A b / p organic lewis acid-base pair catalyzing the living polymerization of renewable vinyl monomers and a catalytic polymerization process thereof

Abstract

The application provides a B / P organic Lewis acid-base pair for catalyzing active polymerization of renewable vinyl monomers and a catalytic polymerization method thereof, and belongs to the technical field of polymer synthesis.The application realizes the active polymerization of renewable vinyl monomers by the synergistic catalysis of an organic boron Lewis acid and an organic phosphine Lewis base, realizes the active and controllable homopolymerization and copolymerization of different renewable vinyl monomers by adjusting the electronic effect and steric hindrance effect of the organic boron Lewis acid and the organic phosphine Lewis base, the molecular weight of the obtained polymer increases with the increase of the monomer to catalyst ratio, and the monomer conversion rate is 100%.Meanwhile, the B / P organic Lewis acid-base pair catalyst provided by the application is simple to synthesize and easy to commercialize, and the structure is rich in adjustability.The B / P organic Lewis acid-base pair catalyst provided by the application has a small amount in the catalytic reaction and is widely applicable to renewable monomers.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer synthesis, in particular to a B / P organic Lewis acid-base pair for catalyzing active polymerization of renewable vinyl monomers and a catalytic polymerization method thereof. BACKGROUND

[0002] Polymer materials have the characteristics of small density, large specific strength, simple forming process and low cost, and are essential material basis for people's clothing, food, shelter and transportation in today's human society. However, most of the polymer materials used at present are derived from non-renewable fossil energy. In order to alleviate and solve the energy crisis, polymer scientists believe that using renewable resources to replace petroleum-based polymers is one of the effective ways. General polymer material polymethyl methacrylate (PMMA) has the characteristics of high transparency and impact resistance, and is widely used in various aspects of people's production and life. However, PMMA is a petroleum-based polymer material and is difficult to be renewable. Therefore, it is of great significance to find renewable polymer materials that can replace PMMA to solve or alleviate the problem of depletion of petroleum resources.

[0003] Lewis acid-base pair polymerization (LPP) is a new type of polymerization method developed in the past decade. In LPP, Lewis acid and Lewis base cooperatively promote the processes of monomer activation and chain initiation, chain growth and chain termination or chain transfer. Since the development of LPP, LPP has rapidly developed in the polymerization of polar vinyl monomers. Not only has the active and controllable polymerization of many polar vinyl monomers been realized, but also some difficult problems in polymer synthesis have been solved, such as the synthesis of ultrahigh molecular weight polymers, the synthesis of sequence-controllable polymers and the synthesis of cyclic polymers. However, there are still the following problems in the use of LPP to catalyze renewable monomers MBL and MMBL: (1) although efficient polymerization can be achieved, the molecular weight of the polymer is uncontrollable; (2) chain extension and block copolymerization experiments cannot be carried out; (3) the main LPP catalysts are metal-containing catalysts, and non-metallic organic catalysts are still rare. SUMMARY

[0004] Therefore, the present application aims to provide a B / P organic Lewis acid-base pair for catalyzing active polymerization of renewable vinyl monomers and a catalytic polymerization method thereof. The B / P organic Lewis acid-base pair provided by the present application can realize active and controllable polymerization of renewable vinyl monomers.

[0005] In order to achieve the above-mentioned application purpose, the present application provides the following technical solutions:

[0006] The application provides a B / P organic Lewis acid-base pair for catalyzing active polymerization of renewable vinyl monomers, which comprises an organic boron Lewis acid and an organic phosphine Lewis base; the organic boron Lewis acid has the structure shown in any one of formula I-1 to formula I-11.

[0007]

[0008] In formula I-1 to formula I-11, R1 is halogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl, pentafluorophenyl, trifluoromethyl, trimethylsilyl or tetraphenylvinyl;

[0009] R2 is hydrogen, halogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, pentafluorophenyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl, trifluoromethyl or trimethylsilyl;

[0010] R3 is hydrogen, halogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, pentafluorophenyl, trifluoromethyl or trimethylsilyl;

[0011] The organic phosphine Lewis base has the structure shown in any one of formula II-1 to formula II-3:

[0012]

[0013] In formula II-1 to formula II-3, A1 is methyl, ethyl, isopropyl, isobutyl, tert-butyl, phenyl, substituted phenyl, vinyl, allyl or alkenyl;

[0014] A2 is methyl, ethyl, isopropyl, isobutyl, tert-butyl, phenyl, substituted phenyl, vinyl, allyl or alkenyl;

[0015] A3 is hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, substituted phenyl, pentafluorophenyl, trifluoromethyl, vinyl, allyl or alkenyl.

[0016] Preferably, the molar ratio of the organic boron Lewis acid and the organic phosphine Lewis base is 1-100:1.

[0017] The application provides application of the above B / P organic Lewis acid-base pair in catalyzing active polymerization of renewable vinyl monomers.

[0018] Preferably, the renewable vinyl monomer has the structure shown in any one of formula III-1 to formula III-3:

[0019]

[0020] E1 is hydrogen, methyl, ethyl, vinyl, allyl, isopropyl, n-butyl, t-butyl, phenyl, benzyl, substituted phenyl, ethylene glycol methyl ether group, ethylene glycol ethyl ether group, polyethylene glycol methyl ether group, or polyethylene glycol ethyl ether group.

[0021] The application provides a method for catalyzing controllable polymerization of renewable vinyl monomers, comprising the following steps:

[0022] The addition polymerization reaction is performed by using the renewable vinyl monomers as monomers and a B / P organic Lewis acid-base pair as a catalyst.

[0023] The B / P organic Lewis acid-base pair is the above-mentioned B / P organic Lewis acid-base pair.

[0024] Preferably, the renewable vinyl monomers have the structure shown in any one of formula III-1 to formula III-3.

[0025]

[0026] E1 is hydrogen, methyl, ethyl, vinyl, allyl, isopropyl, n-butyl, t-butyl, phenyl, benzyl, substituted phenyl, ethylene glycol methyl ether group, ethylene glycol ethyl ether group, polyethylene glycol methyl ether group, or polyethylene glycol ethyl ether group.

[0027] Preferably, the molar ratio of the renewable vinyl monomers to the organic boron Lewis acid and the organic phosphorus Lewis base is 25-10000:1-100:1.

[0028] Preferably, the temperature of the addition polymerization reaction is -78°C to room temperature, and the reaction time is 10 seconds to 72 hours.

[0029] Preferably, the addition polymerization is performed under the condition of an organic solvent or without a solvent.

[0030] Preferably, the organic solvent is one or more of toluene, dichloromethane, 1.4-dioxane, fluorobenzene, chlorobenzene, tetrahydrofuran, and N,N-dimethylformamide.

[0031] The application provides a B / P organic Lewis acid-base pair for catalyzing active polymerization of renewable vinyl monomers, comprising an organic boron Lewis acid and an organic phosphine Lewis base.

[0032] Meanwhile, the B / P organic Lewis acid-base pair catalyst provided by the application is simple to synthesize and easy to commercialize, and has rich structure adjustability.

[0033] The application provides a method for catalyzing active and controllable polymerization of renewable vinyl monomers, comprising the following steps: using renewable vinyl monomers as monomers and using the B / P organic Lewis acid-base pair as a catalyst to perform an addition polymerization reaction. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a synthesis route of the organic boron Lewis acid LA18;

[0035] Figure 2 is a hydrogen spectrum of the organic boron Lewis acid LA18;

[0036] Figure 3 is a fluorine spectrum of the organic boron Lewis acid LA18;

[0037] Figure 4 is a synthesis route of the organic phosphine Lewis base LB13;

[0038] Figure 5 is a hydrogen spectrum of the organic phosphine Lewis base LB13;

[0039] Figure 6 is a phosphorus spectrum of the organic phosphine Lewis base LB13;

[0040] Figure 7is a GPC overlay plot of the polymers from Table 1 of Example 1 catalyzed by Phos2 / B(C6F5)3 of MMBL;

[0041] Figure 8 is a plot of the linear relationship between the molecular weight of the polymers from Table 1 of Example 1 catalyzed by Phos2 / B(C6F5)3 of MMBL and [MMBL]0 / [Phos2]0;

[0042] Figure 9 is a gel permeation chromatogram of the chain extension experiment of Example 2;

[0043] Figure 10 is a gel permeation chromatogram of the random copolymerization experiment of Example 3;

[0044] Figure 11 is a gel permeation chromatogram of the triblock copolymerization experiment of Example 3;

[0045] Figure 12 is a differential scanning calorimetry (DSC) plot of the copolymer of Example 3;

[0046] Figure 13 is a GPC overlay plot of the polymers from Table 4 of Example 4 catalyzed by Phos2 / B(C6F5)3 of MMBL;

[0047] Figure 14 is a plot of the linear relationship between the molecular weight (Mn) of the polymers from Table 4 of Example 4 catalyzed by Phos2 / B(C6F5)3 of 800 equivalents of MMBL and conversion (η) and polydispersity index (PDI). n DETAILED DESCRIPTION

[0048] The present application provides a B / P organic Lewis acid-base pair for catalyzing the living polymerization of renewable vinyl monomers, comprising an organic boron Lewis acid and an organic phosphorus Lewis base; the organic boron Lewis acid has a structure shown in any one of formula I-1 to formula I-11:

[0049]

[0050]

[0051] In formula I-1 to formula I-11, R1 is halogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl, pentafluorophenyl, trifluoromethyl, trimethylsilyl, or tetraphenylvinyl;

[0052] R2 is hydrogen, halogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, pentafluorophenyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl, trifluoromethyl, or trimethylsilyl; ​

[0053] R3 is hydrogen, halogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, pentafluorophenyl, trifluoromethyl or trimethylsilyl.

[0054] In the present application, the specific structure of the organic boron Lewis acid is preferably represented by formula LA1-LA20:

[0055]

[0056] In the present application, the source of the organic boron Lewis acid is commercially available or designed to be synthesized.

[0057] For example, the synthetic route of LA18 is shown in the following scheme: Figure 1 The hydrogen spectrum of LA18 is shown in the following figure: Figure 2 The fluorine spectrum is shown in the following figure: Figure 3

[0058] In the present application, the organic boron Lewis acid is preferably an organic borane compound substituted with a pentafluorophenyl group, and has the following structure:

[0059]

[0060] wherein R1 and R2 are pentafluorophenyl groups.

[0061] In the present application, the organic phosphine Lewis base has any one of the structures represented by formula II-1 to formula II-3:

[0062]

[0063] In formula II-1 to formula II-3, A1 is a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a tert-butyl group, a phenyl group, a substituted phenyl group, a vinyl group, an allyl group or an alkenyl group;

[0064] A2 is a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a tert-butyl group, a phenyl group, a substituted phenyl group, a vinyl group, an allyl group or an alkenyl group;

[0065] A3 is hydrogen, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a phenyl group, a substituted phenyl group, a pentafluorophenyl group, a trifluoromethyl group, a vinyl group, an allyl group or an alkenyl group.

[0066] In the present application, the organic phosphine Lewis base is preferably a guanidino-substituted and phosphorus ylide-substituted organic phosphine compound, and has any one of the structures represented by formula II-2 to formula II-3:

[0067]

[0068] ​In formula II-1 to formula II-3, A1 is preferably methyl or phenyl, A2 is preferably methyl or isopropyl, and A3 is preferably methyl or n-butyl.

[0069] In the present application, the specific structure of the organic phosphine Lewis base is preferably as follows:

[0070]

[0071]

[0072] In the present application, the source of the organic phosphine Lewis base is commercially available or designed for synthesis.

[0073] Taking LB13 as an example, the synthesis route of the organic phosphine Lewis base is as shown in Figure 4 The hydrogen spectrum of the organic phosphine Lewis base LB13 is as shown in Figure 5 The phosphorus spectrum is as shown in Figure 6

[0074] In the present application, the molar ratio of the organic boron Lewis acid and the organic phosphine Lewis base is preferably 1 to 100:1, more preferably 2 to 50:1, and further preferably 10 to 30:1.

[0075] The present application provides an application of the above-mentioned B / P organic Lewis acid-base pair in catalyzing the active polymerization of renewable vinyl monomers.

[0076] In the present application, the renewable vinyl monomer preferably has a structure as shown in any one of formula III-1 to formula III-3:

[0077]

[0078] In formula III-1 to formula III-3, E1 is hydrogen, methyl, ethyl, vinyl, allyl, isopropyl, n-butyl, t-butyl, phenyl, benzyl, substituted phenyl, ethylene glycol methyl ether group, ethylene glycol ethyl ether group, polyethylene glycol methyl ether group, or polyethylene glycol ethyl ether group.

[0079] In the present application, the renewable vinyl monomer is preferably a cyclic renewable vinyl monomer, and the structural formula is as follows:

[0080]

[0081] The present application provides a method for catalyzing the active and controllable polymerization of renewable vinyl monomers, comprising the following steps:

[0082] The addition polymerization reaction is carried out by taking the renewable vinyl monomer as a monomer and the B / P organic Lewis acid-base pair as a catalyst.

[0083] ​The B / P organic Lewis acid-base pair is the above-mentioned B / P organic Lewis acid-base pair.

[0084] In the present application, the renewable vinyl monomer has a structure shown in any one of formula III-1 to formula III-3:

[0085]

[0086] In formula III-1 to formula III-3, E1 is hydrogen, methyl, ethyl, vinyl, allyl, isopropyl, n-butyl, t-butyl, phenyl, benzyl, substituted phenyl, ethylene glycol methyl ether group, ethylene glycol ethyl ether group, polyethylene glycol methyl ether group or polyethylene glycol ethyl ether group. In the present application, the molar ratio of the renewable vinyl monomer to the organic boron Lewis acid and the organic phosphine Lewis base is preferably 25 to 10000:1 to 100:1, more preferably 50 to 8000:1 to 100:1, further preferably 100 to 5000:2 to 50:1, and more further preferably 500 to 2000:10 to 30:1.

[0087] In the present application, the addition polymerization has two feeding modes: one is that the Lewis acid is mixed with the monomer in advance and then the Lewis base is added; the other is that the Lewis base is mixed with the monomer in advance and then the Lewis acid is added.

[0088] In the present application, the addition polymerization is carried out in an organic solvent or without a solvent. That is, the addition polymerization reaction can be bulk polymerization or use an organic solvent as a polymerization medium.

[0089] In the present application, when an organic solvent is used as a polymerization medium, the organic solvent is one or several of toluene, dichloromethane, 1.4-dioxane, fluorobenzene, chlorobenzene, tetrahydrofuran and N,N-dimethylformamide. In the present application, the amount of the organic solvent is preferably such that the concentration of the monomer is 0.1 to 10 mol / L, and more preferably 1 to 5 mol / L.

[0090] In the present application, the temperature of the addition polymerization reaction is -78°C to room temperature, and the reaction time is 10 seconds to 72 hours.

[0091] The B / P organic Lewis acid-base pair for catalyzing the active polymerization of the renewable vinyl monomer and the catalytic polymerization method thereof provided in the present application are described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the present application.

[0092] In the present application, the structures and numbers of the Lewis bases and the renewable vinyl monomers used in the examples are shown as follows:

[0093]

[0094] Example 1 Catalytic polymerization of renewable monomer MMBL based on organic B / P Lewis base pair

[0095] The polymerization was carried out in a glove box. MMBL (1 mL, 9.4 mmol) was weighed into a 30 mL reaction vial with an appropriate amount of solvent (total solution volume was 10 mL). The Lewis base and Lewis acid were added, respectively, and the timer was started. After the monomer was completely converted, the reaction vial was taken out of the glove box, and the polymerization was terminated by adding 5% HC1 / methanol solution. The polymer was filtered and washed with methanol thoroughly, and dried under vacuum at 50 °C to constant weight. The molecular weight and molecular weight distribution of the obtained polymer were measured by gel permeation chromatography.

[0096] The results of catalytic polymerization using different organic B / P Lewis base pairs and different reaction conditions are summarized in Table 1. In the table, the molar ratio of Lewis acid: Lewis base = 2: 1. The GPC overlay of the polymers obtained from different ratios of monomers catalyzed by B(C6F5)3 / Phos2 is shown in Figure 7 , and the linear relationship between the molecular weight of the obtained polymer and [MMBL]0 / [Phos2]0 is shown in Figure 8 .

[0097] Table 1 Summary of catalytic polymerization of MMBL using different organic B / P Lewis base pairs

[0098]

[0099]

[0100]

[0101] Example 2 Chain extension of MMBL

[0102] The polymerization was carried out in a glove box. 12.0 mg of B(C6F5)3 was weighed into a 30 mL reaction vial, and MMBL (1 mL, 9.4 mmol) was added. After the monomer and Lewis acid were fully reacted, an appropriate amount of solvent (total solution volume was 10 mL) was added, and 3.8 mg of Phos2 was added, and the timer was started. After the monomer was completely converted, the same amount of MMBL (1 mL, 9.4 mmol) was added, and the process was repeated several times. After all the monomers were completely converted, the reaction vial was taken out of the glove box, and the polymerization was terminated by adding 5% HC1 / methanol solution. The polymer was filtered and washed with methanol thoroughly, and dried under vacuum at 60 °C to constant weight. The molecular weight and molecular weight distribution of the obtained polymer were measured by gel permeation chromatography.

[0103] The results of chain extension experiments using Phos2 with B(C6F5)3 system are summarized in Table 2. See Figure 9 This ideal chain extension experiment indicates that the catalytic polymerization system can achieve good activity retention at the end of polymer chains.

[0104] Table 2 Chain extension experiment results of MMBL polymerization

[0105] Feeding times Monomer 1 / Monomer 2 / Monomer 3 / Monomer 4 Conversion rate (%) Mn(10 3 g / mol) PDI Once 200 MMBL 100 26.2 1.05 Twice 200 / 200 MMBL 100 45.3 1.07 Thrice 200 / 200 / 200 MMBL 100 73.2 1.08

[0106] Copolymerization of γ-methyl-α-methylene-γ-butyrolactone (MMBL) and α-methylene-γ-butyrolactone (MBL)

[0107] For example, to prepare poly(PMMBL-block-PMBL-block-PMMBL): The polymerization was carried out in a glove box. 6.0 mg of Lewis acid was weighed into a 20 mL reaction vial. MMBL (0.5 mL, 4.7 mmol) was added. After the monomer and Lewis acid were well mixed, an appropriate amount of solvent (total volume of solution was 5 mL) was added. 1.9 mg of Phos2 was added and the timer was started. After the monomer was completely converted, MBL (0.48 mL, 4.7 mmol) was added. After the monomer was completely converted, an appropriate amount of MMBL (0.5 mL, 4.7 mmol) was added. After all the monomers were completely converted, the reaction vial was taken out of the glove box and the polymerization was terminated by adding 5% HC1 / methanol solution. The polymer was filtered and washed with methanol thoroughly. The polymer was dried in a vacuum oven at 60 °C to constant weight. The molecular weight and molecular weight distribution of the polymer were measured by gel permeation chromatography. See Figure 10 、 Figure 11 DSC was also used to further prove the perfect synthesis of the copolymer. See Figure 12 .

[0108] Table 3 Copolymerization of MMBL and MBL

[0109]

[0110] a Random copolymerization: both monomers were added at the same time.

[0111] Example 4 Molecular weight and molecular weight distribution of polymers obtained from 800 equivalents of MMBL catalyzed by Phos2 / B(C6F5)3 at different conversion

[0112] The polymerization was carried out in a glove box. MMBL (0.5 mL, 4.7 mmol) was weighed into a 30 mL reaction vial with an appropriate amount of dichloromethane (total solution volume was 10 mL). The Lewis acid (6.0 mg) and the Lewis base (1.9 mg) were added sequentially and the timer was started. Five sequential samples were taken over 2 minutes. Each sample was tested by NMR for monomer conversion, and then each sample was tested by GPC for molecular weight and molecular weight distribution. The results of the polymerization are shown in Table 4, and the GPC results are shown in Figure 13 . The plots of conversion versus molecular weight and molecular weight distribution are shown in Figure 14 .

[0113] Table 4 Phos2 / B(C6F5)3 catalyzed 800 equivalents of MMBL with sequential sampling

[0114]

[0115] Example 5

[0116] The polymerization of different renewable monomers catalyzed by different organic B / P Lewis acid-base pairs was carried out in a glove box. Different renewable monomers (0.5 mL to 1.0 mL) were weighed into a 20 mL reaction vial with an appropriate amount of dichloromethane or toluene (total solution volume was 5 mL). The Lewis base and the Lewis acid were added in a certain ratio, and the timer was started. After stirring for a period of time until the monomer was completely converted, the reaction vial was removed from the glove box, and 5% HCl / methanol solution was added to terminate the polymerization. The polymer was filtered off, washed thoroughly with methanol, and dried under vacuum at 50°C until a constant weight was obtained. The molecular weight and the molecular weight distribution of the obtained polymer were measured by gel permeation chromatography. The results of the polymerization of different renewable monomers catalyzed by different organic B / P Lewis acid-base pairs are summarized in Table 5.

[0117] Table 5 Summary of polymerization of different renewable monomers catalyzed by different organic B / P Lewis acid-base pairs

[0118]

[0119]

[0120] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for the catalytic, living, and controlled polymerization of renewable vinyl monomers, comprising the following steps: An addition polymerization reaction is carried out using renewable vinyl monomers as monomers and B / P organic Lewis acid-base pairs as catalysts; the molar ratio of the renewable vinyl monomers to organoboron Lewis acids and organophosphine Lewis bases is 500~2000:10~30:1, 200:1:1, 200:2:1, 400:2:1, 800:2:1 or 1600:2:

1. The renewable vinyl monomer has the structure shown in any one of Formula III-1 to Formula III-3: Formula III-1; Formula III-2; Formula III-3; In Formulas III-1 to III-3, E1 is hydrogen, methyl, ethyl, vinyl, allyl, isopropyl, n-butyl, tert-butyl, phenyl, benzyl, substituted phenyl, ethylene glycol methyl ether, ethylene glycol ethyl ether, polyethylene glycol methyl ether, or polyethylene glycol ethyl ether. The B / P organic Lewis acid-base pair includes an organoboron Lewis acid and an organophosphorus Lewis base. The organophosphorus Lewis base has any of the following structures: The organoboron Lewis acid has any of the following structures: 。 2. The method according to claim 1, characterized in that, The addition polymerization reaction is carried out at a temperature of -78°C to room temperature, and the reaction time is from 10 seconds to 72 hours.

3. The method according to claim 1, characterized in that, The addition polymerization is carried out under conditions of organic solvent or solvent-free conditions.

4. The method according to claim 1, characterized in that, The organic solvent is one or more of toluene, dichloromethane, 1,4-dioxane, fluorobenzene, chlorobenzene, tetrahydrofuran, and N,N-dimethylformamide.

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