CN115073724B - A kind of method of olefin and epoxide block copolymerization - Google Patents

Abstract

The invention discloses a block copolymerization method of olefin and epoxy oxide. The method comprises the following steps: in an inert atmosphere, anionic double bond addition polymerization of olefin is initiated by organolithium, and ethylene oxide is used for capping. Then, the active polyolefin capped with ethylene oxide is used as a macroinitiator, and a two-component organic/metal-free catalyst composed of an organic base and an alkyl boron is added to implement anionic ring-opening polymerization of epoxides to obtain polyolefin-polymer Ether block copolymers. The invention provides an in-situ active conversion strategy, which can realize the continuous block copolymerization of olefins and epoxides under mild conditions, and prepare polyolefins with flexible controllable molecular weight, block ratio and side group combination in one pot ‑Polyether block copolymers.

Description

A kind of method of olefin and epoxide block copolymerization

technical field

The invention belongs to the technical field of block copolymer synthesis, and in particular relates to a method for preparing a polyolefin-polyether block copolymer in one pot using an in-situ catalytic activity conversion strategy.

Background technique

Amphiphilic block copolymers refer to polymers in which there are covalently bonded solvophilic segments and solvophobic segments in the polymer structure (solvents generally refer to water), which can be used as emulsifiers, dispersants Agents, stabilizers, anti-forming agents, surface modifiers for plastics, and polymer blending compatibilizers have received extensive attention and research for decades. Polyethylene oxide (PEO) with both water solubility and biocompatibility as the hydrophilic segment, polybutadiene (PB), polyisoprene (PI) or polystyrene (PS), etc. Polyolefins are amphiphilic block copolymers constructed of hydrophobic segments, including PB-b-PEO, PI-b-PEO, PS-b-PEO, etc., because both epoxy monomers and olefin monomers have yields Large, cheap, wide sources and other advantages, and has significant basic and applied research value. In addition to PEO, block copolymers of aliphatic polyethers derived from other epoxides (such as propylene oxide, PO) and the above polyolefins also have similar amphiphilic properties.

The molecular weight, relative content and microstructure of solvophilic and solvophobic segments are the basic means to regulate the properties of amphiphilic block copolymers. Organolithium-initiated living anionic polymerization is the preferred method for the controlled synthesis of terminally active and monodisperse PB, PI, and PS segments. However, when these active polyolefin chains are used as macroinitiators to synthesize PB-b-PEO, PI-b-PEO, and PS-b-PEO, copolymers with expected block structures cannot be obtained. This is because PB-CH ₂ CH ₂ OLi, PI-CH ₂ CH ₂ OLi, and PS-CH ₂ CH ₂ OLi (alkoxylithium) generated after the reaction of ethylene oxide (EO) and carbanion have strong Anion-cation interactions and ion-pair associations lead to very low reactivity of oxyanions, which cannot continue to react with EO to polymerize them. In relatively early studies, a common approach to address this problem was to replace lithium ions with sodium or potassium ions that interact weakly with oxyanions. However, in this case, the polymerization reaction of EO needs to be carried out at high temperature for a long time to achieve a high conversion rate and form a block copolymer. Later, it was found that if the organic phosphazene superbase ^tBuP ₄ was added as a catalyst in the polymerization system, EO could successfully undergo ring-opening polymerization from the end of the polyolefin chain at room temperature to 50 °C. Among them, the role of ^tBuP ₄ is to complex with lithium ions to form [ ^tBuP ₄ Li] ⁺ , thereby increasing the size of counter ions, reducing the interaction between anions and cations and inhibiting the association of ion pairs, thereby increasing the concentration of oxyanions. active. However, it still takes 2 to 3 days for EO to be completely consumed. In 2010, some researchers found that _adding excess triisobutylaluminum instead of ^tBuP4 into the polymerization system can make EO reach a high conversion rate within a few hours at room temperature. They believe that an equal amount of triisobutylaluminum can react with the alkoxylithium at the end of the macroinitiator chain to form a lithium-aluminate complex, thereby inhibiting the aggregation of lithium salts and enhancing the nucleophilic effect of the chain end on EO. Offensive activity. The rest of triisobutylaluminum plays the role of activating EO and improving its ring-opening polymerization activity. The structures of the obtained PI-b-PEO and PS-b-PEO block copolymers are relatively controllable within the designed molecular weight of the PEO segment within 10kg/mol. However, due to the existence of chain transfer reactions in this system, the initiation efficiency of the active polyolefin macromolecules is about 80%, and additional separation and purification are required to obtain block copolymers with well-defined structures. In addition, when lithium alkoxide is used as the initiator, whether it is a non-nucleophilic organic strong base ^tBuP ₄ or triisobutylaluminum, it is often only suitable for the ring-opening polymerization of EO, but for monosubstituted epoxy monomers The catalytic effect of (such as PO) ring-opening polymerization is not satisfactory, and the chain transfer to the monosubstituted epoxy monomer makes it difficult for the molecular weight of the polyether segment to break through the limit of 5.0kg/mol under the premise of narrow dispersion.

In summary, how to make EO, PO and other epoxy monomers undergo efficient and controllable ring-opening polymerization under relatively mild conditions with macromolecular alkoxide lithium as the initiator is a one-pot method for the preparation of polymers by living anionic polymerization. The biggest problem facing olefin-polyether amphiphilic block copolymers.

Contents of the invention

In order to solve the shortcomings and deficiencies of the prior art, the object of the present invention is to provide a method for block copolymerization of olefins and epoxides, specifically a one-pot preparation of polyolefin-polyether using an in-situ catalytic activity conversion strategy block copolymer method.

The method is based on the initiating effect of alkoxylithium macroinitiator and the catalytic and controlling effect of organic/metal-free Lewis acid-base pair, so that the anionic double bond addition polymerization of olefin monomer initiated by organolithium and polyolefin macromolecule alkane Lithium oxide-initiated anionic ring-opening polymerization of epoxides was carried out continuously and controllably in the same reactor for one-pot synthesis of polyolefin-polyether block copolymers. The method has the advantages of wide sources of raw materials, mild reaction conditions, simple operation, flexible and precise control of the molecular weight and block ratio of the product (mainly amphiphilic block copolymer).

The object of the invention is achieved through the following technical solutions:

A method for block copolymerization of olefins and epoxides, comprising the steps of:

In an inert or nitrogen atmosphere, with olefins as monomers and organic lithium as initiators, carry out anionic polymerization of olefins in solution, and then add ethylene oxide to cap the polyolefins to obtain alkoxy groups at the end of the chain. The active polyolefin of lithium; the active polyolefin with alkoxylithium at the end of the chain is used as a macroinitiator, and an organic/metal-free Lewis acid-base pair catalyst composed of an epoxy monomer, an organic base and an alkyl boron is added to carry out Structure-controllable polyolefin-polyether block copolymer prepared by ring-opening polymerization in one pot.

Further, the olefin monomer is (1) butadiene, (2) isoprene, (3) styrene, (4) 2-methylstyrene, (5) 3-methylstyrene, At least one of (6) 4-methylstyrene, (7) 4-methoxystyrene, (8) 2,4-dimethylstyrene and (9) 2,5-dimethylstyrene .

Furthermore, the olefin monomer is at least one of isoprene, butadiene and styrene.

Further, the organolithium initiator is R-Li, R is one of an alkyl group, a cycloalkyl group or an aryl group with 1 to 14 carbon atoms, and Li is a lithium atom. Preference is given to n-butyllithium and/or sec-butyllithium.

Further, the solvent is at least one of tetrahydrofuran, benzene, n-hexane and cyclohexane.

Further, the molar ratio of the organolithium initiator to the olefin monomer is 1:(10-2000), preferably 1:(10-800).

Further, the molar ratio of the ethylene oxide to the organolithium initiator is (1-1.5):1.

Further, the epoxide monomer is (1) ethylene oxide, (2) ethylene oxide substituted by a linear alkyl group with 1 to 20 alkyl carbon atoms, (3) alkyl carbon atom Linear alkyl glycidyl ether with a number of 1 to 16, (4) isopropyl glycidyl ether, (5) tert-butyl glycidyl ether, (6) 2-ethylhexyl glycidyl ether, (7) benzene (8) benzyl glycidyl ether, (9) allyl glycidyl ether, (10) propargyl glycidyl ether, (11) glycidyl methacrylate and (12) butyric acid glycidyl ether at least one of glycerides. The specific structural formula is as follows:

Furthermore, the epoxide monomer is at least one of ethylene oxide, propylene oxide and butylene oxide.

Further, the organic base is a tertiary amine, amidine, guanidine, triaminophosphine or phosphazene base; the tertiary amine is triethylenediamine (DABCO), pentamethyldiethylenetriamine (PMDETA), three -at least one of (2-dimethylaminoethyl)amine (ME ₆ TREN ) and sparteine; the amidine is 1,5-diazabicyclo[4.3.0]nonane- At least one of 5-ene (DBN) and 1,8-diazabicycloundec-7-ene (DBU); the guanidine is 7-methyl-1,5,7-triaza Bicyclo[4.4.0]dec-5-ene (MTBD), 1,1,3,3-tetramethylguanidine (TMG) and 1,1,2,3,3-pentamethylguanidine (PMG) at least one of; the triaminophosphine is tris(dimethylamino)phosphine (HMTP), tris(diethylamino)phosphine (HETP), 2,8,9-trimethyl-2,5,8, 9-tetraaza-1-phosphobicyclo(3,3,3)undecane (TMAP) and 2,8,9-triisopropyl-2,5,8,9-tetraaza-1-phosphorus At least one of heterobicyclo[3.3.3]undecane (TIPAP); the phosphazene base is 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro- 1,3,2-diazaphosphorus (BEMP), tert-butylimino-tris(dimethylamino)phosphorane ( ^tBuP ₁ ), tert-butylimino-tris(pyrrolidine)phosphine ( ^tBuP ₁ (pyrr)), 1-tert-butyl-2,2,4,4,4-penta(dimethylamino)-2λ ⁵ ,4λ ⁵ -chain bis(phosphazene) ( ^t BuP ₂ ), 1-ethyl -2,2,4,4,4-penta(dimethylamino)-2λ ⁵ ,4λ ⁵ -chain bis(phosphazene) (EtP ₂ ) and 1-tert-butyl-4,4,4-tri(di At least one of methylamino)-2,2-bis[tris(dimethylamino)-phosphinylideneamino]-2λ ⁵ ,4λ ⁵ -chain bis(phosphazene) ( ^t BuP ₄ ). The specific structural formula is as follows:

Further, the organic base is 1,8-diazabicycloundec-7-ene (DBU), 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene (MTBD), 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorus (BEMP), tert-butyl imino-tris(dimethylamino)phosphorane ( ^t BuP ₁ ), 1-tert-butyl-2,2,4,4,4-penta(dimethylamino)-2λ ⁵ ,4λ ⁵ -chain di( Phosphazene) ( ^tBuP ₂ ) and 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphinylideneamino]-2λ ⁵ , at least one of 4λ ⁵ -chain bis(phosphazenes) ( ^t BuP ₄ ).

Further, the alkylborane is B-isopinepinyl-9-boronbicyclo[3.3.1]nonane (S-Alphine-Borane), tri-sec-butylborane (T ^s BuB), triiso At least one of propylborane (T ⁱ PrB), trimethylborane (TMB) and trilinear alkylborane, wherein the number of carbon atoms of the linear alkyl group in the trilinear alkylborane is 2~8. The specific structural formula is as follows:

Furthermore, the alkylboron is at least one of triethylboron and triisopropylboron.

Further, the amount of the organic/metal-free Lewis acid-base pair can be adjusted according to the designed molecular weight and the required reaction time.

Further, the molar ratio of the polyolefin macroinitiator, epoxide, organic base and alkyl boron is 1: (10-3000): (0.05-10): (0.05-10), preferably 1: (10-1000): (0.1-3): (0.1-3).

Further, before the anionic polymerization reaction, the concentration of the olefin monomer is 1-8 mol/L; before the ring-opening polymerization reaction, the concentration of the epoxy monomer is 1-10 mol/L.

Further, the polymerization reaction temperature is -80-60° C., the time is 1-48 hours, and the time for the ethylene oxide capping reaction is 1-60 minutes.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) In the present invention, the organic/metal-free catalytic system composed of organic base and alkyl boron is used for the ring-opening polymerization of epoxy monomer initiated by alkoxy lithium, so that the anionic double bond addition of olefin monomer initiated by organolithium The polymerization and the anionic ring-opening polymerization of epoxides initiated by polyolefin macromolecular alkoxide lithium can be carried out continuously and controllably in the same reactor, thereby synthesizing polyolefin-polyether block copolymers in one pot.

(2) The polymerization method provided by the invention can completely convert monomers into polymers within a few hours at room temperature, the polymerization conditions are mild, and the polymerization reaction time is shortened. At the same time, it solves the problems of insufficient polymerization activity and controllability, limited scope of application of monomers, and inflexible adjustment of catalytic activity in the existing catalytic initiation system. The polymer structure does not change when the reaction time is extended after the monomer is completely consumed.

(3) The organolithium initiator system in the present invention has versatility for olefin monomers, and is suitable for the polymerization of various olefin monomers, so it can prepare a polyolefin macroinitiator with a rich chain end of alkoxylithium. At the same time, the macromolecular initiator can fully initiate the controllable ring-opening polymerization of ethylene oxide and its derivatives in situ to obtain a complete block copolymer, and its initiation efficiency is not affected by the combination of monomers.

(4) The organic/metal-free catalytic system composed of organic bases and alkyl borons in the present invention has universal applicability to the ring-opening polymerization of epoxides initiated by lithium alkoxides, and has a high degree of chemical selectivity for the functional groups participating in the reaction properties, completely avoiding the occurrence of destructive chain transfer reactions, so that the pendant functional groups introduced by epoxy monomers can be kept intact, so that a variety of polyolefin-polyether block copolymers with clear structures can be prepared.

(5) The present invention can make the composition ratio of the monomer unit and the molecular weight of the copolymer (in 1.0～100.0 kg/mol range) is precisely controllable, and the molecular weight dispersion of the copolymer Generally below 1.2. In addition, the mass ratio of polyolefin and polyether can be controlled as (10-90%): (90-10%), and the glass transition temperature and mechanical properties of different copolymers are quite different, thus enriching the polyolefin-poly Structure and properties of ether block copolymers.

(6) The raw materials of the amphiphilic block copolymer provided by the present invention are easy to obtain, the synthesis method is simple, and it is suitable for industrial production.

Description of drawings

Fig. 1 is the SEC curve of polyisoprene macroinitiator (PI) and polyisoprene-b-polyethylene oxide (PI-b-PEO) prepared in Example 6 of the present invention.

Fig. 2 is the ¹ H NMR spectrum of polyisoprene-b-polyethylene oxide (PI-b-PEO) prepared in Example 6 of the present invention.

Fig. 3 is the polystyrene-b-polyisoprene macroinitiator (PS-b-PI), polystyrene-b-polyisoprene-b-polyepoxide prepared in Example 14 of the present invention Ethane (PS-b-PI-b-PEO) and polystyrene-b-polyisoprene-b-polyethylene oxide-b-polypropylene oxide (PS-b-PI-b-PEO -b-SEC curve of PPO).

Fig. 4 is the polystyrene-b-polyisoprene-b-polyethylene oxide-b-polypropylene oxide (PS-b-PI-b-PEO-b-PPO prepared by Example 14 of the present invention ) ¹ H NMR spectrum.

Detailed ways

The present invention will be further described in detail below with reference to the examples and drawings, but the implementation of the present invention is not limited thereto.

In the embodiment of the present invention, if no specific conditions are indicated, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The raw materials, reagents, etc. of manufacturers not indicated are all conventional products that can be purchased from the market.

The conversion rate of the monomer and the structural characteristics of the copolymer were measured by a Bruker AV400 liquid nuclear magnetic resonance instrument, and the solvent was deuterated chloroform.

The molecular weight and molecular weight dispersion of the polymer were measured by size exclusion chromatography (SEC). The instrument was an Agilent (Agilent) 1260 Infinity size exclusion chromatography. The mobile phase was tetrahydrofuran, the column temperature was 35°C, and the flow rate was 1mL/min; A series of polystyrene standard samples were used to make a calibration curve.

The parts described in the formula in the following examples are all molar parts.

Example 1

Anionic polymerization of isoprene was carried out in tetrahydrofuran with n-butyllithium as the initiator and capped with ethylene oxide. Subsequently, the ring-opening polymerization of ethylene oxide was carried out by using the active polyisoprene capped with ethylene oxide as the macroinitiator and the organic/metal-free Lewis acid-base pair as the catalyst, and the polyisoprene was prepared in one pot. - Polyethylene oxide amphiphilic block copolymers. The specific operation is as follows:

Isoprene, ethylene oxide and tetrahydrofuran are used after water removal treatment. In an inert atmosphere, 1 part of n-butyllithium, 150 parts of isoprene and tetrahydrofuran (the initial concentration of isoprene is 1.5 mol/L) were added into the reactor pre-cooled to -78 °C and stirred for 12 h. Subsequently, 300 parts of ethylene oxide was added into the reactor, and stirring was continued for 30 min at -78°C. Then add 1 part of phosphazene base ^tBuP ₁ and 3 parts of tetrahydrofuran solution of triethylboron, the concentration of ethylene oxide before the ring-opening polymerization reaction is 2.6mol/L, and stir at room temperature for 12 hours. The reaction was terminated with acetic acid, the crude product was collected, precipitated with ether, dried in vacuo, and obtained. The molecular weight of the crude product measured by SEC was 25.2 kg/mol, and the degree of dispersion was 1.08. The conversion rates of isoprene and ethylene oxide were both 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (PI-b-PEO) calculated from the feed ratio of n-butyllithium, isoprene and ethylene oxide and the conversion rate is 23.5 kg/mol. The molar ratio of n-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:1:3.

Example 2

Anionic polymerization of isoprene was carried out in tetrahydrofuran with n-butyllithium as the initiator and capped with ethylene oxide. Subsequently, the ring-opening polymerization of ethylene oxide was carried out by using the active polyisoprene capped with ethylene oxide as the macroinitiator and the organic/metal-free Lewis acid-base pair as the catalyst, and the polyisoprene was prepared in one pot. - Polyethylene oxide amphiphilic block copolymers. The specific operation is as follows:

Isoprene, ethylene oxide and tetrahydrofuran were all dried before use. In an inert atmosphere, add 1 part of n-butyllithium, 1000 parts of isoprene and an appropriate amount of tetrahydrofuran (the initial concentration of isoprene is 3.0 mol/L) into the reactor pre-cooled to -78 °C and stir for 24 h . Then add 2000 parts of ethylene oxide into the reactor, and continue stirring at -78°C for 10 minutes. Then add 1 part of phosphazene base ^tBuP ₂ and 3 parts of tetrahydrofuran solution of triethylboron, the concentration of ethylene oxide before the ring-opening polymerization reaction is 4.6mol/L, and stir at room temperature for 24 hours. The reaction was terminated with acetic acid, the crude product was collected, precipitated with ether, dried in vacuo, and obtained. The molecular weight of the crude product measured by SEC was 126.6 kg/mol, and the degree of dispersion was 1.15. The conversion rates of isoprene and ethylene oxide were both 100% as measured by ¹ H NMR. The theoretical number-average molecular weight M _n,th (PI-b-PEO) calculated from the feed ratio of n-butyllithium, isoprene and ethylene oxide and the conversion rate was 156.2 kg/mol. The molar ratio of n-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:1:3.

Example 3

Anionic polymerization of isoprene was carried out in tetrahydrofuran with n-butyllithium as the initiator and capped with ethylene oxide. Subsequently, the active polyisoprene terminated with ethylene oxide was used as a macroinitiator, and the organic/metal-free Lewis acid-base pair was used as a catalyst to carry out the ring-opening polymerization of propylene oxide to prepare polyisoprene- Polypropylene oxide block copolymer. The specific operation is as follows:

Isoprene, ethylene oxide, propylene oxide and tetrahydrofuran are used after water removal treatment. In an inert atmosphere, add 1 part of n-butyllithium, 150 parts of isoprene and an appropriate amount of tetrahydrofuran (the initial concentration of isoprene is 5.0 mol/L) into the reactor pre-cooled to -78 °C and stir for 12 h . Then add 1 part of ethylene oxide into the reactor, and continue stirring at -78°C for 20 min. Then add 300 parts of propylene oxide, 1 part of phosphazene base ^tBuP ₄ and 3 parts of tetrahydrofuran solution of triethylboron. The concentration of propylene oxide before the ring-opening polymerization reaction is 5.9 mol/L, and stir at room temperature for 24 hours. The reaction was terminated with acetic acid, and the crude product was collected and dried in vacuo to obtain the obtained product. The molecular weight of the crude product measured by SEC was 30.1 kg/mol, and the degree of dispersion was 1.13. The conversion rates of isoprene and propylene oxide were both 100% as measured by ¹ H NMR. The theoretical number-average molecular weight M _n,th (PI-b-PPO) calculated from the feed ratio of n-butyllithium, isoprene and propylene oxide and the conversion rate is 27.7 kg/mol. The molar ratio of n-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:1:3.

Example 4

Anionic polymerization of isoprene was carried out in tetrahydrofuran with n-butyllithium as the initiator and capped with ethylene oxide. Subsequently, using ethylene oxide-terminated polyisoprene as a macroinitiator and an organic/metal-free Lewis acid-base pair as a catalyst, the ring-opening polymerization of butylene oxide was carried out to prepare polyisoprene- Polybutylene oxide block copolymer. The specific operation is as follows:

Isoprene, ethylene oxide, butylene oxide and tetrahydrofuran are used after water removal treatment. In a nitrogen atmosphere, add 1 part of n-butyllithium, 100 parts of isoprene and an appropriate amount of tetrahydrofuran (the initial concentration of isoprene is 5.0 mol/L) into the reactor pre-cooled to -78 °C and stir for 12 h . Then add 1 part of ethylene oxide into the reactor, and continue to stir at -78°C for 10 min. Then add 300 parts of butylene oxide, 1 part of phosphazene base ^tBuP ₂ and 2 parts of tetrahydrofuran solution of triethylboron. The concentration of butylene oxide before the ring-opening polymerization reaction is 6.5 mol/L, and stir at room temperature for 24 hours. The reaction was terminated with acetic acid, and the crude product was collected and dried in vacuo to obtain the obtained product. The molecular weight of the crude product measured by SEC was 26.4 kg/mol, and the degree of dispersion was 1.12. The conversion rates of isoprene and butylene oxide were both 100% as measured by ¹ H NMR. The theoretical number-average molecular weight M _n,th (PI-b-PBO) calculated by the feed ratio of n-butyllithium, isoprene and butylene oxide and the conversion rate is 28.5 kg/mol. The molar ratio of n-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:1:2.

Example 5

Anionic copolymerization of isoprene and butadiene was carried out in tetrahydrofuran with n-butyllithium as the initiator and capped with ethylene oxide. Subsequently, the ring-opening polymerization of ethylene oxide was carried out by using ethylene oxide-terminated polyolefin as a macroinitiator and an organic/metal-free Lewis acid-base pair as a catalyst to prepare poly(isoprene-co- Butadiene)-polyethylene oxide amphiphilic block copolymer. The specific operation is as follows:

Isoprene, butadiene, ethylene oxide and tetrahydrofuran are used after water removal treatment. In an inert atmosphere, add 1 part of n-butyllithium, 200 parts of isoprene, 200 parts of butadiene and an appropriate amount of tetrahydrofuran (both initial concentrations of isoprene and butadiene are 2.0 mol/L) to the pre- Cooled to -78°C reactor and stirred for 12h. Then add 400 parts of ethylene oxide into the reactor, and continue to stir for 40 minutes at -78°C. Then add 1 part of phosphazene base ^tBuP ₄ and 5 parts of tetrahydrofuran solution of triisopropylboron, the concentration of ethylene oxide before the ring-opening polymerization reaction is 3.3mol/L, and stir at 50°C for 6h. The reaction was terminated with acetic acid, the crude product was collected, precipitated with methanol, and dried in vacuo to obtain the obtained product. The molecular weight of the crude product measured by SEC was 38.6 kg/mol, and the degree of dispersion was 1.18. The conversion rates of isoprene, butadiene and ethylene oxide were all 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (P(I-co-B)-b-PEO) calculated by the feed ratio and conversion rate of n-butyllithium, isoprene, butadiene and ethylene oxide is 42.1 kg/mol. The molar ratio of n-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:1:5.

Example 6

Anionic polymerization of isoprene was carried out in benzene with sec-butyllithium as the initiator and capped with ethylene oxide. Subsequently, using ethylene oxide-terminated polyisoprene as a macroinitiator and an organic/metal-free Lewis acid-base pair as a catalyst, the ring-opening polymerization of ethylene oxide was carried out to prepare polyisoprene- Polyethylene oxide amphiphilic block copolymer. The specific operation is as follows:

Isoprene, ethylene oxide and benzene are used after water removal treatment. In an inert atmosphere, add 1 part of sec-butyllithium, 150 parts of isoprene and an appropriate amount of benzene (the initial concentration of isoprene is 2.0 mol/L) into a dry reactor, and stir at room temperature for 12 hours. Then add 300 parts of ethylene oxide into the reactor, and continue stirring at room temperature for 30 minutes. Then add 1 part of cyclic amidine DBU and 10 parts of tetrahydrofuran solution of triethylboron, the concentration of ethylene oxide before ring-opening polymerization is 3.3 mol/L, and stir at room temperature for 12 hours. The reaction was terminated with acetic acid, the crude product was collected, precipitated with ether, dried in vacuo, and obtained. The molecular weight of the crude product measured by SEC was 24.6 kg/mol, and the degree of dispersion was 1.06. The conversion rates of isoprene and ethylene oxide were both 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (PI-b-PEO) calculated from the feed ratio of sec-butyllithium, isoprene and ethylene oxide and the conversion rate is 23.5 kg/mol. The molar ratio of sec-butyllithium, organic base and alkyl boron in the catalytic initiation system described in this example is 1:1:10.

Example 7

The solvent was changed to a mixture of tetrahydrofuran and benzene, the volume ratio of tetrahydrofuran and benzene was 1:4, the initial concentration of isoprene and ethylene oxide was unchanged, and the others were the same as in Example 6 to obtain polyisoprene- Polyethylene oxide block copolymer. The molecular weight of the crude product measured by SEC was 21.1 kg/mol, and the degree of dispersion was 1.15. The conversion rates of isoprene and ethylene oxide were both 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (PI-b-PEO) calculated from the feed ratio of sec-butyllithium, isoprene and ethylene oxide and the conversion rate is 23.5 kg/mol.

Example 8

Anionic polymerization of styrene was carried out in benzene with sec-butyllithium as the initiator and capped with ethylene oxide. Then, using ethylene oxide-terminated polystyrene as a macroinitiator and an organic/metal-free Lewis acid-base pair as a catalyst, the ring-opening polymerization of ethylene oxide was carried out to prepare polystyrene-polyethylene oxide in one pot. Alkane amphiphilic block copolymers. The specific operation is as follows:

Styrene, ethylene oxide and benzene are used after water removal treatment. In an inert atmosphere, add 1 part of sec-butyllithium, 200 parts of styrene and an appropriate amount of benzene (the initial concentration of styrene is 5.0 mol/L) into a dry reactor, and stir at room temperature for 12 hours. Then add 500 parts of ethylene oxide into the reactor, and continue to stir at room temperature for 10 min. Then add 0.75 parts of phosphazene base ^tBuP ₄ and 3 parts of triethylboron tetrahydrofuran solution, the concentration of ethylene oxide before the ring-opening polymerization reaction is 7.7mol/L, and stir at room temperature for 24 hours. The reaction was terminated with acetic acid, the crude product was collected, precipitated with ether, dried in vacuo, and obtained. The molecular weight of the crude product measured by SEC was 46.6 kg/mol, and the degree of dispersion was 1.10. The conversions of styrene and ethylene oxide were both 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (PS-b-PEO) calculated by the feed ratio of sec-butyllithium, styrene and ethylene oxide and the conversion rate is 42.9 kg/mol. The molar ratio of sec-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:0.75:3.

Example 9

Change the consumption of styrene and oxirane into 1000 and 2000 parts respectively (the initial concentration of styrene and oxirane is respectively 5.0mol/L and 6.7mol/L), other is identical with embodiment 8, obtains Styrene-polyethylene oxide amphiphilic block copolymer. The molecular weight of the crude product measured by SEC was 153.4 kg/mol, and the degree of dispersion was 1.19. The conversions of styrene and ethylene oxide were both 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (PS-b-PEO) calculated by the feed ratio of sec-butyllithium, styrene and ethylene oxide and the conversion rate is 192.1kg/mol.

Example 10

Anionic copolymerization of isoprene and butadiene was carried out in benzene with sec-butyllithium as the initiator and capped with ethylene oxide. Subsequently, the ring-opening polymerization of ethylene oxide was carried out by using ethylene oxide-terminated poly(isoprene-co-butadiene) as a macroinitiator and an organic/metal-free Lewis acid-base pair as a catalyst. Preparation of poly(isoprene-co-butadiene)-polyethylene oxide amphiphilic block copolymers. The specific operation is as follows:

Isoprene, butadiene, ethylene oxide and benzene are used after water removal treatment. In an inert atmosphere, mix 1 part of sec-butyllithium, 200 parts of isoprene, 300 parts of butadiene and an appropriate amount of benzene (the initial concentrations of isoprene and butadiene are 2.0 mol/L and 3.0 mol/L, respectively. L) was added into a dry reactor and stirred at room temperature for 12h. Then add 1000 parts of ethylene oxide into the reactor, and continue stirring at room temperature for 20 minutes. Then add 1 part of phosphazene base BEMP and 10 parts of triethylboron tetrahydrofuran solution, the concentration of ethylene oxide before the ring-opening polymerization reaction is 6.7mol/L, and stir at room temperature for 24 hours. The reaction was terminated with acetic acid, the crude product was collected, precipitated with ether, dried in vacuo, and obtained. The molecular weight of the crude product measured by SEC was 68.5 kg/mol, and the degree of dispersion was 1.15. The conversion rates of isoprene, butadiene and ethylene oxide were all 100% as measured by ¹ H NMR. The theoretical number average molecular weight _Mn,th (P(I-co-B)-b-PEO) calculated by the feed ratio and conversion rate of sec-butyllithium, isoprene, butadiene and ethylene oxide is: 73.9 kg/mol. The molar ratio of sec-butyllithium, organic base and alkyl boron in the catalytic initiation system described in this example is 1:1:10.

Example 11

Change the copolymerized olefin monomer into isoprene and styrene, and the consumption of isoprene and styrene is 200 parts and 100 parts respectively (the initial concentrations of isoprene, butadiene and ethylene oxide are respectively 2.0mol/L, 1.0mol/L and 6.7mol/L), others are identical with embodiment 10, get poly(isoprene-co-styrene)-polyethylene oxide amphiphilic block copolymer . The molecular weight of the crude product measured by SEC was 66.3 kg/mol, and the degree of dispersion was 1.10. The conversion rates of isoprene, styrene and ethylene oxide were all 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (P(I-co-S)-b-PEO) calculated by the feed ratio and conversion rate of sec-butyllithium, isoprene, styrene and ethylene oxide is 68.1 kg/mol.

Example 12

The olefin monomer of copolymerization is changed into butadiene and styrene, and the consumption of butadiene, styrene and oxirane is respectively 400 parts, 50 parts and 500 parts (butadiene, styrene and oxirane The initial concentration is respectively 2.0mol/L, 0.25mol/L and 4.0mol/L), others are identical with embodiment 10, obtain poly(butadiene-co-styrene)-polyethylene oxide amphiphilic intercalation segment copolymers. The molecular weight of the crude product measured by SEC was 58.8 kg/mol, and the degree of dispersion was 1.21. The conversion rates of butadiene, styrene and ethylene oxide were all 100% as measured by ¹ H NMR. The theoretical number average molecular weight M _n,th (P(B-co-S)-b-PEO) calculated by the feed ratio and conversion rate of sec-butyllithium, butadiene, styrene and ethylene oxide is 48.9kg /mol.

Example 13

Anionic block copolymerization of butadiene and isoprene was carried out in benzene with sec-butyllithium as the initiator and capped with ethylene oxide. Subsequent ring-opening polymerization of butylene oxide was carried out using ethylene oxide-terminated polybutadiene-b-polyisoprene as a macroinitiator and an organic/metal-free Lewis acid-base pair as a catalyst in a one-pot process Preparation of polybutadiene-polyisoprene-polybutylene oxide triblock copolymer. The specific operation is as follows:

Butadiene, isoprene, ethylene oxide, butylene oxide and benzene are used after water removal treatment. In an inert atmosphere, add 1 part of sec-butyllithium, 100 parts of butadiene and an appropriate amount of benzene (the initial concentration of butadiene is 2.0 mol/L) into a dry reactor, and stir at room temperature for 12 hours. Then add 200 parts of isoprene into the reactor, and stir at room temperature for 12 hours. Subsequently, 1 part of ethylene oxide was added into the reactor, and stirring was continued for 30 min at room temperature. Then add 300 parts of butylene oxide, 5 parts of guanidine MTBD and 10 parts of triisopropylborane tetrahydrofuran solution, the concentration of butylene oxide before the ring-opening polymerization reaction is 3.1 mol/L, and stir at room temperature for 6 hours. The reaction was terminated with acetic acid, the crude product was collected, precipitated with methanol, and dried in vacuo to obtain the obtained product. The molecular weight of the crude product measured by SEC was 39.8 kg/mol, and the degree of dispersion was 1.18. The conversion rates of butadiene, isoprene and butylene oxide were all 100% as measured by ¹ H NMR. The theoretical number-average molecular weight M _n,th (PI-b-PB-b-PBO) calculated by the charging ratio and conversion ratio of sec-butyllithium, butadiene, isoprene and butylene oxide is 40.7kg/ mol. The molar ratio of sec-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:5:10.

Example 14

Anionic block copolymerization of styrene and isoprene in benzene with sec-butyllithium as initiator and capping with ethylene oxide; subsequent ethylene oxide capped polystyrene-b- Polyisoprene is used as a macromolecular initiator, organic/metal-free Lewis acid-base pair is used as a catalyst, and the ring-opening polymerization of ethylene oxide and propylene oxide is carried out in sequence to prepare polystyrene-polyisoprene in one pot -Polyethylene oxide-polypropylene oxide tetrablock copolymer. The specific operation is as follows:

Styrene, isoprene, ethylene oxide, propylene oxide and benzene are used after water removal treatment. In an inert atmosphere, add 1 part of sec-butyllithium, 100 parts of styrene and an appropriate amount of benzene (the initial concentration of styrene is 4.0 mol/L) into a dry reactor, and stir at room temperature for 12 h. Then 200 parts of isoprene was added into the reactor and stirred at room temperature for 12 hours. Then add 100 parts of ethylene oxide, continue stirring at room temperature for 20 minutes, then add 2 parts of phosphazene base ^tBuP ₂ and 5 parts of triethylboron in tetrahydrofuran solution, the concentration of ethylene oxide before ring-opening polymerization is 2.0mol/L , stirred at room temperature for 3h. Then add 100 parts of propylene oxide and stir at room temperature for 6h. The reaction was terminated with acetic acid, the crude product was collected, precipitated with methanol, and dried in vacuo to obtain the obtained product. The molecular weight of the crude product measured by SEC was 43.6 kg/mol, and the degree of dispersion was 1.20. The conversion rates of styrene, isoprene, ethylene oxide and propylene oxide were all 100% as measured by ¹ H NMR. Theoretical number-average molecular weight M _n,th (PS-b-PI-b-PEO-b -PPO) was 34.3 kg/mol. The molar ratio of sec-butyllithium, organic base and alkylboron in the catalytic initiation system described in this example is 1:2:5.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (9)

1. A process for the block copolymerization of olefins and epoxides comprising the steps of:

in inert or nitrogen atmosphere, taking olefin as a monomer, taking organolithium as an initiator, carrying out anionic polymerization reaction of the olefin in a solvent, and then adding ethylene oxide to end-cap the polyolefin to obtain active polyolefin with chain end of lithium alkoxide; taking active polyolefin with chain end of lithium alkoxide as a macromolecular initiator, adding an epoxide monomer, an organic base and an organic/non-metal Lewis acid base composed of alkyl boron into the active polyolefin to perform ring-opening polymerization reaction on the catalyst, and preparing the polyolefin-polyether segmented copolymer with controllable structure by one-pot method;

the molar ratio of the organolithium initiator to the olefin monomer is 1: (10-2000); the molar ratio of the polyolefin macroinitiator to the epoxide to the organic base to the alkyl boron is 1: (10-3000): (0.05-10): (0.05-10); the molar ratio of the ethylene oxide to the organolithium initiator is (1-1.5): 1.

2. the method for block copolymerization of an olefin and an epoxide according to claim 1, wherein the molar ratio of the organolithium initiator to the olefin monomer is 1: (10-800); the molar ratio of the polyolefin macroinitiator to the epoxide to the organic base to the alkyl boron is 1: (10-1000): (0.1-3): (0.1-3).

3. The method for block copolymerization of olefin and epoxide according to claim 1, wherein the polymerization temperatures are-80-60 ℃ and the polymerization times are 1-48 h; the time of the ethylene oxide end capping reaction is 1 to 60 minutes.

4. The method for block copolymerization of olefin and epoxide according to claim 1, wherein the organolithium initiator is R-Li, R is one of alkyl, cycloalkyl or aryl having 1 to 14 carbon atoms, and Li is a lithium atom;

the organic base is tertiary amine, amidine, guanidine, triaminophosphine or phosphazene base; the tertiary amine is at least one of triethylene diamine, pentamethylene diethylenetriamine, tri- (2-dimethylaminoethyl) amine and cytisine; the amidine is 1, 5-diazabicyclo [4.3.0]At least one of non-5-ene and 1, 8-diazabicycloundec-7-ene; the guanidine is 7-methyl-1, 5, 7-triazabicyclo [4.4.0]At least one of dec-5-ene, 1, 3-tetramethylguanidine, and 1,2, 3-pentamethylguanidine; by a means ofThe triaminophosphines are tris (dimethylamino) phosphine, tris (diethylamino) phosphine, 2,8, 9-trimethyl-2,5,8,9-tetraaza-1-phosphabicyclo (3, 3) undecane and 2,8, 9-triisopropyl-2,5,8,9-tetraaza-1-phosphabicyclo [3.3.3 ]]At least one of undecane; the phosphazene base is 2-tertiary butyl imino-2-diethyl amino-1, 3-dimethyl perhydro-1, 3, 2-diazaphosphorus, tertiary butyl imino-tris (dimethylamino) phosphorane, tertiary butyl imino-tris (pyrrolidine) phosphine, 1-tertiary butyl-2, 4-penta (dimethylamino) -2lambda ⁵ ,4λ ⁵ -chain di (phosphazene), 1-ethyl-2, 4-penta (dimethylamino) -2λ ⁵ ,4λ ⁵ -chain di (phosphazene) and 1-tert-butyl-4, 4-tris (dimethylamino) -2, 2-bis [ tris (dimethylamino) -phosphinideneamino]-2λ ⁵ ,4λ ⁵ -at least one of chain di (phosphazene);

the alkyl boron is at least one of B-isoppinyl-9-boron bicyclo [3.3.1] nonane, tri-sec-butyl borane, triisopropyl borane, trimethyl borane and tri-linear alkyl borane, wherein the carbon number of the linear alkyl in the tri-linear alkyl borane is 2-8.

5. The process for the block copolymerization of olefins and epoxides according to claim 4, wherein the organolithium initiator is n-butyllithium and/or sec-butyllithium; the organic base is 1, 8-diazabicyclo undec-7-ene, 7-methyl-1, 5, 7-triazabicyclo [4.4.0]Dec-5-ene, 2-tert-butylimino-2-diethylamino-1, 3-dimethylperfhydro-1, 3, 2-diazaphosphorus, tert-butylimino-tris (dimethylamino) phosphorane, 1-tert-butyl-2, 4-penta (dimethylamino) -2λ ⁵ ,4λ ⁵ -chain di (phosphazene) and 1-tert-butyl-4, 4-tris (dimethylamino) -2, 2-bis [ tris (dimethylamino) -phosphinideneamino]-2λ ⁵ ,4λ ⁵ -at least one of chain di (phosphazene); the alkyl boron is at least one of triethylboron and triisopropylboron.

6. The method for block copolymerization of an olefin and an epoxide according to claim 1, wherein the olefin monomer is at least one of butadiene, isoprene, styrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2, 4-dimethylstyrene and 2, 5-dimethylstyrene;

the epoxide monomer is at least one of ethylene oxide, linear alkyl substituted ethylene oxide with 1-20 alkyl carbon atoms, linear alkyl glycidyl ether with 1-16 alkyl carbon atoms, 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 and glycidyl butyrate.

7. The method for block copolymerization of an olefin and an epoxide according to claim 6, wherein the olefin monomer is at least one of isoprene, butadiene and styrene; the epoxide monomer is at least one of ethylene oxide, propylene oxide and butylene oxide.

8. The method for block copolymerization of an olefin and an epoxide according to claim 1, wherein the concentration of the olefin monomer is 1 to 8mol/L before the anionic polymerization; the concentration of epoxide monomer is 1-10 mol/L before ring-opening polymerization.

9. The method for block copolymerization of an olefin and an epoxide according to claim 1, wherein the solvent is at least one of tetrahydrofuran, benzene, n-hexane and cyclohexane.