Use of long alkyl amide side chain triphenylamine compounds in metal-free organic photocatalytic atom transfer radical polymerization

Abstract

The application belongs to the technical field of organic photocatalysts, and provides application of a long-alkyl amide side chain triphenylamine compound in metal-free organic photocatalytic atom transfer radical polymerization. The long-alkyl amide side chain triphenylamine compound has long fluorescent radiation life and phosphorescent radiation life, and can maintain high initiation efficiency in the initial stage of low-viscosity polymerization and the later stage of high-viscosity polymerization; meanwhile, the long-alkyl amide side chain triphenylamine compound can form a cationic radical species by electron transfer with a halogenated initiator under an excited state, and the cationic radical species has a long life, and meanwhile, the cationic radical species can further absorb photons to form a radical cationic excited state to complete a catalytic cycle, so that the long-alkyl amide side chain triphenylamine compound has a fast chain deactivation rate, and the polymerization time is further shortened and the polymerization controllability is further improved.

Description

Technical Field

[0001] This invention relates to the field of organic photocatalyst technology, and in particular to the application of a long alkylamide side-chain triphenylamine compound in metal-free organophotocatalytic atom transfer radical polymerization. Background Technology

[0002] Metal-free organophotocatalytic atom transfer radical polymerization (O-ATRP) is a novel atom transfer radical polymerization method that uses organic photocatalysts to replace traditional metal catalysts. Due to its precise molecular weight control, narrow molecular weight distribution (low PDI), and excellent functional group compatibility, it has been widely used in electronics, biology, and other fields in recent years. Its advantages include: 1) Spatiotemporally controllable light source irradiation allows for precise control of the relative molecular mass and molecular weight distribution of the polymer; 2) Compared with traditional transition metal catalysts such as copper, iridium, and platinum, organic photocatalysts are environmentally friendly and inexpensive; 3) The resulting polymer products are free of metal ion residues, which is beneficial for applications in the semiconductor and biological fields.

[0003] The reaction mechanism of metal-free organophotocatalytic atom transfer radical polymerization (O-ATRP) involves the following steps: During the initiation stage, the organic photocatalyst in the system is irradiated with a suitable light source. The organic photocatalyst absorbs the light and becomes excited, and its excited-state species can catalyze the polymerization reaction through two pathways. Pathway 1: The excited-state organic photocatalyst can directly undergo a redox reaction with the organohalide initiator, acquiring halogen atoms from the initiator to generate an active intermediate radical (R·) and an organic photocatalyst cation. The radical (R·) initiates monomer polymerization to generate the active species RM·, which then acquires halogen atoms X from the organohalide to generate a dormant species RMX. The organic photocatalyst cation accepts electrons from the electron donor in the system and returns to the ground state, completing the photocatalytic cycle. Pathway 2: The excited-state organic photocatalyst first acquires electrons from the electron donor in the system to generate anionic radicals, which then undergo redox reactions with the organohalide initiator and subsequent reactions, losing electrons and returning to the ground state to complete the photocatalytic cycle. From the polymerization process, the organic photocatalyst constitutes the smallest proportion in the O-ATRP system, yet it is a crucial component.

[0004] Currently reported organic photocatalysts commonly used in O-ATRP polymerization systems mainly fall into four categories: the first category includes fused-ring compounds such as pyrene, perylene, and benzothiadiazole; the second category includes phenothiazine, dihydrophenazine, and phenoxazine derivatives; the third category consists of carbazole derivatives; and the fourth category comprises organic dyes such as eosin Y, erythrosine B, and rhodamine. These four categories of organic photocatalysts still have some shortcomings, such as: 1) the excited states formed by absorbing visible light rarely possess both long fluorescence and phosphorescence lifetimes, resulting in low initiation efficiency in the early stages of low-viscosity polymerization and in the later stages of high-viscosity polymerization; 2) the electron transfer between excited-state molecules and organic halogenated compounds results in short-lived cationic radical species, leading to slow chain deactivation rates and reduced polymerization controllability. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide an application of a long alkylamide side-chain triphenylamine compound in metal-free organophotocatalytic atom transfer radical polymerization. The long alkylamide side-chain triphenylamine compound of this invention possesses both long fluorescence and phosphorescence lifetimes, maintaining high initiation efficiency in both the early stages of low-viscosity polymerization and the later stages of high-viscosity polymerization. Simultaneously, the cationic radical species formed by the long alkylamide side-chain triphenylamine compound undergoing electron transfer with a halogenated initiator in the excited state have long lifetimes. Furthermore, the cationic radicals can further absorb photons to form excited radical cations, completing the catalytic cycle, thereby exhibiting a rapid chain deactivation rate, further shortening polymerization time and improving polymerization controllability.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides the application of a long alkylamide side-chain triphenylamine compound as an organic photocatalyst in metal-free organophotocatalytic atom transfer radical polymerization, wherein the long alkylamide side-chain triphenylamine compound is one or more compounds with structures shown in Formulas 1 to 15:

[0008] Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8 Formula 9 Formula 10 Formula 11 Formula 12 Formula 13 Formula 14 Formula 15.

[0009] This invention also provides a metal-free organic photocatalytic atom transfer radical polymerization system, comprising an organic photocatalyst, an organic halide initiator, and a functional polymerization monomer, wherein the organic photocatalyst is a triphenylamine compound with a long alkylamide side chain, and the triphenylamine compound with the long alkylamide side chain is one or more compounds with structures shown in Formulas 1 to 15.

[0010] Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8 Formula 9 Formula 10 Formula 11 Formula 12 Formula 13 Formula 14 Formula 15.

[0011] Preferably, based on the total molar percentage of the organic photocatalyst, the organic halide initiator, and the functional polymer monomer as 100%, the molar percentage of the organic photocatalyst is 0.0001~8%, the molar percentage of the functional polymer monomer is 82~98.9999%, and the molar percentage of the organic halide initiator is 1~10%.

[0012] Preferably, the functional polymeric monomer is a monomer having vinyl unsaturated groups.

[0013] Preferably, the functional polymeric monomer includes one or more of acrylate monomers, styrene monomers, maleimide monomers, and borneol monomers.

[0014] Preferably, the organohalogen initiator includes organochlorides and / or organobromines.

[0015] Preferably, the metal-free organophotocatalytic atom transfer radical polymerization system further includes a solvent.

[0016] Preferably, the solvent includes one or more of benzene, toluene, anisole, chlorobenzene, dichlorobenzene, tetrahydrofuran, 1,4-dioxane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile.

[0017] The present invention also provides a polymerization reaction comprising the following steps:

[0018] The polymerization system undergoes a polymerization reaction under the illumination of a light source;

[0019] The polymerization system is the metal-free organic photocatalytic atom transfer radical polymerization system described in the above technical solution.

[0020] Preferably, the light source is a light source with a wavelength of 410nm, a light source with a wavelength of 450nm, or a white LED light source; the power of the light source is 5~20mW / cm². 2 ;

[0021] The polymerization reaction is carried out at a temperature of 20-40°C for 8-18 hours.

[0022] This invention provides the application of a long alkylamide side-chain triphenylamine compound as an organic photocatalyst in metal-free organophotocatalytic atom transfer radical polymerization. The long alkylamide side-chain triphenylamine compound is one or more compounds with structures shown in Formulas 1 to 15. First, the long alkylamide side-chain triphenylamine compound of this invention can be matched with safe and environmentally friendly LED light sources. Second, the long alkylamide side-chain triphenylamine compound provided by this invention possesses both long fluorescence and phosphorescence lifetimes, maintaining high initiation efficiency in both the early stages of low-viscosity polymerization and the later stages of high-viscosity polymerization. Third, the long alkylamide side-chain triphenylamine compound provided by this invention can undergo electron transfer with a halogenated initiator in the excited state, forming a long-lived cationic radical species. This cationic radical species can further absorb photons to form a radical cation excited state, completing the catalytic cycle, thereby exhibiting a rapid chain deactivation rate, further shortening the polymerization time and improving polymerization controllability. After electron transfer, the halogen atom of the halogenated initiator is captured, forming an intermediate radical (R·), which initiates monomer polymerization. Attached Figure Description

[0023] Figure 1 The absorption spectra of the organic photocatalyst A7 neutral molecule (left) and its cation (right). Detailed Implementation

[0024] This invention provides the application of a long alkylamide side-chain triphenylamine compound as an organic photocatalyst in metal-free organophotocatalytic atom transfer radical polymerization, wherein the long alkylamide side-chain triphenylamine compound is one or more compounds with structures shown in Formulas 1 to 15:

[0025] Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8 Formula 9 Formula 10 Formula 11 Formula 12 Formula 13 Formula 14 Formula 15.

[0026] In this invention, the long alkylamide side-chain triphenylamine compound is preferably used as an organic photocatalyst when applied to metal-free organophotocatalytic atom transfer radical polymerization.

[0027] This invention also provides a metal-free organic photocatalytic atom transfer radical polymerization system, comprising an organic photocatalyst, an organic halide initiator, and a functional polymerization monomer, wherein the organic photocatalyst is a triphenylamine compound with a long alkylamide side chain, and the triphenylamine compound with the long alkylamide side chain is one or more compounds with structures shown in Formulas 1 to 15.

[0028] Formula 1 (denoted as A1) Equation 2 (denoted as A2) Equation 3 (denoted as A3) Equation 4 (denoted as A4) Formula 5 (denoted as A5) Equation 6 (denoted as A6) Equation 7 (denoted as A7) Formula 8 (denoted as A8) Equation 9 (denoted as A9) Formula 10 (denoted as A10) Formula 11 (denoted as A11) Equation 12 (denoted as A12) Equation 13 (denoted as A13) Equation 14 (denoted as A14) Formula 15 (denoted as A15).

[0029] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0030] The metal-free organic photocatalytic atom transfer radical polymerization system provided by this invention comprises an organic photocatalyst, an organic halide initiator, and a functional polymerizable monomer. In this invention, based on the total molar percentage of the organic photocatalyst, organic halide initiator, and functional polymerizable monomer as 100%, the molar percentage of the organic photocatalyst is preferably 0.0001~8%, more preferably 0.001~5%, more preferably 0.01~2%, and specifically preferably 0.01%, 0.02%, 0.05%, 0.15%, 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%; the functional... The molar percentage content of the polymeric monomer is preferably 82-98.9999%, more preferably 87-97%, and even more preferably 91-96%, specifically preferably 91%, 92%, 93%, 93.5%, 93.8%, 94%, 94.2%, 94.5%, 94.8%, 94.85%, 94.9%, 94.95%, 95%, or 96%; the molar percentage content of the organohalide initiator is preferably 1-10%, more preferably 2-8%, and even more preferably 3-7%, specifically preferably 5%.

[0031] In this invention, the organic photocatalyst is a long alkylamide side-chain triphenylamine compound, which is one or more compounds with structures shown in Formulas 1 to 15. This invention does not have special requirements regarding the source of the long alkylamide side-chain triphenylamine compound with structures shown in Formulas 1 to 15; it can be prepared using conventional preparation methods well known to those skilled in the art or by purchasing commercially available products.

[0032] In this invention, the functional polymeric monomer is preferably a monomer having a vinyl unsaturated group. In this invention, the functional polymeric monomer preferably includes one or more of acrylate monomers, styrene monomers, maleimide monomers, and borneolene monomers. In this invention, the acrylate monomer preferably includes one or more of methacrylate, 2-methyl-2-adamantyl methacrylate, and tert-butyl methacrylate. In this invention, the styrene monomer preferably includes 4-hydroxystyrene. In this invention, the maleimide monomer preferably includes maleic anhydride. In this invention, the borneolene monomer preferably includes 5-norborneol-2-carboxylic acid tert-butyl ester.

[0033] In this invention, the organohalide initiator comprises organochlorides and / or organobromines, more preferably organobromines. In this invention, the organobromine preferably comprises diethyl 2-bromo-2-methylmalonate, ethyl 2-bromopropionate, or a bromine-containing polymer; the bromine-containing polymer is preferably a polymer obtained from the metal-free organophotocatalytic atom transfer radical polymerization system provided by this invention, specifically, the bromine-containing polymer preferably has the structure shown in Formula A or Formula B:

[0034] Formula A, Formula B.

[0035] In this invention, in formulas A and B, n is a natural number, and the values ​​of n can be the same or different; m is a natural number, and the values ​​of m can be the same or different. In this invention, in formulas A and B, the value of n is independently 40 to 160. In this invention, the value of m in formula B is 40 to 120. In this invention, the weight-average molecular weight of formula A is preferably 10,000 to 17,000. In this invention, the weight-average molecular weight of formula B is preferably 20,000 to 40,000, more preferably 24,000 to 36,000.

[0036] In this invention, R in formula A or formula B is or .

[0037] In this invention, Formula A is preferably a polymer obtained from the polymerization system provided in Example 1 of this application; Formula B is preferably a polymer obtained from the polymerization system provided in Example 2 of this application.

[0038] In this invention, the metal-free organophotocatalytic atom transfer radical polymerization system further includes a solvent. Preferably, the solvent comprises one or more of benzene, toluene, xylene, anisole, chlorobenzene, dichlorobenzene, tetrahydrofuran (THF), 1,4-dioxane, anisole, N-methylpyrrolidone, dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile. More preferably, it comprises one or two of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, tetrahydrofuran, 1,4-dioxane, anisole, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile. More preferably, it comprises one or more of tetrahydrofuran (THF), 1,4-dioxane, anisole, and dimethylformamide (DMF). In this invention, when the solvent is preferably two of the above-mentioned solvent types, the volume ratio of any two solvents is preferably 1:1 and 3:1. This invention does not have special requirements for the solvent content in the metal-free organophotocatalytic atom transfer radical polymerization system, as long as the polymerization reaction proceeds smoothly.

[0039] The present invention also provides a polymerization reaction comprising the following steps:

[0040] The polymerization system undergoes a polymerization reaction under the illumination of a light source;

[0041] The polymerization system is the metal-free organic photocatalytic atom transfer radical polymerization system described in the above technical solution.

[0042] In this invention, the light source is preferably a light source with a wavelength of 410 nm, a light source with a wavelength of 450 nm, or a white LED light source. In this invention, organic photocatalyst A7 is used as an example. Figure 1 The absorption spectra of the neutral molecule (left) and its cation (right) of organic photocatalyst A7 are shown below. Figure 1 It can be seen that the neutral molecules of organic photocatalyst A7 absorb at 410 nm, which is compatible with the short-wavelength band of white light; while the cations not only absorb at 410 nm, which is compatible with the short-wavelength band of white light, but also with the long-wavelength band of white light.

[0043] In this invention, the power of the light source is preferably 5~20mW / cm². 2 Specifically, the preferred value is 5mW / cm 2 8mW / cm 2 9mW / cm 2 10mW / cm 2 12mW / cm 2 13mW / cm2 14mW / cm 2 15mW / cm 2 16mW / cm 2 17mW / cm 2 18mW / cm 2 Or 20mW / cm 2 .

[0044] In this invention, the temperature of the polymerization reaction is preferably 20~40℃, specifically 20℃, 25℃, 30℃, 35℃ or 40℃; the time is preferably 8~18h, specifically 8h, 10h, 12h, 14h, 16h or 18h.

[0045] In this invention, the polymerization reaction is preferably carried out under oxygen-free and anhydrous conditions.

[0046] After the polymerization reaction is completed, the present invention preferably further includes: adding methanol to the obtained polymerization reaction system to precipitate the polymer, separating the solid and liquid phases to obtain a crude polymer product; washing the crude polymer product to obtain a pure polymer product. In the present invention, the solid-liquid separation is preferably performed by suction filtration, and the suction filtration is preferably carried out using a Buchner funnel. In the present invention, the solvent used for washing is preferably methanol.

[0047] The following examples illustrate the application of the long alkylamide side-chain triphenylamine compound provided by the present invention in metal-free organophotocatalytic atom transfer radical polymerization. However, these examples should not be construed as limiting the scope of protection of the present invention.

[0048] Example 1

[0049] Experimental studies were conducted on the O-ATRP polymerization of the above 15 long alkylamide side-chain triphenylamine compounds as organic photocatalysts.

[0050] In the O-ATRP polymerization system, based on the total molar percentage of functional monomers, organohalide initiators, and organic photocatalysts as 100%, the O-ATRP polymerization system includes the following components in molar percentage:

[0051] Functional polymer monomers: 87-94.9999%;

[0052] 5% organic halide initiator;

[0053] Organic photocatalyst 0.0001~8%.

[0054] The functional polymer monomer is any one of methacrylate, 2-methyl-2-adamantyl methacrylate, maleic anhydride, 4-hydroxystyrene, and 5-norbornene-2-carboxylic acid tert-butyl ester.

[0055] The organic photocatalyst is one of the 15 long alkylamide side-chain triphenylamine compounds mentioned above.

[0056] The organohalogen initiator is diethyl 2-bromo-2-methylmalonate and / or ethyl 2-bromopropionate.

[0057] Add 1 mL of THF, Dioxane, Anisole or DMF as a solvent (when using two solvents as a mixed solvent, the volume ratio is 1:1 or 3:1).

[0058] The equation for the O-ATRP polymerization reaction of methacrylate in this embodiment is as follows:

[0059]

[0060] Polymerization process: The prepared polymerization system was degassed, deoxygenated, and dehydrated through a three-stage refrigeration pump-thawing cycle, and then argon gas was reinjected into the quartz reaction tube. The reaction was carried out at room temperature under LED illumination. After the reaction, methanol was added to the reaction solution to precipitate the polymer. The filtrate was removed by suction filtration using a Buchner funnel. The filter cake was washed three times with methanol to remove impurities and purify the polymer. The polymer molecular weight and polydispersity were analyzed by gel permeation chromatography. Specific details are shown in Table 1.

[0061] Table 1. Details of the O-ATRP polymerization system and product results analysis in Example 1.

[0062]

[0063]

[0064] Note: The shortest wavelength of white light in Table 1 is 410nm and the longest wavelength is 780nm, with the short wavelength peak at 450nm and the long wavelength peak at 560nm.

[0065] Example 2

[0066] O-ATRP block polymerization (molar percentage)

[0067] Functional polymer monomers: 87-94.9999%;

[0068] The organohalogen initiator was 5% of the polymer isolated and purified in Example 1;

[0069] Organic photocatalyst 0.0001~8%.

[0070] The light source, illumination time, and solvent amount were the same as those used for the O-ATRP polymerization of the polymer isolated and purified in Example 1, with the polymer isolated and purified in Example 1 used as the organohalogen initiator. The O-ATRP block polymerization results are shown in Table 2.

[0071] The equation for the O-ATRP polymerization reaction of methacrylate in this embodiment is as follows:

[0072]

[0073] Table 2. Details of the O-ATRP polymerization system and product results analysis in Example 2.

[0074]

[0075] Note: The shortest wavelength of white light in Table 2 is 410nm and the longest wavelength is 780nm, with the short wavelength peak at 450nm and the long wavelength peak at 560nm.

[0076] Example 3

[0077] O-ATRP multiblock polymerization (molar percentage):

[0078] The organohalogen initiator was 5% of the polymer isolated and purified in Example 2;

[0079] Monomer content (different from the polymer used) 87~94.9999%;

[0080] Organic photocatalyst 0.0001~8%.

[0081] The light source, illumination time, and solvent amount were the same as those used for the O-ATRP polymerization of the polymer isolated and purified in Example 1, and the polymer isolated and purified in Example 2 was used as the organohalogen initiator. The O-ATRP block polymerization results are shown in Table 3.

[0082] The equation for the O-ATRP polymerization reaction of methacrylate in this embodiment is as follows:

[0083]

[0084] Table 3. Details and product results analysis of the O-ATRP block polymerization system in Example 3.

[0085]

[0086] Note: The shortest wavelength of white light in Table 3 is 410nm and the longest wavelength is 780nm, with the short wavelength peak at 450nm and the long wavelength peak at 560nm.

[0087] As can be seen from the above embodiments, the present invention provides an application of a long alkylamide side-chain triphenylamine compound as an organic photocatalyst, wherein the long alkylamide side-chain triphenylamine compound is one or more compounds with structures shown in Formulas 1 to 15. The present invention provides the application of one or more long alkylamide side-chain triphenylamine compounds with structures shown in Formulas 1 to 15 as organic photocatalysts. First, the long alkylamide side-chain triphenylamine compound provided by this invention can be matched with safe and environmentally friendly white LED light sources. Second, the long alkylamide side-chain triphenylamine compound provided by this invention has both long fluorescence and phosphorescence lifetimes, maintaining high initiation efficiency in both the early stages of low-viscosity polymerization and the later stages of high-viscosity polymerization. Specifically, as the polymerization process progresses, the system viscosity increases with the extension of polymerization time. Taking the provided long alkylamide side-chain triphenylamine compound as an example, the photocatalyst has both long fluorescence and phosphorescence lifetimes. Low viscosity is initiated by excited singlet state (fluorescence), and high viscosity is initiated by excited triplet state (phosphorescence). The polymer obtained after polymerization has a large molecular weight and low dispersion (as shown in Tables 1, 2, and 3). In contrast, benzothiadiazole and phenothiazine with short phosphorescence lifetimes, or eosin Y with both short fluorescence and phosphorescence lifetimes, cannot maintain effective initiation in the later stages of high-viscosity polymerization, resulting in polymerization products that are mainly low molecular weight oligomers, which cannot be separated and purified from the polymerization system (as shown in Tables 4 to 6). Third, the long alkylamide side-chain triphenylamine compound provided by this invention can undergo electron transfer with a halogenated initiator in the excited state, forming a long-lived cationic free radical species that can further absorb photons to form a free radical cationic excited state, thereby exhibiting a rapid chain deactivation rate. This further shortens the polymerization time and improves polymerization controllability. Specifically, the long cationic free radical lifetime manifests macroscopically as more effective chain deactivation, which on the one hand accelerates the polymerization rate, resulting in a larger molecular weight of the polymer within the same time frame; on the other hand, more effective chain deactivation makes the polymerization more controllable, with a polydispersity closer to 1. Polymer controllability is reflected in the polydispersity of the polymer product. It is generally believed that the polydispersity of atom transfer radical polymerization is less than 1.5, and the closer it is to 1, the more controllable the polymerization.

[0088] Comparative Example 1

[0089] The difference from experiments 1-3 in Example 1 is that the organic photocatalyst A1 or A2 was replaced with benzothiadiazole. Details of the resulting polymerization system and product results analysis are shown in Table 4.

[0090] Table 4. Details of the polymerization system and product results obtained from benzothiadiazole.

[0091]

[0092] Comparative Example 2

[0093] The difference from experiments 1-3 in Example 1 is that the organic photocatalyst A1 or A2 was replaced with phenothiazine. Details of the resulting polymerization system and product results analysis are shown in Table 5.

[0094] Table 5. Details of the polymerization system and product results obtained from phenothiazine.

[0095]

[0096] Comparative Example 3

[0097] The difference from experiments 1-3 in Example 1 is that the organic photocatalyst A1 or A2 was replaced with eosin Y. Details of the resulting polymerization system and product results analysis are shown in Table 6.

[0098] Table 6. Details of the polymer system and product results obtained from Eosin Y.

[0099]

[0100] Tables 4-6 show that benzothiadiazole, phenothiazine, or eosin Y, when used as photocatalysts, cannot yield number-average molecular weight and polydispersity. This is because benzothiadiazole and phenothiazine, which have short phosphorescence lifetimes, or eosin Y, which has both short fluorescence and phosphorescence lifetimes, cannot maintain effective initiation in the later stages of high-viscosity polymerization. As a result, the polymerization products are mainly low-molecular-weight oligomers, which cannot be separated and purified from the polymerization system, and therefore, number-average molecular weight and polydispersity data cannot be measured.

[0101] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Use of long alkyl amide side chain triphenylamine compounds as organic photocatalysts in metal-free organic photocatalytic atom transfer radical polymerization, characterized in that, The long alkylamide side-chain triphenylamine compound is one or more compounds with structures shown in Formulas 1 to 15: Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8 Formula 9 Formula 10 Formula 11 Formula 12 Formula 13 Formula 14 Formula 15.

2. A metal-free organophotocatalytic atom transfer radical polymerization system, comprising an organic photocatalyst, an organic halide initiator, and a functional polymerization monomer, characterized in that, The organic photocatalyst is a long alkylamide side-chain triphenylamine compound, and the long alkylamide side-chain triphenylamine compound is one or more compounds with structures shown in Formulas 1 to 15: Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8 Formula 9 Formula 10 Formula 11 Formula 12 Formula 13 Formula 14 Formula 15.

3. The metal-free organophotocatalytic atom transfer radical polymerization system according to claim 2, characterized in that, Based on the total molar percentage of organic photocatalyst, organohalide initiator and functional polymeric monomer as 100%, the molar percentage of organic photocatalyst is 0.0001~8%, the molar percentage of functional polymeric monomer is 82~98.9999%, and the molar percentage of organohalide initiator is 1~10%.

4. The metal-free organophotocatalytic atom transfer radical polymerization system according to claim 2 or 3, characterized in that, The functional polymer monomer is a monomer having vinyl unsaturated groups.

5. The metal-free organophotocatalytic atom transfer radical polymerization system according to claim 4, characterized in that, The functional polymer monomers include one or more of acrylate monomers, styrene monomers, maleimide monomers, and borneol monomers.

6. The metal-free organophotocatalytic atom transfer radical polymerization system according to claim 2 or 3, characterized in that, The organohalogen initiator includes organochlorides and / or organobromines.

7. The metal-free organophotocatalytic atom transfer radical polymerization system according to claim 2, characterized in that, The metal-free organic photocatalytic atom transfer radical polymerization system also includes a solvent.

8. The metal-free organophotocatalytic atom transfer radical polymerization system according to claim 7, characterized in that, The solvent includes one or more of benzene, toluene, anisole, chlorobenzene, dichlorobenzene, tetrahydrofuran, 1,4-dioxane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, sulfolane, acetonitrile, and benzonitrile.

9. A polymerization reaction, characterized in that, Includes the following steps: The polymerization system undergoes a polymerization reaction under the illumination of a light source; The polymerization system is the metal-free organophotocatalytic atom transfer radical polymerization system as described in any one of claims 2 to 8.

10. The polymerization reaction according to claim 9, characterized in that, The light source is a light source with a wavelength of 410 nm, a light source with a wavelength of 450 nm or a white light LED light source; the power of the light source is 5-20 mW / cm 2 ; The polymerization reaction is carried out at a temperature of 20-40°C for 8-18 hours.

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