A method for preparing a polyether with controllable molecular weight and molecular weight distribution

Abstract

The present invention discloses a method for preparing a polyether with controllable molecular weight and molecular weight distribution, comprising the steps of: adding an epoxy monomer to a catalyst-initiator-chain transfer system containing a Lewis acid, a Lewis base, a hydroxyl compound, a halogenated carboxylic acid, and / or a halogenated carboxylic acid ester to carry out a ring-opening polymerization reaction, thereby obtaining a polyether with a desired molecular weight and molecular weight distribution. The present invention introduces a controllable chain transfer mechanism during the ring-opening polymerization of the epoxy monomer. By adjusting the ratio of each material and the reaction conditions, the relative rates of chain growth and chain transfer reaction are controlled, thereby achieving dual control of the molecular weight and molecular weight distribution of the epoxy polyether. The reagents used are simple in structure and easy to prepare, and the polymerization reaction and post-processing operations are simple and convenient, making the epoxy polyether suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a method for preparing polyether with controllable molecular weight and molecular weight distribution. Background Art

[0002] Molecular weight distribution is an inherent property of synthetic polymers and a key factor influencing their performance. Narrow molecular weight distribution has long been considered a superior property in many fields due to its more uniform polymer chain length. However, in recent years, numerous studies have demonstrated that polymers with broad molecular weight distributions possess unique performance advantages in mechanical (mechanics), microphase separation, self-assembly, and surface-interface interactions, and their research and application value are no less than those of their narrower counterparts. It is well known that discussing molecular weight distribution control and its impact without considering molecular weight control is meaningless; molecular weight control and molecular weight distribution control are equally important, and traditional living / controlled polymerization methods cannot achieve dual control of molecular weight and molecular weight distribution.

[0003] At present, there are three main methods for controlling molecular weight distribution: 1) Mixing several narrow-distribution polymers with the same basic structure and different molecular weights in a certain proportion to form a polymer with a wider distribution: This method belongs to the category of post-polymerization processing, with complicated steps, high time and economic costs, and the length of the polymer chain in the mixed product does not change continuously, which does not conform to the "wide distribution" in the usual sense; 2) In the classic active polymerization system, the initiator is added in a staged and programmed manner through methods such as stoichiometry and fluid diffusion. The initiator added first initiates the formation of longer polymer chains, and the initiator added later initiates the formation of shorter polymer chains (that is, the molecular weight distribution of the polymer is controlled by adjusting the addition method of the initiator): This method is mainly used for active anionic double bond addition polymerization, which requires precise metering and flow control equipment and continuous operation, and relies on tedious condition screening in the early stage (confirmation). 3) In active / controlled free radical polymerization systems, a reversible chain end activation-deactivation mechanism is introduced to control the molecular weight distribution by adjusting the relative rates of chain growth and inter-chain active exchange. The core lies in utilizing the coexistence of active chains and inactive / low-activity chains to achieve differentiation in the growth rates of polymer chains, and controlling the degree of unevenness of polymer chain length (i.e., molecular weight distribution) by regulating the rate ratio of active exchange (i.e., chain transfer) and chain growth between the two during the polymerization process. This method usually only requires one step, with simple steps, a wide range of molecular weight distribution control, and high flexibility. However, current related research focuses on free radical polymerization, with limited monomer and polymer types, and the realization of reversible chain deactivation / deactivation processes often requires the use of chain transfer agents, catalysts, or additives with more complex structures.

[0004] Aliphatic polyethers obtained through the ring-opening polymerization of epoxy monomers come in a wide variety of types and properties, holding an irreplaceable position in numerous fields. Therefore, the potential impact of molecular weight distribution on the properties of polyethers and related materials is self-evident. (For example, in the preparation of styrene-polyethylene glycol-styrene triblock polymers, using a broad-distribution polyethylene glycol obtained by end-group coupling-step polymerization as the middle block can achieve higher ion mobility than using conventional narrow-distribution polyethylene glycol.) However, currently commercialized polyethers (particularly polyethylene oxide / polyethylene glycol and polypropylene oxide / polypropylene glycol) are mostly narrow-distribution products. Even if some products have a broad molecular weight distribution, this is due to uncontrollable ring-opening polymerization or insufficient chemical selectivity. A ring-opening polymerization method that can truly achieve dual control of both molecular weight and molecular weight distribution of polyethers has yet to be established.

[0005] Therefore, it is of great significance to develop a method for preparing polyether with controllable molecular weight and molecular weight distribution. Summary of the Invention

[0006] The object of the present invention is to provide a method for preparing polyether with controllable molecular weight and molecular weight distribution.

[0007] The technical solution adopted by the present invention is:

[0008] A method for preparing a polyether with controllable molecular weight and molecular weight distribution comprises the following steps: adding an epoxy monomer to a catalysis-initiation-chain transfer system containing a Lewis acid, a Lewis base, a hydroxyl compound, a halogenated carboxylic acid and / or a halogenated carboxylic acid ester to carry out a ring-opening polymerization reaction, thereby obtaining a polyether with a desired molecular weight and molecular weight distribution.

[0009] Preferably, the ratio of the total molar amount of the hydroxyl compound to the halogenated carboxylic acid and / or halogenated carboxylic acid ester, the molar amount of the epoxy monomer, the molar amount of the Lewis acid, and the molar amount of the Lewis base is 1:5-10000:0.001-10:0-20.

[0010] More preferably, the ratio of the total molar amount of the hydroxyl compound to the halogenated carboxylic acid and / or halogenated carboxylic acid ester, the molar amount of the epoxy monomer, the molar amount of the Lewis acid, and the molar amount of the Lewis base is 1:45-1600:0.1-1:0.05-2.

[0011] Preferably, the epoxy monomer is ethylene oxide, C1-C 20 Linear alkyl substituted ethylene oxide, C1~C 16 Straight chain alkyl glycidyl ether, isopropyl glycidyl ether, tert-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, allyl glycidyl ether, propargyl glycidyl ether, glycidyl methacrylate, glycidyl acrylate, C1~C 12At least one of the linear fatty carboxylic acid glycidyl esters, having the following structural formula:

[0012]

[0013] Preferably, the Lewis acid is at least one of trialkylborane, dialkylalkoxyborane, urea, and thiourea.

[0014] More preferably, the Lewis acid is tri-sec-butylborane ( s Bu3B), triisopropylborane ( i At least one of Pr3B), tristraight-chain alkylborane (A3B), dialkylalkoxyborane (ADAB), urea (Urea), and thiourea (Thiourea), with the following structural formula:

[0015]

[0016] Preferably, the Lewis base is at least one of a tertiary amine, amidine, guanidine, nitrogen heterocyclic carbene, triaminophosphine, phosphazene base, quaternary ammonium base, quaternary ammonium halide, quaternary ammonium carboxylate, alkali metal tert-butoxide, and alkali metal pivalate.

[0017] More preferably, the Lewis base is DABCO, PMDETA, ME6TREN, sparteine, DBN, DBU, MTBD, TMG, PMG, HMTP, HETP, TMAP, TIPAP, BEMP, t BuP1, t BuP2, EtP2, t BuP4, alkali metal salts, PAS, t At least one of BuOM, QAB, and QAS, with the following structural formula:

[0018]

[0019] Preferably, the hydroxy compound is C1 to C 18 Primary alcohols, C3~C 18 Secondary alcohols, C4~C 18 Tertiary alcohols, phenols, 1-phenyl linear alkyl alcohols with 1 to 10 saturated carbon atoms, C1 to C 16 Alkyl substituted phenol, allyl alcohol, saturated carbon number 2 to 10 straight chain terminal olefin 1-alcohol, 2-(allyloxy)ethanol, propargyl alcohol, cholesterol, terephthalic acid, C2 to C 18At least one of n-alkyl glycol, glycerol, pentaerythritol, dipentaerythritol, tripentaerythritol, polyvinyl alcohol, polyglycidol, polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate, poly(p-hydroxystyrene), poly(p-hydroxymethylstyrene), polystyrene-b-polyethylene oxide, hydroxyl-containing polylactone, and hydroxyl-containing polyether.

[0020] More preferably, the hydroxy compound is at least one of the compounds represented by formula (1) to formula (24):

[0021]

[0022] Preferably, the halogenated carboxylic acid is at least one of the following compounds:

[0023] Preferably, the halogenated carboxylic acid ester is at least one of the following compounds:

[0024]

[0025] Preferably, the ring-opening polymerization reaction is carried out at -50°C to 150°C, and the reaction time is 0.1h to 240h.

[0026] Preferably, the ring-opening polymerization reaction is carried out in a protective atmosphere.

[0027] Preferably, the protective atmosphere is a nitrogen atmosphere or an argon atmosphere.

[0028] Preferably, the ring-opening polymerization reaction is carried out in a solvent system.

[0029] Preferably, the solvent is at least one of benzene, toluene, tetrahydrofuran, 1,4-dioxane, 2-methyltetrahydrofuran, acetone, and ethyl acetate.

[0030] The beneficial effects of the present invention are as follows: the present invention introduces a controllable chain transfer mechanism during the ring-opening polymerization of epoxy monomers, and by adjusting the proportions of various materials and reaction conditions, the relative rates of chain growth and chain transfer reactions are controlled, thereby achieving dual control of the molecular weight and molecular weight distribution of the epoxy polyether. Furthermore, the reagents used are simple in structure and easy to prepare (most of them are commercial products), and the polymerization reaction and post-processing operations are simple and convenient, making the present invention suitable for large-scale industrial production applications.

[0031] Specifically:

[0032] 1) The present invention introduces a controllable chain transfer mechanism during the ring-opening polymerization of epoxy monomers. By controlling the relationship between the rates of chain transfer and chain growth, the synthesis of polymers with a clear molecular structure and dual controllable molecular weight and molecular weight distribution is achieved;

[0033] 2) The present invention does not require the synthesis of a large amount of sample for mixing, and only requires a one-step reaction, which is time-saving and cost-effective. In addition, the chain length of the polymer in the product changes continuously, which conforms to the "broad distribution" in the usual sense.

[0034] 3) The present invention does not rely on complex reaction equipment and precise stoichiometry, can easily achieve 100% initiation efficiency and realize dual control of molecular weight and molecular weight distribution, and the preliminary condition screening process is simple, which is conducive to large-scale application;

[0035] 4) The chain transfer agent (halogenated carboxylic acid / halogenated carboxylic acid ester) of the present invention has a simple structure, is easy to prepare (or is a cheap commercial product), and has good chemical stability;

[0036] 5) The present invention cleverly utilizes the high selectivity and easily adjustable catalytic activity of the Lewis acid-base pair of the catalyst, especially the difference in catalytic activity for the ring-opening polymerization of epoxy monomers and end-group transesterification. By simply changing the material ratio and reaction conditions of the polymerization reaction (for example, the ratio of chain transfer agent to initiator, the ratio of Lewis acid to Lewis base, monomer concentration, temperature, etc.), the molecular weight (400 to 2,000,000) and molecular weight distribution of the product (polyether) can be achieved. The dual control is simpler than the existing method, and the regulation mechanism is richer and more flexible;

[0037] 6) The catalytic system used in the present invention has extremely high chemoselectivity for the ring-opening polymerization of epoxy monomers. Pendant functional groups (epoxy substituents) are widely tolerated in this system, so it is universal for most commercial or easily prepared epoxy monomers;

[0038] 7) The chain transfer agent used in the present invention belongs to the category of active esters and can be removed by simple post-treatment methods (e.g., in-situ alcoholysis, aminolysis, etc.) after polymerization, thereby facilitating the uniformity of the polymer end group structure;

[0039] 8) The present invention can obtain non-linear polymer structures such as star-shaped and grafted structures with controllable molecular weight distribution of arms or side chains through the combined use of small molecule or polymer polyhydroxy compounds (multifunctional initiators) and their partially halogenated carboxylic acid esterification products (chain transfer agents). Based on the dual control of molecular weight and molecular weight distribution, the side groups, end groups, topological structures and corresponding properties of the polyether can be flexibly designed and regulated;

[0040] 9) The method of the present invention, combined with the use of a macromolecular initiator, or by staged, in-situ regulation of catalytic activity during the continuous polymerization of two or more monomers, can synthesize (multi-)block polymers with controllable molecular weight and block ratio and differentially adjustable block molecular weight distribution (which is difficult to achieve with current synthesis methods), providing a new strategy for enriching and regulating the properties of block copolymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 SEC charts of polyethylene glycol monomethyl ether of Examples 1 to 4.

[0042] Figure 2 SEC charts of polypropylene oxide monomethyl ether of Examples 15 to 18. DETAILED DESCRIPTION

[0043] The present invention will be further explained and illustrated below with reference to specific embodiments.

[0044] Monomer conversion and polymer structural characteristics were measured using a Bruker AV400 liquid nuclear magnetic resonance spectrometer in deuterated chloroform.

[0045] Molecular weight and molecular weight distribution The test was performed using an Agilent 1260 Infinity size exclusion chromatograph with tetrahydrofuran as the mobile phase, a column temperature of 35°C, and a flow rate of 1 mL / min. A series of polystyrene or polyethylene oxide standard samples were used to make calibration curves. Polymers other than polyethylene oxide (polyethylene glycol) were measured using polystyrene calibration curves.

[0046] The amounts of raw materials added in Examples 1 to 22 are all in molar fractions.

[0047] Example 1:

[0048] A polyethylene glycol monomethyl ether ( The preparation method of the invention comprises the following steps:

[0049] In a nitrogen atmosphere, 0.25 parts of methanol, 0.75 parts of methyl trifluoroacetate, 0.05 parts of phosphazene base t BuP2, 0.1 parts of tributyl boron and an appropriate amount of tetrahydrofuran (THF) were added to a dry glass reactor in sequence and stirred evenly. The reactor was then connected to a vacuum line, some of the gas in the reactor was removed, and the temperature was lowered with ice ethanol. 160 parts of ethylene oxide (EO, [EO]0 = 10.0 mol / L) was then added at -50°C. The glass reactor was sealed and reacted at 0°C for 2 hours. The reaction bottle was then opened, methanol was added to dissolve the mixture, and the mixture was heated and stirred at 60°C for 12 hours to obtain a crude product ( 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.5 kg / mol as measured by SEC. ), and then the crude product was precipitated in ether, the white powder was collected and dried in vacuo to obtain polyethylene glycol monomethyl ether.

[0050] Methanol, methyl trifluoroacetate, THF, and EO were all purified and dehydrated before use.

[0051] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0052] Results test:

[0053] SEC (size exclusion chromatography) measured the number average molecular weight of polyethylene glycol monomethyl ether to be 7.5 kg / mol. (SEC Figure Figure 1 As shown, wherein CIR = [halogenated carboxylic acid ester] / [hydroxy compound]).

[0054] The NMR data of polyethylene glycol monomethyl ether are as follows:

[0055] 1 H NMR (400MHz, CDCl3): δ / ppm=3.82-3.45(-OCH2CH2O-), 3.74-3.71(-OCH2CH2OH), 3.37-3.35(-OCH3). M n,NMR =7.9kg / mol.

[0056] Example 2:

[0057] A polyethylene glycol monomethyl ether ( The preparation method of the product with a degree of polymerization of 160 is the same as that of Example 1 except that the ratio of methanol to methyl trifluoroacetate is changed (1 part of methanol is added and methyl trifluoroacetate is not added).

[0058] The molar ratio of the hydroxyl compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 1:0:0.05:0.1.

[0059] Results test:

[0060] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.5 kg / mol as measured by SEC.

[0061] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.5 kg / mol. (SEC Figure Figure 1 shown).

[0062] Example 3:

[0063] A polyethylene glycol monomethyl ether ( The preparation method of the invention is the same as that of Example 1 except that the ratio of methanol to methyl trifluoroacetate is changed (0.75 parts of methanol and 0.25 parts of methyl trifluoroacetate are added).

[0064] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.75:0.25:0.05:0.1.

[0065] Results test:

[0066] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 8.1 kg / mol as measured by SEC.

[0067] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 8.2 kg / mol. (SEC Figure Figure 1 shown).

[0068] Example 4:

[0069] A polyethylene glycol monomethyl ether ( The preparation method of the invention is the same as that of Example 1 except that the ratio of methanol to methyl trifluoroacetate is changed (0.5 parts of methanol and 0.5 parts of methyl trifluoroacetate are added).

[0070] In the catalysis-initiation-chain transfer system of this embodiment, the molar ratio of the hydroxyl compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid is 0.5:0.5:0.05:0.1.

[0071] Results test:

[0072] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.3 kg / mol as measured by SEC.

[0073] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.3 kg / mol. (SEC Figure Figure 1 shown).

[0074] Example 5:

[0075] A polyethylene glycol monomethyl ether ( In the range of 1.10 to 1.20, the degree of polymerization is 160) preparation method, except changing the ratio of Lewis acid-base pair (adding 0.09 parts of tExcept for BuP2 and 0.1 parts of tributyl boron, the rest is the same as in Example 1.

[0076] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.09:0.1.

[0077] Results test:

[0078] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.2 kg / mol as measured by SEC.

[0079] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.2 kg / mol. Example 6:

[0080] A polyethylene glycol monomethyl ether ( The preparation method of the present invention (with a degree of polymerization of 160 and a range of 1.40 to 1.50) is the same as that of Example 1 except that the concentration of the EO polymerization reaction is adjusted to 3 mol / L.

[0081] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0082] Results test:

[0083] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.2 kg / mol as measured by SEC.

[0084] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.2 kg / mol. Example 7:

[0085] A polyethylene glycol monoethyl ether ( The preparation method of the invention (with a polymerization degree of 160 and a range of 1.60 to 1.70) is the same as that of Example 1 except that the hydroxy compound is replaced by ethanol and the halogenated carboxylic acid (ester) is replaced by ethyl trifluoroacetate.

[0086] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0087] Results test:

[0088] 1The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.1 kg / mol as measured by SEC.

[0089] The number average molecular weight of polyethylene glycol monoethyl ether measured by SEC was 7.2 kg / mol. Example 8:

[0090] A polyethylene glycol ( The preparation method of the invention is the same as that of Example 1 except that the hydroxy compound is changed to ethylene glycol and the halogenated carboxylic acid (ester) is changed to ethylene glycol ditrifluoroacetate.

[0091] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0092] Results test:

[0093] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.2 kg / mol as measured by SEC.

[0094] The number average molecular weight of polyethylene glycol measured by SEC was 7.3 kg / mol. Example 9:

[0095] A four-arm polyethylene glycol ( The preparation method of the present invention is the same as that of Example 1, except that the hydroxy compound is changed to pentaerythritol, the halogenated carboxylic acid (ester) is changed to pentaerythritol tetrakis trifluoroacetate, and the amount of tributyl boron is changed to 0.2 parts.

[0096] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.2.

[0097] Results test:

[0098] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 6.5 kg / mol as measured by SEC.

[0099] The number average molecular weight of four-arm polyethylene glycol was 6.6 kg / mol as measured by SEC. Example 10:

[0100] A polyethylene glycol monomethyl ether ( The preparation method of the polymerization degree of 45 (within the range of 1.60 to 1.70) is the same as that of Example 1 except that the amount of ethylene oxide added is changed to 45 parts.

[0101] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0102] Results test:

[0103] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 2.0 kg / mol as measured by SEC.

[0104] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 2.1 kg / mol. Example 11:

[0105] A polyethylene glycol monomethyl ether ( The preparation method of the invention (with a degree of polymerization of 400 and a range of 1.55 to 1.65) is the same as that of Example 1 except that the amount of ethylene oxide added is changed to 400 parts.

[0106] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0107] Results test:

[0108] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 17.9 kg / mol as measured by SEC.

[0109] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 18.3 kg / mol. Example 12:

[0110] A polyethylene glycol monomethyl ether ( The preparation method of the invention is the same as that of Example 1 except that the Lewis base is changed to triethylamine.

[0111] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0112] Results test:

[0113] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.1 kg / mol as measured by SEC.

[0114] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.1 kg / mol. Example 13:

[0115] A polyethylene glycol monomethyl ether ( The preparation method of the invention is the same as that of Example 1 except that the Lewis base is changed to the tertiary amine DABCO.

[0116] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0117] Results test:

[0118] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.1 kg / mol as measured by SEC.

[0119] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.1 kg / mol. Example 14:

[0120] A polyethylene glycol monomethyl ether ( The preparation method of the invention is the same as that of Example 1 except that the Lewis acid is changed to triisopropylborane.

[0121] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0122] Results test:

[0123] 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.2 kg / mol as measured by SEC.

[0124] The number average molecular weight of polyethylene glycol monomethyl ether measured by SEC was 7.3 kg / mol. Example 15:

[0125] A polypropylene oxide monomethyl ether ( The preparation method of the invention comprises the following steps:

[0126] In a nitrogen atmosphere, 0.25 parts of methanol, 0.75 parts of methyl trifluoroacetate, 80 parts of propylene oxide (PO) and an appropriate amount of tetrahydrofuran (THF) were added to a dry glass reactor and stirred evenly, and then 0.05 parts of phosphazene base was added. t BuP2 and 0.1 parts of triethylborane ([PO]0=10.0mol / L), stirred at room temperature for 8h, and the crude product ( 1 The conversion rate of PO was 100% as measured by H NMR, and the number average molecular weight of the crude product was 6.8 kg / mol as measured by SEC. ), then open the reaction flask and add methanol and tetrahydrofuran, heat the reaction flask to 40°C and react for 12 hours. After removing the ester group, dilute the reaction solution with THF, add neutral alumina and anhydrous MgSO4 in sequence, stir, filter, collect the filtrate, and spin dry to obtain polypropylene oxide monomethyl ether.

[0127] Methanol, methyl trifluoroacetate, THF, and PO were all purified and dehydrated before use.

[0128] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0129] Results test:

[0130] The number average molecular weight of polypropylene oxide monomethyl ether measured by SEC was 6.7 kg / mol. (SEC Figure Figure 2 shown).

[0131] Example 16:

[0132] A polypropylene oxide monomethyl ether ( The preparation method of the present invention is the same as that of Example 15 except that the ratio of the hydroxyl compound and the halogenated carboxylic acid (ester) is changed (1 part of methanol is added and no halogenated carboxylic acid (ester) is added).

[0133] The molar ratio of the hydroxyl compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 1:0:0.05:0.1.

[0134] Results test:

[0135] 1 The PO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.6 kg / mol as measured by SEC.

[0136] The number average molecular weight of polypropylene oxide monomethyl ether measured by SEC was 7.6 kg / mol. (SEC Figure Figure 2 shown).

[0137] Example 17:

[0138] A polypropylene oxide monomethyl ether ( The preparation method of the present invention is the same as that of Example 15 except that the ratio of the hydroxyl compound and the halogenated carboxylic acid (ester) is changed (0.75 parts of methanol and 0.25 parts of methyl trifluoroacetate are added).

[0139] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.75:0.25:0.05:0.1.

[0140] Results test:

[0141] 1 The PO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.6 kg / mol as measured by SEC.

[0142] The number average molecular weight of polypropylene oxide monomethyl ether measured by SEC was 7.8 kg / mol. (SEC Figure Figure 2 shown).

[0143] Example 18:

[0144] A polypropylene oxide monomethyl ether ( The preparation method of the present invention is consistent with Example 15 except that the ratio of the hydroxyl compound and the halogenated carboxylic acid (ester) is changed (0.5 parts of methanol and 0.5 parts of methyl trifluoroacetate are added).

[0145] In the catalysis-initiation-chain transfer system of this embodiment, the molar ratio of the hydroxyl compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid is 0.5:0.5:0.05:0.1.

[0146] Results test:

[0147] 1 The PO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.0 kg / mol as measured by SEC.

[0148] The number average molecular weight of polypropylene oxide monomethyl ether measured by SEC was 6.7 kg / mol. (SEC Figure Figure 2 shown).

[0149] Example 19:

[0150] A polypropylene oxide monomethyl ether ( The preparation method of the invention (with a degree of polymerization of 80 and a range of 1.70 to 1.80) is the same as that of Example 15 except that the amount of Lewis acid is increased to 0.2 parts.

[0151] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.2.

[0152] Results test:

[0153] 1 The PO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.4 kg / mol as measured by SEC.

[0154] The number average molecular weight of polypropylene oxide monomethyl ether measured by SEC was 7.3 kg / mol. Example 20:

[0155] A polypropylene oxide monomethyl ether ( The preparation method of the invention (with a degree of polymerization of 400 and a range of 1.550 to 1.60) is the same as that of Example 15 except that the amount of monomer is changed to 400 parts.

[0156] The molar ratio of the hydroxy compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid in the catalysis-initiation-chain transfer system of this embodiment is 0.25:0.75:0.05:0.1.

[0157] Results test:

[0158] 1 The PO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 28.6 kg / mol as measured by SEC.

[0159] The number average molecular weight of polypropylene oxide monomethyl ether measured by SEC was 29.3 kg / mol. Example 21:

[0160] A methyl polyglycidyl butyl ether ( The preparation method of the invention comprises the following steps:

[0161] In a nitrogen atmosphere, 0.25 parts of methanol, 0.75 parts of methyl trifluoroacetate, and 60 parts of glycidyl butyl ether (BGE) were added to a dry glass reactor and stirred evenly, and then 0.2 parts of phosphazene base were added. t BuP2 and 0.4 parts of triethylborane were stirred at room temperature for 24 hours to obtain a crude product ( 1 The BGE conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 7.9 kg / mol as measured by SEC. ), then open the reaction flask and add methanol and tetrahydrofuran (THF), then heat the reaction flask to 40°C for 12 hours, remove the ester group and dilute the reaction solution with THF, add neutral alumina and anhydrous MgSO4 in sequence, stir, filter, collect the filtrate, and spin dry to obtain methyl polyglycidyl butyl ether.

[0162] Methanol, methyl trifluoroacetate, THF, and PO were purified and dehydrated before use.

[0163] In the catalysis-initiation-chain transfer system of this embodiment, the molar ratio of the hydroxyl compound, the halogenated carboxylic acid (ester), the Lewis base and the Lewis acid is 0.25:0.75:0.2:0.4.

[0164] Results test:

[0165] The number average molecular weight of methyl polyglycidyl butyl ether measured by SEC was 8.0 kg / mol.

[0166] Example 22:

[0167] A method for preparing a methylpolyethylene oxide-b-polypropylene oxide block copolymer (polyethylene oxide segment has a narrow distribution and polypropylene oxide segment has a wide distribution), comprising the following steps:

[0168] In a nitrogen atmosphere, 0.2 parts of methanol, 0.8 parts of methyl trifluoroacetate, 0.09 parts of phosphazene base t BuP2, 0.10 parts of triethylborane and an appropriate amount of THF were added to a dry glass reactor in sequence and stirred evenly. The reactor was then connected to a vacuum line to remove part of the gas in the bottle and cooled in an ice-water bath. 80 parts of EO ([EO]0 = 10.0 mol / L) were then added at -40°C. The sealed glass reactor was reacted at 0°C for 0.5 h. 1 The EO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 3.5 kg / mol as measured by SEC. ), then move the reaction bottle into the glove box, add 80 parts of PO, and additionally add 0.30 parts of triethylboron (a total of 0.40 parts), and then heat the reaction bottle until the reaction liquid is homogeneous. Slowly cool the reaction bottle to room temperature and continue stirring for 12 hours to obtain a crude product ( 1 The PO conversion rate was 100% as measured by H NMR, and the number average molecular weight of the crude product was 9.2 kg / mol as measured by SEC. ), then open the reaction flask and add methanol, heat to 40°C and react for 6 hours, remove the ester group and dilute the reaction solution with THF, add neutral alumina and anhydrous MgSO4 in sequence, stir, filter, collect the filtrate, and spin dry to obtain methyl polyethylene oxide-b-polypropylene oxide block copolymer.

[0169] Methyl trifluoroacetate, tetrahydrofuran (THF), EO, and PO were all purified and dehydrated before use.

[0170] Results test:

[0171] The number average molecular weight of the methylpolyethylene oxide-b-polypropylene oxide block copolymer was 9.4 kg / mol by SEC.

[0172] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a polyether with controllable molecular weight and molecular weight distribution, characterized in that: The following steps are involved: Adding epoxy monomers to a catalyst-initiator-chain transfer system containing Lewis acid, Lewis base, hydroxyl compound, halogenated carboxylic acid and / or halogenated carboxylic acid ester to carry out a ring-opening polymerization reaction to obtain a polyether with a desired molecular weight and molecular weight distribution; The ratio of the total molar amount of the hydroxyl compound to the halogenated carboxylic acid and / or halogenated carboxylic acid ester, the molar amount of the epoxy monomer, the molar amount of the Lewis acid, and the molar amount of the Lewis base is 1:45-1600:0.1-1:0.05-2; The Lewis acid is at least one of trialkylborane, dialkylalkoxyborane, urea, and thiourea; The Lewis base is at least one of a tertiary amine, amidine, guanidine, nitrogen heterocyclic carbene, triaminophosphine, phosphazene base, quaternary ammonium base, quaternary ammonium halide, quaternary ammonium carboxylate, alkali metal tert-butoxide, and alkali metal pivalate; The halogenated carboxylic acid is at least one of the following compounds: ； The halogenated carboxylic acid ester is at least one of the following compounds: 。 2. The preparation method according to claim 1, wherein: The epoxy monomer is ethylene oxide, C1~C 20 Linear alkyl substituted ethylene oxide, C1~C 16 Straight chain alkyl glycidyl ether, isopropyl glycidyl ether, tert-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, allyl glycidyl ether, propargyl glycidyl ether, glycidyl methacrylate, glycidyl acrylate, C1~C 12 At least one of the straight-chain fatty carboxylic acid glycidyl esters.

3. The preparation method according to claim 1, wherein: The hydroxy compound is C1~C 18 Primary alcohols, C3~C 18 Secondary alcohols, C4~C 18 Tertiary alcohols, phenols, C1~C 16 At least one of alkyl-substituted phenol, cholesterol, polyvinyl alcohol, polyglycidol, polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate, poly(p-hydroxystyrene), poly(p-hydroxymethylstyrene), polystyrene-b-polyethylene oxide, hydroxyl-containing polylactone, and hydroxyl-containing polyether.

4. The preparation method according to claim 1, wherein: The ring-opening polymerization reaction is carried out at -50°C to 150°C, and the reaction time is 0.1h to 240h.

5. The preparation method according to claim 4, characterized in that: The ring-opening polymerization reaction is carried out in a protective atmosphere.

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