CN107056976A - A kind of reverse atom transfer radical polymerization method of alkali activation halogenated hydrocarbons effect - Google Patents

Abstract

The present invention provides a kind of reverse atom transfer radical polymerization method of alkali activation halogenated hydrocarbons effect, the polymerization is without using organic ligand and radical initiator, polymerization system includes vinyl monomer, halogenated hydrocarbons, alkali and high-valence state transition-metal catalyst, monomer is carried out polymer of the reverse atom transfer radical polymerization reaction generation with Narrow Molecular Weight Distribution to the activation of halogenated hydrocarbons by alkali.The polymerization avoids the use of radical initiator and the sensitive lower valency transition-metal catalyst of water oxygen, while overcoming expensive, environmental pollution the defect that existing atom transfer radical polymerization method is existed using poisonous, volatile organic compound as part.

Description

A Reverse Atom Transfer Radical Polymerization Method Based on Alkali Activation of Halogenated Hydrocarbons

technical field

The invention belongs to the field of macromolecule synthesis, and in particular relates to a reverse atom transfer radical polymerization method in which alkali activates halogenated hydrocarbons, and is a new controllable radical polymerization method.

Background technique

Atom transfer radical polymerization (ATRP) has become the most important "living"/controllable radical polymerization method because of its advantages such as a wide variety of applicable monomers, strong molecular design, and narrow product molecular weight distribution. The traditional atom transfer radical polymerization method uses low-valence transition metal catalysts to interact with organic ligands (such as compounds containing P and N, organic acids, ionic liquids, etc.) to endow the system with higher activity. However, low-valence transition metals are easily oxidized and sensitive to moisture and air; organic ligand components are expensive and highly toxic; catalyst/ligand systems are used in large amounts, and the post-treatment steps of polymerization products are cumbersome and costly. Application and industrialization of the method.

In order to overcome the shortcomings of using low-valence catalysts and organic compound ligands in the traditional atom transfer radical polymerization method, a reverse atom transfer radical polymerization method using free radical initiators in combination with high-valence metal catalysts was proposed. The polymerization reaction needs to be carried out in a polar solvent containing an amide group (such as dimethylformamide, vinylpyrrolidone, dimethylimidazolinone, etc.), which shows better controllable reaction characteristics. However, the polar solvent used in this method volatilizes seriously, which is very harmful to human health and the environment. At the same time, the reverse atom transfer radical polymerization method requires the use of traditional radical initiators, which have poor stability and tend to form homopolymers in the process of preparing block copolymers. These defects also restrict the green development direction of the reverse atom radical polymerization method.

Contents of the invention

In view of the above defects or improvement needs of the prior art, the object of the present invention is to provide a new method of reverse atom transfer radical polymerization in which alkali activates the action of halogenated hydrocarbons, which promotes the cleavage of carbon-halogen bonds through the activation of halogenated hydrocarbons by alkalis, Without the use of free radical initiators and low-valence state transition metal catalysts sensitive to water and oxygen, the controllable polymerization of reverse atom transfer radicals of polymerized monomers is realized, and at the same time, it overcomes the toxic and easy to use of existing atom transfer radical polymerization methods. Volatile organic compounds (such as compounds containing P and N, organic acids, ionic liquids, and raw materials containing amide groups, etc.) are expensive and pollute the environment as ligands.

According to one aspect of the present invention, there is provided a method of reverse atom transfer radical polymerization in which alkali activates halogenated hydrocarbons. The polymerization method does not use organic ligands and free radical initiators. The polymerization system includes vinyl monomers, halogenated Hydrocarbons, alkalis and high-valence state transition metal catalysts, through the activation of halogenated hydrocarbons by alkalis, the vinyl monomers undergo reverse atom transfer radical polymerization to generate polymers with narrow molecular weight distribution.

Preferably, the reverse atom transfer radical polymerization method of alkali-activated halogenated hydrocarbons specifically comprises the following steps:

(1) Under the condition of anhydrous and oxygen isolation, uniformly mix the vinyl monomer, alkali, high-valence transition metal catalyst and halogenated hydrocarbon to form a pre-reaction mixture;

Wherein, the molar ratio of the vinyl monomer to the high-valent state transition metal catalyst is 200:1-500:1; the molar ratio of the vinyl monomer to the halogenated hydrocarbon is 200:1-500:1; The molar ratio of the base to the high-valence transition metal catalyst is 0.2:1 to 4:1;

(2) Putting the pre-reaction mixture in step (1) at a predetermined reaction temperature to react, and the vinyl monomer starts to undergo reverse atom transfer radical polymerization to generate a polymer with a narrow molecular weight distribution.

Preferably, the reactive radical initiator is an azo initiator or a peroxide initiator.

Preferably, the vinyl monomer is at least one of methyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate, styrene, vinyl chloride, acrylic acid, acrylamide, acrylonitrile and vinyl acetate A sort of;

The halogenated hydrocarbon is ethyl 2-bromophenylacetate, ethyl 2-bromoisobutyrate, methyl 2-bromoisobutyrate, ethyl 2-bromopropionate, 2-bromoethylbenzene, chloroacetic acid Any one of ethyl ester, 2-chloropropionitrile and 2-bromopropionitrile;

Described base is at least one in inorganic base or organic base, and wherein said inorganic base is sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, sodium phosphate, disodium hydrogen phosphate , at least one of sodium dihydrogen phosphate, sodium thiosulfate, iron hydroxide and basic aluminum oxide; the organic base is potassium methylate, sodium tert-butoxide, potassium tert-butoxide, butyllithium, butyl At least one of base magnesium, butyl magnesium chloride, ethanolamine, ethylenediamine, triethylamine, imidazole and 1,8-diazabicycloundec-7-ene;

The high-valence transition metal catalyst is a high-valence metal halide, preferably at least one of ferric bromide, copper bromide, ferric chloride and ferric chloride hexahydrate.

Preferably, the pre-reaction mixture in step (1) is obtained by stirring and mixing for 20-30 minutes under a protective gas atmosphere.

Preferably, the protective gas is nitrogen or an inert gas.

Preferably, the predetermined reaction temperature in step (2) is 50°C to 120°C.

Preferably, the reverse atom transfer radical polymerization reaction time in step (2) is not less than 3 hours.

Preferably, the reverse atom transfer radical polymerization reaction time is 3-15 hours.

Preferably, the reverse atom transfer radical polymerization reaction of the alkali-activated halogenated hydrocarbon is terminated by cooling the reaction system, and the polymer having a narrow molecular weight distribution is obtained by removing the catalyst, alkali, etc. And unreacted vinyl monomer purification.

Preferably, the molecular weight distribution index of the narrow molecular weight distribution polymer in step (2) is 1.07-1.25.

Compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

The reverse atom transfer radical polymerization of the present invention avoids azo or peroxy free radical initiators due to the reverse atom transfer radical polymerization carried out under the action of alkali-activated halogenated hydrocarbons

(e.g., azobisisobutyronitrile, azobisisoheptanonitrile, azobismethoxyisoheptanonitrile, dibenzoyl peroxide, and diethylhexyl peroxydicarbonate) and water- and oxygen-sensitive low The use of valence state transition metal catalysts overcomes the organic compound or polar solvent (such as containing P, N compound, organic acid, ionic liquid, and the raw material containing amide group, etc.) of atom transfer radical polymerization system in the prior art simultaneously as Ligands have disadvantages such as high price, high toxicity and volatility, which can reduce the degree of damage to the environment and the cost of the reaction.

The present invention introduces cheap, easy-to-obtain, non-toxic bases (inorganic bases and organic bases) into the system, and the reaction rate and product conversion rate can be further regulated by adjusting the type and amount of bases. The introduction of the base directly activates the carbon-halogen bond of the halogenated hydrocarbon and promotes the generation of active free radicals, thereby reducing the high-valence transition metals and enabling the reverse atom transfer radical polymerization to proceed.

The present invention can avoid the use of azo-type, peroxy-type free radical initiators and organic compounds or polar solvents and other external ligands, and proposes a new polymerization implementation method, which solves the problem of raw materials for traditional atom transfer radical polymerization reactions The problems of high cost and high toxicity reduce the cost of raw materials for atom transfer radical polymerization and make the system more environmentally friendly. The base required in the present invention is an inorganic base and an organic base, which are simple and easy to obtain.

The reverse atom transfer radical polymerization method of the alkali-activated halogenated hydrocarbon in the present invention is applicable to the polymerization of various vinyl monomers, such as methyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate , styrene, vinyl chloride, acrylic acid, acrylamide, acrylonitrile and vinyl acetate; the base used can be an inorganic base (such as sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide , sodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, etc.), or an organic base (such as ethanolamine, ethylenediamine, triethylamine, imidazole, etc.).

In the present invention, the molar ratio of vinyl monomer and catalyst in reverse atom transfer radical polymerization is preferably controlled at 200:1 to 500:1, and the molar ratio of vinyl monomer and halogenated hydrocarbon is preferably controlled at 200:1 ～500:1, the molar ratio of base and catalyst is preferably controlled to be 0.2:1～4:1; by controlling the ratio of each reaction raw material (especially the addition ratio of base), and through the overall coordination of each reaction condition, it can ensure the reaction The efficient occurrence of atom transfer radical polymerization ensures proper reaction rate, product conversion, and polymerization control. In addition, in the present invention, the reaction temperature of the reverse electron transfer radical polymerization reaction is preferably 50° C. to 120° C., and the reaction time is preferably 3 hours or more (or 3 to 15 hours), so as to ensure the formation of a specific target polymer product.

In the present invention, the introduction of the base can directly activate the carbon-halogen bond of the halogenated hydrocarbon without adding any additional ligands, reduce the oxidation-reduction potential of the halogenated hydrocarbon, accelerate the generation of active free radicals, and make the electron transfer It is more likely to occur, thereby reducing the high-valence transition metal catalyst and allowing the reverse atom transfer radical polymerization to occur.

The present invention combines alkali and atom transfer radical polymerization methods, and on the basis of good controllability of atom transfer radical polymerization, through the introduction of alkali, a reverse atom transfer without ligand and free radical initiator is constructed The new method of free radical polymerization speeds up the existing reaction process, reduces the cost of raw materials, and simplifies the post-treatment process, which has great guiding significance for the development of green and environmentally friendly atom transfer radical polymerization systems.

Description of drawings

Fig. 1 is the polymerization system [methyl methacrylate] ₀ :[2-bromophenyl acetate ethyl ester] ₀ :[iron bromide] ₀ :[sodium hydroxide] ₀ =200:1:1 in embodiment 2 2 Polymerization kinetics curves of reactions at 60°C and 90°C respectively;

Fig. 2 is the polymerization system [methyl methacrylate] ₀ : [ethyl 2-bromophenylacetate] ₀ : [iron bromide] ₀ : [sodium carbonate] ₀ =200:1:1:4 in embodiment 3 The molecular weight and molecular weight distribution curve of the reaction at 60°C;

Fig. 3 shows the halohydrocarbon system used in Example 7, and explored the action of alkali to change the oxidation-reduction potential of the halohydrocarbon by cyclic voltammetry.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

In the present invention, the reverse atom transfer radical polymerization method of alkali-activated halogenated hydrocarbons does not use organic ligands and free radical initiators, and the polymerization system includes vinyl monomers, halogenated hydrocarbons, alkalis and high-valence state transitions Metal catalyst, through the activation of alkali on halogenated hydrocarbons, the vinyl monomer is subjected to reverse atom transfer radical polymerization, and the reaction rate and product conversion rate are regulated by adjusting the type and amount of alkali to obtain a product with a narrow molecular weight distribution. of polymers.

Specifically include the following steps:

(1) Under the condition of anhydrous and oxygen isolation, mix the vinyl monomer, alkali, catalyst and halogenated hydrocarbon uniformly to form a pre-reaction mixture, and the molar ratio of vinyl monomer to halogenated hydrocarbon is 200:1～ 500:1, the molar ratio of base to catalyst is 0.2:1～4:1;

(2) Place the pre-reaction mixture obtained in step (1) in a reactor filled with protective gas and stir at room temperature for 20 to 30 minutes to fully disperse and dissolve the catalyst and other components in the vinyl monomer, and then place it in Polymerize in a heating device with a predetermined reaction temperature, and adjust the polymerization process by changing the reaction temperature, the type of halogenated hydrocarbon, the type of alkali, the amount of alkali used, and the reaction time;

(3) After the polymerization reaction reaches a predetermined reaction time interval, a certain amount of reaction mixture is taken out from the reactor, and the reaction is stopped by cooling, so as to obtain polymers with different conversion rates;

(4) After removing unreacted vinyl monomer, catalyst and alkali, dry to obtain pure polymer product.

The vinyl monomer is one of methyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate, styrene, vinyl chloride, acrylic acid, acrylamide, acrylonitrile and vinyl acetate;

The halogenated hydrocarbon is ethyl 2-bromophenylacetate, ethyl 2-bromoisobutyrate, methyl 2-bromoisobutyrate, ethyl 2-bromopropionate, 2-bromoethylbenzene, chloroacetic acid One of ethyl ester, 2-chloropropionitrile and 2-bromopropionitrile;

Described base is at least one in inorganic base and organic base, and wherein said inorganic base is sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, sodium phosphate, disodium hydrogen phosphate , sodium dihydrogen phosphate, sodium thiosulfate, ferric hydroxide and basic aluminum oxide, the organic base is potassium methylate, sodium tert-butoxide, potassium tert-butoxide, butyllithium, butyl One of magnesium, butylmagnesium chloride, ethanolamine, ethylenediamine, triethylamine, imidazole and 1,8-diazabicycloundec-7-ene; wherein the catalyst uses iron bromide, bromide One of copper, ferric chloride and ferric chloride hexahydrate.

Preferably, the reaction temperature in step (2) can depend on the type of vinyl monomer, and the range is controlled within the range of general controllable polymerization, 50-120°C; the protective gas in step (2) is an inert gas or one of nitrogen; the reaction time in step (2) depends on the purpose, the reaction kinetics is studied, the time is 3 to 15 hours, and the specific polymer product is prepared, and the time is more than 3 hours.

The following are specific examples:

Example 1:

After the purification of methyl methacrylate monomer, ethyl 2-bromoisobutyrate halogenated hydrocarbon and sodium phosphate, the preparation of polymerization reaction components, methyl methacrylate, ethyl 2-bromoisobutyrate, bromide The molar ratio of iron (high valence transition metal catalyst) to sodium phosphate is 200:1:1:2. The preparation process is as follows: 0.0836 grams of ferric bromide and 0.0928 grams of sodium phosphate are weighed in the glove box and put into an eggplant-shaped bottle, and 6 milliliters of methyl methacrylate monomer is added into the eggplant-shaped bottle, and after magnetic stirring for 20 minutes, Then 37.7 microliters of ethyl 2-bromoisobutyrate was added, and stirring was continued for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction, remove Unreacted monomers, catalysts and bases are calculated for conversion, and the product is dissolved with 2 to 5 milliliters of tetrahydrofuran, and the catalyst is removed through a 200 to 300 mesh neutral alumina column, and dried to obtain a polymethyl methacrylate product.

Example 2:

After purification of methyl methacrylate monomer, ethyl 2-bromophenylacetate, halogenated hydrocarbon, and sodium hydroxide, the polymerization reaction components are prepared, methyl methacrylate, ethyl 2-bromophenylacetate, bromine The molar ratio of ferric oxide (high valence state transition metal catalyst) to sodium hydroxide is 200:1:1:2. The preparation process is: weigh 0.0836 grams of ferric bromide and 0.032 grams of sodium hydroxide in the glove box and put them into an eggplant-shaped bottle, add 6 milliliters of methyl methacrylate monomer into the eggplant-shaped bottle, and stir magnetically for 20 minutes. , and then added 49.5 microliters of ethyl 2-bromophenylacetate, and continued to stir for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C and 90°C respectively; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask for cooling Stop the reaction, remove the unreacted monomer, catalyst and base to calculate the conversion rate, dissolve the product with 2 to 5 milliliters of tetrahydrofuran, remove the catalyst through a 200 to 300 mesh neutral alumina column, and dry to obtain the polymethyl methacrylate product .

Figure 1 shows that the concentration of monomers varies linearly with time (ln[M] ₀ /[M]-t) at different temperatures, indicating that the polymerization reaction under this condition is a first-order kinetic reaction process, and the higher the temperature, the higher the reaction rate faster.

Example 3:

After purification of methyl methacrylate monomer, ethyl 2-bromophenylacetate halogenated hydrocarbon and sodium carbonate, the preparation of polymerization reaction components, methyl methacrylate, ethyl 2-bromophenylacetate, bromide The molar ratio of iron (high valence transition metal catalyst) to sodium carbonate is 200:1:1:4. The preparation process is as follows: in the glove box, 0.0836 grams of ferric bromide and 0.120 grams of sodium carbonate are weighed and put into an eggplant-shaped bottle, and 6 milliliters of methyl methacrylate monomer is added into the eggplant-shaped bottle, and after magnetic stirring for 20 minutes, Then 49.5 microliters of ethyl 2-bromophenylacetate was added, and stirring was continued for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C. After the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction. Calculate the conversion rate of the unreacted monomer, catalyst and alkali, dissolve the product with 2-5 milliliters of tetrahydrofuran, remove the catalyst through a 200-300-mesh neutral alumina column, and dry to obtain the polymethyl methacrylate product.

Figure 2 is the curve of the molecular weight and molecular weight distribution of the polymerization system with the conversion rate at a relatively high alkali content, indicating that the polymerization system has better controllability under this condition.

Example 4:

After purification of methyl methacrylate monomer, ethyl 2-bromophenylacetate halogenated hydrocarbon and potassium hydroxide, the preparation of polymerization reaction components, methyl methacrylate, ethyl 2-bromophenylacetate, bromine The molar ratio of iron oxide (high valence state transition metal catalyst) and potassium hydroxide is 200:1:1:2. The preparation process is as follows: 0.0836 grams of iron bromide and 0.032 grams of potassium hydroxide are weighed in the glove box and put into an eggplant-shaped bottle , add 6 ml of methyl methacrylate monomer into an eggplant-shaped flask, stir magnetically for 20 minutes, then add 49.5 microliters of ethyl 2-bromophenylacetate, and continue stirring for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction, remove Calculate the conversion rate of the unreacted monomer, catalyst and alkali, dissolve the product with 2-5 milliliters of tetrahydrofuran, remove the catalyst through a 200-300-mesh neutral alumina column, and dry to obtain the polymethyl methacrylate product.

Example 5:

After butyl acrylate monomer, benzyl chloride halide and sodium carbonate are purified, carry out polymerization reaction component preparation, butyl acrylate, benzyl chloride, ferric chloride (high valence state transition metal catalyst) and sodium carbonate mol ratio are 200:1:1:2. The preparation process is as follows: weigh 0.0459 grams of ferric chloride and 0.06 grams of sodium carbonate in the glove box and put them into an eggplant-shaped bottle, take 6 milliliters of butyl acrylate monomer and add them to the eggplant-shaped bottle, stir magnetically for 20 minutes, and then add 7.2 microliters of benzyl chloride were stirred for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction, remove Calculate the conversion rate of unreacted monomer, catalyst and alkali, dissolve the product with 2-5 milliliters of tetrahydrofuran, remove the catalyst through a 200-300-mesh neutral alumina column, and dry to obtain a polybutylacrylate product.

Embodiment 6:

After purification of methyl methacrylate monomer, polymethyl methacrylate macromolecular halogenated hydrocarbon, and sodium carbonate, the polymerization reaction components are prepared. Methyl methacrylate, polymethyl methacrylate macromolecular halogenated hydrocarbon , ferric bromide (high valence state transition metal catalyst) and sodium carbonate molar ratio is 500:1:1:2. The preparation process is: take 0.0836 gram of ferric bromide, 0.06 gram of sodium carbonate and 1.5 gram of polymethyl methacrylate macromolecular initiator in the glove box and put it into an eggplant-shaped bottle, and take 6 milliliters of methyl methacrylate monomer Add it into an eggplant-shaped bottle and stir it magnetically for 20 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction, remove Calculate the conversion rate of unreacted monomers, catalysts and alkalis, take samples after a predetermined reaction time interval, dissolve the product with 2 to 5 ml of tetrahydrofuran, remove the catalyst through a 200 to 300 mesh neutral alumina column, and dry to obtain polymethyl Methyl acrylate product.

Embodiment 7:

After purification of acetonitrile, ethyl 2-bromophenylacetate halocarbon and potassium hydroxide, the components for cyclic voltammetry test were prepared. The molar ratio of ethyl 2-bromophenylacetate and potassium hydroxide was 1:2. The preparation process is: take 1.6116 grams of tetrabutylammonium bromide and 0.00675 grams of potassium hydroxide in the glove box and put them into an eggplant-shaped bottle, get 50 milliliters of acetonitrile and 10.5 microliters of ethyl 2-bromophenylacetate In the mouth bottle, magnetically stirred for 20 minutes and then stood still for 2 minutes to obtain a cyclic voltammetry test mixture.

Transfer the mixed liquid in the four-neck bottle to the heating device, control the reaction temperature at 60°C, connect three electrodes, scan at the scanning rate of 0.01V/s, 0.02V/s, and 0.05V/s, and monitor the cyclic voltammetry curve.

Figure 3 is a cyclic voltammetry method to explore whether alkali can activate halogenated hydrocarbons, where a is the cyclic voltammetry curve of ethyl 2-bromophenylacetate, and b is the cycle of ethyl 2-bromophenylacetate after adding potassium hydroxide From the voltammetric curve, it can be seen that the alkali reduces the oxidation-reduction potential of the halogenated hydrocarbon and activates the halogenated hydrocarbon. The ligand-free reverse atom transfer radical polymerization method of the present invention with alkali-activated halogenated hydrocarbons can not use any additional ligands in the reaction process, and the reaction system still has good controllability, but on the other hand, the reaction mechanism cannot The mechanism of the ligand-containing system is used to explain the mechanism. Therefore, the present invention uses computational chemical simulation methods and cyclic voltammetry techniques to explore the reaction mechanism in terms of mechanism research to solve this problem.

Embodiment 8:

After purifying n-butyl methacrylate monomer, ethyl 2-bromophenylacetate halogenated hydrocarbon and sodium carbonate, the polymerization reaction components are prepared, methyl methacrylate, ethyl 2-bromophenylacetate, catalyst (high valence state) and sodium carbonate molar ratio is 200:1:1:2. The preparation process is as follows: Weigh a corresponding amount of high-valent transition metal catalyst and 0.06 gram of sodium carbonate in the glove box and put them into an eggplant-shaped bottle, add 8 milliliters of n-butyl methacrylate monomer into the eggplant-shaped bottle, and magnetically stir After 20 minutes, 49.5 microliters of ethyl 2-bromophenylacetate was added, and stirring was continued for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction, remove The unreacted monomer, catalyst and alkali are used to calculate the conversion rate, and the product is dissolved with 2-5 milliliters of tetrahydrofuran, and the catalyst is removed through a 200-300-mesh neutral alumina column, and dried to obtain a poly-n-butyl methacrylate product.

Embodiment 9:

After the purification of methyl methacrylate monomer, ethyl 2-bromoisobutyrate halogenated hydrocarbon and sodium phosphate, the preparation of polymerization reaction components, methyl methacrylate, ethyl 2-bromoisobutyrate, bromide The molar ratio of iron (high valence transition metal catalyst) to sodium phosphate is 400:1:1:0.2. The preparation process is as follows: in the glove box, 0.0836 grams of ferric bromide and 0.0093 grams of sodium phosphate are weighed and put into an eggplant-shaped bottle, and 12 milliliters of methyl methacrylate monomer is added into the eggplant-shaped bottle, and after magnetic stirring for 20 minutes, Then 37.7 microliters of ethyl 2-bromoisobutyrate was added, and stirring was continued for 2 minutes to obtain a pre-reaction mixture.

Transfer the pre-reaction mixture in the eggplant-shaped bottle to the heating device, and control the reaction temperature to 60°C; after the polymerization reaction reaches the predetermined reaction time interval, take a certain amount of the mixture from the reactor and pour it into the flask to cool to stop the reaction, remove Unreacted monomers, catalysts and bases are calculated for conversion, and the product is dissolved with 2 to 5 milliliters of tetrahydrofuran, and the catalyst is removed through a 200 to 300 mesh neutral alumina column, and dried to obtain a polymethyl methacrylate product.

By changing the type of catalyst to adjust the polymerization rate and controllability, using ferric bromide, ferric chloride, copper bromide, and ferric chloride hexahydrate as catalysts, the preparation of the aforementioned pre-reaction mixture and ligand-free The polymerization reaction process; by changing the type and amount of alkali to adjust the polymerization rate and controllability, using inorganic bases: sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, thio Sodium sulfate, ferric hydroxide and basic aluminum oxide, and organic bases potassium methoxide, sodium tert-butoxide, potassium tert-butoxide, butyllithium, butylmagnesium, butylmagnesium chloride, ethanolamine, ethylenediamine, triethyl Amine, imidazole and 1,8-diazabicycloundec-7-ene repeat the preparation of the aforementioned pre-reaction mixture and the ligand-free polymerization process to obtain the corresponding vinyl monomer polymer.

In addition to the specific monomer types in the above examples, the applicable monomer types in the present invention can also be methyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate, styrene, vinyl chloride, acrylic acid, Any one of acrylamide, acrylonitrile and vinyl acetate; the polymerization reaction can be a homopolymerization reaction in which a monomer participates, or a copolymerization reaction in which multiple monomers participate; corresponding halogenated hydrocarbons, catalysts, It can be flexibly adjusted according to the specific monomer type.

In addition to the specific reaction temperature and time used in the atom transfer radical polymerization reaction in the above examples, the reaction temperature and reaction time can be adjusted flexibly; the reaction temperature depends on the type of monomer, and the range is controlled within the range of general controllable polymerization , such as 50-120°C; the reaction time depends on the purpose, and the reaction time is 3-15 hours to study the reaction kinetics. To prepare a specific polymer product, the reaction time is more than 3 hours.

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (9)

1. a reverse atom transfer radical polymerization method of alkali activation halohydrocarbon effect, it is characterized in that, this polymerization method does not use organic ligand and free radical initiator, polymerization system comprises vinyl monomer, halohydrocarbon, A base and a high-valence state transition metal catalyst, through the activation of the base on the halogenated hydrocarbon, the vinyl monomer is subjected to a reverse atom transfer radical polymerization reaction to form a polymer with a narrow molecular weight distribution. 2. the reverse atom transfer radical polymerization method of alkali activation halogenated hydrocarbon effect as claimed in claim 1, is characterized in that, specifically comprises the following steps: (1) Under the condition of anhydrous and oxygen isolation, uniformly mix the vinyl monomer, alkali, high-valence transition metal catalyst and halogenated hydrocarbon to form a pre-reaction mixture; Wherein, the molar ratio of the vinyl monomer to the high-valent state transition metal catalyst is 200:1-500:1; the molar ratio of the vinyl monomer to the halogenated hydrocarbon is 200:1-500:1; The molar ratio of the base to the high-valence transition metal catalyst is 0.2:1 to 4:1; (2) Putting the pre-reaction mixture in step (1) at a predetermined reaction temperature to react, and the vinyl monomer starts to undergo reverse atom transfer radical polymerization to generate a polymer with a narrow molecular weight distribution. 3. The reverse atom transfer radical polymerization method of alkali-activated halogenated hydrocarbons as claimed in claim 1, wherein the reaction radical initiator is an azo initiator or a peroxide initiator. 4. as claimed in claim 1 or 2, the reverse atom transfer radical polymerization method of the alkali-activated halogenated hydrocarbon effect is characterized in that, the vinyl monomer is methyl methacrylate, butyl methacrylate, acrylic acid At least one of methyl ester, butyl acrylate, styrene, vinyl chloride, acrylic acid, acrylamide, acrylonitrile and vinyl acetate; The halogenated hydrocarbon is ethyl 2-bromophenylacetate, ethyl 2-bromoisobutyrate, methyl 2-bromoisobutyrate, ethyl 2-bromopropionate, 2-bromoethylbenzene, chloroacetic acid Any one of ethyl ester, 2-chloropropionitrile and 2-bromopropionitrile; Described base is at least one in inorganic base or organic base, and wherein said inorganic base is sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, sodium phosphate, disodium hydrogen phosphate , at least one of sodium dihydrogen phosphate, sodium thiosulfate, iron hydroxide and basic aluminum oxide; the organic base is potassium methylate, sodium tert-butoxide, potassium tert-butoxide, butyllithium, butyl At least one of base magnesium, butyl magnesium chloride, ethanolamine, ethylenediamine, triethylamine, imidazole and 1,8-diazabicycloundec-7-ene; The high-valence transition metal catalyst is a high-valence metal halide, preferably at least one of ferric bromide, copper bromide, ferric chloride and ferric chloride hexahydrate. 5. as claimed in claim 2, the reverse atom transfer radical polymerization method of alkali-activated halohydrocarbon effect is characterized in that, the pre-reaction mixed solution described in step (1) is stirred and mixed under the atmosphere of protective gas for 20～ obtained in 30 minutes; preferably, the protective gas is nitrogen or an inert gas. 6 . The reverse atom transfer radical polymerization method of alkali-activated halogenated hydrocarbons according to claim 2 , wherein the predetermined reaction temperature in step (2) is 50° C. to 120° C. 7. the reverse atom transfer radical polymerization method of alkali activation halogenated hydrocarbon as claimed in claim 2, is characterized in that, the reverse atom transfer radical polymerization reaction time described in step (2) is not less than 3 hours; Preferably Preferably, the reverse atom transfer radical polymerization reaction time is 3 to 15 hours. 8. the reverse atom transfer radical polymerization method of alkali activation halogenated hydrocarbon effect as claimed in claim 2, is characterized in that, the reverse atom transfer radical polymerization reaction of described alkali activation halogenated hydrocarbon effect is by cooling reaction system In the end, the generated polymer with narrow molecular weight distribution is purified by removing catalyst, base and unreacted vinyl monomer in the reaction system. 9. The reverse atom transfer radical polymerization method of alkali-activated halogenated hydrocarbons as claimed in claim 2, characterized in that the molecular weight distribution index of the narrow molecular weight distribution polymer in step (2) is 1.07-1.25.