filtered and dried under vacuum to constant weight. The polymerization results are shown in Table 2 below. The molecular weight and distribution of the polymer were determined by gel permeation chromatography; its molecular weight was determined by Varian INOVA-400MHz. 1 The structure of the polyketide was obtained by HNMR. Its melting point was determined by differential scanning calorimetry.

[0073] Table 2. Copolymerization of ethylene / carbon monoxide catalyzed by nickel complexes.

[0074]

[0075]

[0076] Note 1: Polymerization conditions: Ni loading = 10 μmol, total pressure 4.0 MPa, dichloromethane = 20 mL;

[0077] Note 2: Activity: g pk (g of Ni) -1 ;

[0078] Note 3: Molecular weight: kg mol -1 The number-average molecular weight (Mn) and molecular weight distribution (PDI) were determined by gel permeation chromatography at 40°C, with hexafluoroisopropanol as the eluent.

[0079] Note 4: The melting temperature Tm of all polyketones is ~260℃.

[0080] Example 8:

[0081] In a 100 mL stainless steel autoclave, at ambient temperature, the following substances were added in the following order: a certain amount of Ni catalyst (any metal complex described in the claims), with a loading of 1-100 μmol; a certain amount of solvent and a magnetic stir bar, with a solvent volume of 10-50 mL; a certain amount of C3-C20 olefin, with a mass of 0.3-7 g; an ethylene / carbon monoxide mixture at a specified pressure was introduced and rapidly raised to the set temperature, which was 20℃~150℃, and stirring was started. The reaction time was between 5 min and 6 h. After reaching the set time, stirring was stopped, the remaining mixture was slowly released, methanol was added to quench the reaction, and then a large amount of methanol was added to precipitate the polymer. The polymer was filtered and dried under vacuum to constant weight. The polymerization results are shown in Table 3 below. The molecular weight and distribution of the polymer were determined by gel permeation chromatography; its molecular weight was determined by Varian INOVA-400MHz. 1 The structure of the polyketide was obtained by HNMR. Its melting point was determined by differential scanning calorimetry.

[0082] Table 3. Copolymerization of ethylene / C3-C20 olefins / carbon monoxide catalyzed by nickel metal complexes

[0083]

[0084]

[0085] Note 1: Polymerization conditions: reaction temperature 80℃, ethylene / CO ratio = 2 / 1, total pressure 4.0MPa, Ni loading = 10μmol, dichloromethane = 20mL, reaction time 1h;

[0086] Note 2: C3-C20 insertion ratio (mol%) 1 (Measured by H NMR spectroscopy);

[0087] Note 3: Molecular weight: kg mol -1 Number average molecular weight M n The molecular weight distribution of PDI was determined by gel permeation chromatography at 40°C, with hexafluoroisopropanol as the eluent.

[0088] Note 4: Melting temperature T m Determined by differential scanning calorimetry (DSC), secondary heating, and broad melting endothermic peak.

Claims

1. A method for preparing polyketide resin from a nickel phosphonate sulfonate complex, characterized in that, The structure of polyketone resin is as follows: ； Where n and m are the degree of polymerization; 10 <n< 10 5 0 ≤ m < 10 3 0 ≤ m / (n+m) < 50%; R is an olefin within C3-C20, including propylene, 1-butene, 1-hexene, 1-octene, and 1-decene; The steps are as follows: Reaction temperature range 20°C o C~150 o C; The total pressure of ethylene, C3-C20 olefins, and carbon monoxide ranges from 0.4 MPa to 6.0 MPa; wherein the partial pressure of ethylene is in the range of 5%-95% of the total pressure, and the molar ratio of C3-C20 olefins to ethylene is not greater than 2; the mixture of carbon monoxide, ethylene, and C3-C20 olefins is contacted in a solvent capable of dissolving the nickel complex catalyst; the concentration of the nickel complex catalyst used is between 0.001 mol / L and 1 mol / L, and the reaction time is between 5 min and 6 h; The structure of the nickel complex is shown below: ; Among them, Ar 1 and Ar 2 The compounds are 2-methoxyphenyl, 2,4-dimethoxyphenyl, 2,6-dimethoxyphenyl, 2,4,6-trimethoxyphenyl, 4-N,N-dimethylaminophenyl, 2,4-diN,N-dimethylaminophenyl, 2,6-diN,N-dimethylaminophenyl, 2-methoxy-4-N,N-dimethylaminophenyl, and 2,6-dimethoxy-4-N,N-dimethylaminophenyl. Ar 1 and Ar 2 Same or different.

2. The method according to claim 1, characterized in that, The solvent used is one or a mixture of two or more of the following: toluene, benzene, dichloromethane, methanol, methyl tert-butyl ether, diethyl ether, chlorobenzene, n-hexane, cyclohexane, n-pentane, tetrahydrofuran, ethylene glycol dimethyl ether, dimethyl sulfoxide, chloroform, and 1,4-dioxane.

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