Hydrogen-activated atom transfer radical polymerization method
By adding a hydrogen dissociation catalyst and introducing hydrogen gas into the ATRP reaction system, the problem of decreased reaction rate caused by the accumulation of divalent copper was solved, achieving simple and efficient reaction rate control, simplifying the operation and avoiding the introduction of impurities.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUNAN UNIV
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-19
AI Technical Summary
In existing ATRP technology, the accumulation of divalent copper leads to a decrease in the reaction rate. Existing reduction methods are complex or introduce impurities, and there is a lack of simple and effective control methods.
A hydrogen dissociation catalyst is added to the ATRP reaction system, and hydrogen gas or a mixture of hydrogen and inert gas is introduced. The hydrogen gas is used to activate the catalyst to generate electrons to reduce CuⅡX to CuⅠX, thereby realizing the polymerization reaction. The reaction rate is controlled by adjusting the hydrogen gas concentration.
It simplifies the polymerization reaction operation, and allows for flexible control of the reaction rate by adjusting the hydrogen concentration, avoiding complex equipment and the introduction of impurities.
Smart Images
Figure CN122060101A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymerization technology, specifically relating to a method for hydrogen-activated atom transfer radical polymerization. Background Technology
[0002] Atom transfer radical polymerization (ATRP) is an important controlled radical polymerization method, highly regarded for its excellent molecular weight control, precise sequence structure design, and good applicability. The ATRP system initiates polymerization by generating free radicals through the reaction of a monovalent copper catalyst with an alkyl halide initiator. The reaction rate and product distribution are closely related to the valence state distribution of the copper catalyst in the system. Due to the continuous free radical effect, divalent copper gradually accumulates during the reaction, causing a decrease in the polymerization rate or even cessation of the reaction. Existing ATRP technologies generally reduce divalent copper to monovalent copper by adding chemical reducing agents such as vitamin C or stannous octoate, or by using external fields such as light, electricity, or ultrasound. However, adding chemical reducing agents introduces additional impurities, while physical reduction methods such as light and electricity require complex experimental setups and procedures. Summary of the Invention
[0003] To address the aforementioned technical problems, the present invention aims to provide a method for hydrogen-activated atom transfer radical polymerization. This method is simple to operate, and the polymerization reaction can be initiated simply by introducing hydrogen gas. Furthermore, the polymerization rate can be controlled by changing the concentration of the introduced hydrogen gas, providing a new approach for the regulation of the atom transfer radical polymerization process.
[0004] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: A method for hydrogen-activated atom transfer radical polymerization involves adding a hydrogen dissociation catalyst to an existing atom transfer radical polymerization reaction system, and then introducing a hydrogen / inert gas mixture or pure hydrogen to carry out the polymerization reaction, thereby obtaining the polymer.
[0005] In this invention, the existing atom transfer radical polymerization reaction system is a conventional reaction system, including a monomer, an initiator, a catalyst, a ligand, and a solvent. The monomer is selected from methyl acrylate, butyl acrylate, methyl methacrylate, styrene, acrylonitrile, and acrylamide; the initiator is selected from ethyl 2-bromoisobutyrate, methyl 2-bromopropionate, and (1-bromoethyl)benzene; the catalyst is selected from copper chloride, ferric chloride, copper bromide, and ferric bromide; the ligand is selected from tris(2-(dimethylamino)ethyl)amine, bipyridine, or tris(2-pyridinemethyl)amine; and the solvent is selected from acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide. The molar ratio of the monomer, initiator, catalyst, and ligand is 2000~200000:25~200:1:2~10.
[0006] Furthermore, the hydrogen dissociation catalyst is one of Pt / TiO2, Pd / TiO2, Pt / WO3, or Pt / MoO3. In this invention, the hydrogen dissociation catalyst can be prepared using existing conventional methods, such as impregnation reduction, which will not be elaborated upon here.
[0007] Furthermore, in the hydrogen dissociation catalyst, the loading of Pt or Pd is 0.2~2 wt.%.
[0008] Furthermore, by mass ratio, the amount of hydrogen dissociation catalyst added is 5 to 20 times that of the catalyst in existing atom transfer radical polymerization reaction systems.
[0009] Furthermore, the inert gas is selected from argon, helium, and nitrogen.
[0010] The beneficial effects of this invention are: This invention ingeniously utilizes the hydrogen dissociation of hydrogen gas on a hydrogen dissociation catalyst to generate electrons, thereby converting Cu... Ⅱ X / L is reduced to Cu Ⅰ / L, to initiate an atom transfer radical polymerization reaction. This method is simple to operate, and the polymerization reaction can be initiated simply by blowing in hydrogen gas. Moreover, the polymerization rate can be controlled by changing the concentration of hydrogen gas introduced, providing a new approach to the control of the atom transfer radical polymerization process. Attached Figure Description
[0011] Figure 1 The image shows the XRD pattern of Pt / TiO2 (2wt.%) prepared in Example 1.
[0012] Figure 2 The image shows a SEM image of Pt / TiO2 (2wt.%) prepared in Example 1.
[0013] Figure 3 The elemental distribution diagram of Pt / TiO2 (2wt.%) prepared in Example 1 is shown.
[0014] Figure 4 This is a graph showing the changes in GPC polymer products at different conversion rates in Example 1.
[0015] Figure 5 The figure shows the polymerization reaction kinetics curve for Example 1.
[0016] Figure 6 The graph shows the change in molecular weight and molecular weight distribution as a function of conversion rate for Example 1. Detailed Implementation
[0017] The present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited to these embodiments.
[0018] Example 1
[0019] (1) Preparation of Pt / TiO2 (2wt.%): Weigh 0.300g of carrier TiO2, add it to 60 mL of deionized water, and ultrasonically disperse for 20 min to obtain solution A; Weigh 9.81 mg of platinum nitrate, dissolve it in 6 mL of deionized water, add it dropwise to solution A, and stir for 30 min to obtain solution B; Weigh 0.454g of sodium borohydride, dissolve it in 6 mL of deionized water, add it dropwise to solution B, and continue stirring for 5 min to obtain solution C; After standing for 30 min, solution C is filtered, washed three times with water to obtain Pt / TiO2 (2wt.%), vacuum dried for 12 h, and then sealed and stored.
[0020] (2) Hydrogen-activated atom transfer radical polymerization: Methyl acrylate (2.0 mL, 22.2 mmol), acetonitrile (1.5 mL), CuBr2 (0.5 mg), tris(2-dimethylaminoethyl)amine (6 μL, 0.02 mmol), ethyl 2-bromoisobutyrate (32 μL, 0.22 mmol), and Pt / TiO2 (2 wt.%) nanoparticles (8 mg) were added to a 25 mL reaction tube, sealed with a rubber stopper, and placed in a 40 °C water bath. Ar was introduced to remove oxygen, and after 10 min, 20% H2 / Ar (8 mL / min) was bubbled in, and the reaction began under magnetic stirring. Samples were taken with a needle at intervals for analysis. After 30 min of reaction, the conversion rate was 82%, and the apparent reaction rate was 3.98 h. -1 The molecular weight of the polymer product is 8000 g / mol (the theoretical molecular weight is 7300 g / mol), and the molecular weight distribution is 1.13.
[0021] Example 2
[0022] (1) The preparation of Pt / TiO2 (2wt.%) was carried out in the same manner as in Example 1.
[0023] (2) Hydrogen-activated atom transfer radical polymerization: Methyl acrylate (2.0 mL, 22.2 mmol), acetonitrile (1.5 mL), CuBr2 (0.5 mg), tris(2-dimethylaminoethyl)amine (6 μL, 0.02 mmol), ethyl 2-bromoisobutyrate (32 μL, 0.22 mmol), and Pt / TiO2 (2 wt.%) nanoparticles (8 mg) were added to a 25 mL reaction tube and placed in a 40 °C water bath. Under open conditions, without Ar deoxygenation, 20% H2 / Ar (8 mL / min) was directly bubbled in, and the reaction was started under magnetic stirring. Samples were taken with a needle at intervals for analysis. After 30 min of reaction, the conversion rate was 84%, and the apparent reaction rate was 3.69 h. -1The molecular weight of the polymer product is 7300 g / mol (the theoretical molecular weight is 7400 g / mol), and the molecular weight distribution is 1.18.
[0024] Example 3
[0025] (1) The preparation of Pt / WO3 (2wt.%) is carried out in the same manner as in Example 1, except that the amount of WO3 added is 0.300g.
[0026] (2) The steps for hydrogen-controlled atom transfer radical polymerization are the same as in Example 1. After 3 hours of reaction, the conversion rate was 66%, and the apparent reaction rate was 0.36 h. -1 The molecular weight of the polymer product is 5800 g / mol (the theoretical molecular weight is 4300 g / mol), and the molecular weight distribution is 1.20.
[0027] Example 4
[0028] (1) The preparation of Pt / TiO2 (0.5wt.%) was carried out in the same manner as in Example 1, except that the amount of platinum nitrate added was 2.46.
[0029] (2) The procedure for hydrogen-controlled atom transfer radical polymerization is the same as in Example 1. After 30 min of reaction, the conversion rate was 41%, and the apparent reaction rate was 1.31 h. -1 The molecular weight of the polymer product is 3600 g / mol (the theoretical molecular weight is 3700 g / mol), and the molecular weight distribution is 1.27.
[0030] Example 5
[0031] (1) The preparation of Pt / TiO2 (1wt.%) was carried out in the same manner as in Example 1, except that the amount of platinum nitrate added was 4.92.
[0032] (2) The procedure for hydrogen-controlled atom transfer radical polymerization is the same as in Example 1. After 30 min of reaction, the conversion rate was 73%, and the apparent reaction rate was 3.07 h. -1 The molecular weight of the polymer product is 7400 g / mol (the theoretical molecular weight is 6500 g / mol), and the molecular weight distribution is 1.15.
[0033] Example 6
[0034] (1) The preparation of Pt / TiO2 (2wt.%) was carried out in the same manner as in Example 1.
[0035] (2) Except for the different hydrogen concentration, the steps for hydrogen-controlled atom transfer radical polymerization are the same as in Example 1, wherein the hydrogen concentration is 3.8% H2 / Ar.
[0036] After 30 min of reaction, the conversion rate was 31%, and the apparent reaction rate was 0.89 h⁻¹. -1 The molecular weight of the polymer product is 4600 g / mol (the theoretical molecular weight is 3300 g / mol), and the molecular weight distribution is 1.24.
[0037] Example 7
[0038] (1) The preparation of Pt / TiO2 (2wt.%) was carried out in the same manner as in Example 1.
[0039] (2) Except for the different hydrogen concentration, the steps for hydrogen-controlled atom transfer radical polymerization are the same as in Example 1, wherein the hydrogen concentration is 10% H2 / Ar.
[0040] After 30 min of reaction, the conversion rate was 64%, and the apparent reaction rate was 2.37 h. -1 The molecular weight of the polymer product is 5600 g / mol (the theoretical molecular weight is 5700 g / mol), and the molecular weight distribution is 1.13.
[0041] Comparative Example 1 Same as Example 1, except that no hydrogen dissociation catalyst is added, so the polymerization reaction cannot take place.
[0042] Comparative Example 2 Same as Example 1, except that the added hydrogen dissociation catalyst was replaced with 8 mg Pt, and the polymerization reaction could not be carried out.
[0043] Comparative Example 3 Same as Example 1, except that the added hydrogen dissociation catalyst was replaced with 8 mg TiO2 (anatase, 2-3 nm), which prevented the polymerization reaction from taking place.
[0044] Comparative Example 4 Same as Example 1, except that H2 / Ar is not introduced, only pure Ar (8 mL / min) is introduced, and the polymerization reaction cannot proceed.
Claims
1. A method for hydrogen-activated atom transfer radical polymerization, characterized in that: Adding a hydrogen dissociation catalyst to an existing atom transfer radical polymerization system and then introducing a hydrogen / inert gas mixture or pure hydrogen gas to carry out the polymerization reaction yields the polymer.
2. The method according to claim 1, characterized in that: Existing atom transfer radical polymerization reaction systems include monomers, initiators, catalysts, ligands, and solvents.
3. The method according to claim 2, characterized in that: The polymerizable monomer may be selected from one of methyl acrylate, butyl acrylate, methyl methacrylate, styrene, acrylonitrile, and acrylamide; The initiator is one of ethyl 2-bromoisobutyrate, methyl 2-bromopropionate, and (1-bromoethyl)benzene; The catalyst is selected from one of copper chloride, ferric chloride, copper bromide, and ferric bromide; The ligand is selected from one of tris(2-(dimethylamino)ethyl)amine, bipyridine, or tris(2-pyridinemethyl)amine; The solvent is selected from acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide.
4. The method according to claim 2, characterized in that: The molar ratio of the polymerizing monomer, initiator, catalyst and ligand is 2000~200000:25~200:1:2~10.
5. The method according to any one of claims 2-4, characterized in that: The hydrogen dissociation catalyst is one of Pt / TiO2, Pd / TiO2, Pt / WO3 or Pt / MoO3.
6. The method according to claim 5, characterized in that: In the hydrogen dissociation catalyst, the loading of Pt or Pd is 0.2~2 wt.%.
7. The method according to claim 5, characterized in that: The amount of hydrogen dissociation catalyst added is 5 to 20 times that of the catalyst in existing atom transfer radical polymerization reaction systems, based on the mass ratio.
8. The method according to any one of claims 2-4, characterized in that: The inert gas is selected from argon, helium, and nitrogen.