CN113388058B

CN113388058B - Method for full-spectrum induced controllable free radical polymerization by using organic catalyst

Info

Publication number: CN113388058B
Application number: CN202110638891.3A
Authority: CN
Inventors: 肖龙强; 李秋雨; 卢振; 付晓玲; 刘亚彬; 赵玉来; 蔡静宇; 阴翔宇; 侯琳熙
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2021-06-08
Filing date: 2021-06-08
Publication date: 2022-04-01
Anticipated expiration: 2041-06-08
Also published as: CN113388058A

Abstract

The invention discloses an application of an organic catalyst in full-spectrum induced controllable free radical polymerization. The catalyst is 3, 8-diamino-5-R-6-R' -halogenated phenanthridine salt, wherein R is alkyl with 1-6 carbon atoms; r' is phenyl or p-nitrophenyl. At room temperature, the catalyst is mixed with a polymerization monomer, an initiator and a solvent, and under the protection of inert gas, the mixture is irradiated by an LED lamp belt to carry out reversible complex polymerization reaction, so that a polymer with low dispersity and various block polymers can be obtained, the polymerization conversion rate is high, the activity of the prepared polymer chain end is good, the reaction in a water phase or an oil phase can be realized for different types of monomers, and the range of the selectable monomers is expanded.

Description

Method for full-spectrum induced controllable free radical polymerization by using organic catalyst

Technical Field

The invention belongs to the technical field of polymer material preparation, and particularly relates to an application of an organic catalyst in full-spectrum induced controllable free radical polymerization.

Background

The controllable free radical polymerization can be used for preparing high molecular materials with various topological structures with precise structures, controllable molecular weights and uniform distribution. These high molecular polymers are widely used in the fields of clinical medicine, biomedicine, medical care, cosmetics, pesticide release and the like. Therefore, methods of controlled radical polymerization, such as nitroxide-stabilized radical polymerization (NMP), Atom Transfer Radical Polymerization (ATRP), reversible addition-fragmentation chain transfer radical polymerization (RAFT), reversible chain transfer catalytic polymerization (RTCP), reversible complex-mediated polymerization (RCMP), and the like, are also being continuously developed. These polymerization techniques open up a new way for the diversity of the polymer structure and the function. In recent years, light-induced free radical polymerization is rapidly developed due to the characteristics of low cost, environmental protection, mildness, high efficiency and stronger space-time controllability, and an important mode is provided for realizing wider application of polymers.

As a controllable free radical polymerization method, Photo-induced controllable complex-mediated polymerization (Photo-RCMP) has many advantages, such as diverse catalyst forms, no metal, simple operation, cheap catalyst, energy saving, space-time controllability, low polydispersity, good functional group tolerance, mild conditions, and few side reactions, and is widely studied. Meanwhile, RCMP can be used for synthesizing a polymer with definite composition, controllable molecular weight and uniform molecular weight.

The solar spectrum covers wavelengths of 250-2500 nm, the infrared energy alone accounts for nearly 50% of the solar energy, while the visible and near-infrared photons at sea level account for 95% of the solar flux. Therefore, broadband and near-infrared absorption are essential conditions for achieving efficient use of solar energy. In addition, near infrared has a very low absorption rate and a high penetrating power, can penetrate opaque materials including human tissues, and thus has potential uses in medical diagnosis and treatment, and even in vivo polymerization. And the near infrared light enhances the permeability, thereby realizing the rapid and efficient light control polymerization. The controllable free radical polymerization technology initiated by infrared light (NIR) has wide application prospect in the field of solar-driven 'green' synthesis, and the development of the technology not only has potential biomedical application, but also can provide a new cheaper and more environment-friendly way for industrial polymer synthesis. Therefore, finding a method which can be simultaneously used for full-spectrum induced reversible complexation mediated polymerization of an oil phase and a water phase is very necessary for saving energy and expanding the productivity.

Disclosure of Invention

The invention aims to provide an application of an organic catalyst in full-spectrum induced controllable free radical polymerization, which can realize the polymerization of different monomers in a water phase or an oil phase and is beneficial to expanding the range of usable monomers.

In order to achieve the purpose, the invention adopts the following technical scheme:

an application of an organic catalyst in full-spectrum induced controllable free radical polymerization reaction, wherein the organic catalyst is 3, 8-diamino-5-R-6-R' -halogenated phenanthridine salt, and the molecular structural formula of the organic catalyst is as follows:

，

wherein R is an alkyl group having 1 to 6 carbon atoms; r' is phenyl or p-nitrophenyl; x is Br or I.

The specific method for applying the organic catalyst to full-spectrum induced controllable free radical polymerization reaction is that at room temperature, the organic catalyst is directly or after pretreatment mixed with a polymerization monomer and an initiator in a polymerization tube, and then under the protection of inert gas, an LED lamp belt is used for irradiation to carry out reversible complex polymerization (RCMP), so that low-dispersity (low dispersion degree) (RCMP) can be obtainedM _w/M _n= 1.09-1.37), polymer with controllable molecular weight and uniform distribution and various embedded blocksA block polymer.

Preferably, when X is iodine, the organic catalyst can be used directly; when X is Br, the organic catalyst is required to be pretreated; dissolving potassium iodide in a methanol solution until the potassium iodide is saturated, then adding the organic catalyst, stirring and dispersing for 24 hours, filtering, and repeatedly washing with water for 3 times; the obtained product is stirred and dispersed, filtered and washed in saturated methanol solution of potassium iodide again, and the operation is repeated for 3 times to obtain a finished product; the volume ratio of water to methanol in the methanol solution used was 1: 1.

Preferably, the polymerized monomer is tert-butyl methacrylate (bt-BuMA), benzyl methacrylate (BzMA), Methyl Methacrylate (MMA), Butyl Acrylate (BA), phenyl methacrylate (PhMA), Butyl Methacrylate (BMA), Glycidyl Methacrylate (GMA), Methyl Acrylate (MA), methoxyethyl methacrylate (MEMA), hydroxyethyl methacrylate (HEMA), diethylaminoethyl methacrylate (DEAEMA), dimethylaminoethyl methacrylate (DMAEMA), hydroxypropyl methacrylate (HPMA), Sodium Methacrylate (SMA), polyethylene glycol methacrylate (PEGMA).

Preferably, the initiator is any one of 2-iodo-2-methylpropionitrile (CP-I), alpha-iodophenylacetic acid ethyl ester (PhE-I), alpha-iodophenylacetonitrile (PhCN-I), 2-iodo-2-methyl malonic acid diethyl ester (EEMA-I), iodo-polymethyl methacrylate (PMMA-I), iodo-polyethylene glycol methacrylate (PPEGMA-I).

Preferably, the reaction system of the reversible complex polymerization reaction also comprises a solvent; the solvent is any one of N, N-Dimethylformamide (DMF), Tetrahydrofuran (THF), toluene, anisole, 1, 4-dioxane, dimethyl sulfoxide (DMSO), acetone, water and absolute ethyl alcohol.

Preferably, the molar ratio of the polymerization monomers, solvent, initiator and organic catalyst used is 50:50:5:1 to 8000:0:80: 40.

Preferably, the inert gas is nitrogen or argon.

Preferably, the power of the LED lamp strip is 13W-cm^-1Irradiance of 15 mW cm^-2The irradiation time was 12 hours.

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

(1) the organic catalyst is used for full-spectrum induced controllable free radical polymerization, and low dispersion degree (A) can be obtained in a short timeM _w/M _n= 1.09-1.37) and various block polymers, the obtained polymer chain end activity is good, and the conversion rate of the polymerization system is high.

(2) The method for carrying out full-spectrum induced controllable free radical polymerization reaction by using the organic catalyst, disclosed by the invention, has the advantages that the energy consumption is saved, and the environment is protected by using the light-induced polymerization reaction; meanwhile, the method can be applied under the full spectrum and has good development potential.

(3) The invention firstly provides a method for carrying out full-spectrum induced controllable free radical polymerization reaction by using an organic catalyst, and the monomer can be oil-soluble and water-soluble monomers and has wide applicability.

(4) The invention has strong space-time controllability and can realize the light control switching process.

Drawings

FIG. 1 shows XPS survey spectra (a) and I3 d spectra (b) of the catalyst prepared in example 1.

FIG. 2 shows the polymerization kinetics curves (a) obtained by catalyzing reversible complexation polymerization in oil phase with different catalyst amounts and the molecular weights (A) of the resulting polymerization products in example 2M _n) Degree of dispersion (C)M _w/M _n) Graph (b) relating to conversion.

FIG. 3 is a graph showing the difference DP (n) in the oil phases in examples 3 to 5_Monomer/n_Initiator) The polymerization kinetic curve (a) obtained by the catalytic reversible complexation polymerization and the molecular weight of the obtained polymerization product (A)M _n) Degree of dispersion (C)M _w/M _n) Graph (b) relating to conversion.

FIG. 4 is a Gel Permeation Chromatography (GPC) graph of BzMA (a), PhMA (b), GMA (c), MEMA (d) monomer chain extension polymerization using PMMA-I as a macroinitiator.

FIG. 5 is a plot of the polymerization kinetics obtained by the switching lamp control experiment in the oil phase in example 7.

FIG. 6 shows the polymerization kinetics curves obtained by catalyzing reversible complexation polymerization in the oil phase under different light sources and the molecular weights of the polymerization products obtained in example 8: (a)M _n) Degree of dispersion (C)M _w/M _n) Graph (b) relating to conversion.

FIG. 7 shows the kinetics of polymerization (a) and the molecular weights of the resulting polymers obtained by the reversible complexation polymerization catalyzed by different light sources in the aqueous phase in example 12: (M _n) Degree of dispersion (C)M _w/M _n) Graph (b) relating to conversion.

FIG. 8 shows the kinetics of polymerization (a) and the molecular weights of the resulting polymers obtained in example 13 by red light catalyzed reversible complexation polymerization in aqueous phase under different barriersM _n) Degree of dispersion (C)M _w/M _n) Graph (b) relating to conversion.

FIG. 9 is a graph showing the polymerization kinetics obtained by the catalytic reversible complexation polymerization in example 18 with different light sources in the aqueous phase on and off.

FIG. 10 is a Gel Permeation Chromatography (GPC) graph of chain extension polymerization of PEGMA monomer using PPEGMA-I as a macroinitiator in example 19.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

The following polymerization reactions are all exemplified by the initiator (CP-I), but other iodine-containing initiators are also suitable.

Example 1:

iodinationPreparing ethidine: 10 mL of methanol solution (V) was prepared_{Water (W)}:V_Methanol=1: 1); dissolving potassium iodide (KI) in the solvent until saturation is reached; 1 g of ethidium bromide was dispersed in the above saturated solution, stirred for 24 hours, filtered, and washed 3 times with 20 mL of distilled water. And stirring and dispersing the obtained product in a saturated methanol solution of potassium iodide again, filtering and washing, and repeating the operation for 3 times to obtain a finished product.

FIG. 1 shows XPS pattern (a) and I3 d spectrum (b) of ethidium iodide prepared in this example. It can be seen from the figure that the iodide ion has replaced the bromide ion.

Example 2:

0, 5, 10, 20 and 40 mg of the product from example 1 were taken, respectively, and the mixture was introduced together with MMA (2 mL, 18.6 mmol) and CP-I (21. mu.L, 0.186 mmol) into a 25 mL Schlenk tube under nitrogen atmosphere using a white LED lamp strip (13W. m)^-1、15 mW·cm^-2) The irradiation was carried out for 12 hours. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 2.

FIG. 2 shows the kinetic curves of the polymerization (a) and the molecular weights of the polymerization products (A), (B) and (C) obtained by the reversible complexation polymerization with different amounts of catalystM _n) Graph (b) relating degree of dispersion (PDI) to conversion. As can be seen, under the polymerization conditions, a polymer with controllable molecular weight and uniform distribution can be obtained.

Example 3:

20 mg of the product from example 1, MMA (4 mL, 37.2 mmol) and CP-I (21. mu.L, 0.186 mmol) were taken in a 25 mL Schlenk tube and under nitrogen atmosphere using a white LED lamp strip (13W. m)^-1、15 mW·cm^-2) The irradiation was carried out for 12 hours. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 3.

Example 4:

20 mg of the product from example 1 are takenMMA (8 mL, 74.4 mmol), CP-I (21. mu.L, 0.186 mmol) were placed in a 25 mL Schlenk tube under nitrogen with a white LED strip (13W. m)^-1、15 mW·cm^-2) The irradiation was carried out for 12 hours. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 3.

Example 5:

2 mg of the product from example 1, MMA (2 mL, 18.6 mmol) and CP-I (2.1. mu.L, 0.0186 mmol) were taken, and the mixture was introduced into a 25 mL Schlenk tube and protected with nitrogen using a white LED lamp strip (13W. m)^-1、15 mW·cm^-2) The irradiation was carried out for 12 hours. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 3.

As can be seen from FIG. 3, at various DPs (n)_Monomer/n_Initiator) The polymer with controllable molecular weight and uniform distribution can be obtained, and the theoretical molecular weight is closer to the actual molecular weight. Higher DP leads to higher molecular weight polymers, demonstrating that ethidium bromide can catalyze the formation of ultra high molecular weight polymers.

Example 6:

20 mg of the product from example 1, MMA (2 mL, 18.6 mmol) and CP-I (21. mu.L, 0.186 mmol) were taken in a 25 mL Schlenk tube and under nitrogen atmosphere using a white LED lamp strip (13W. m)^-1，15 mW·cm^-2) After 9h of irradiation, a trace of the mixture was taken to determine a monomer conversion of 31.33%. Then the obtained product is swelled in a small amount of THF (1 mL), the catalyst is removed through a filter head, then 8 mL of ether is used for precipitation, centrifugation is carried out, THF swelling-ether precipitation-centrifugation circulation is carried out for 2 times, and the obtained precipitate is dried in vacuum to obtain the macroinitiator PMMA-I. Measuring the molecular weight by Gel Permeation Chromatography (GPC)M _n=3500, dispersity PDI = 1.15.

10 mg of the product of example 1, PMMA-I (100 mg, 0.0286 mmol) were taken and separately reacted withBzMA (0.97 mL, 5.71 mmol), PhMA (0.88 mL, 5.71 mmol), GMA (0.76 mL, 5.71 mmol), and MEMA (0.87 mL, 5.71 mmol) were added together to a 25 mL Schlenk tube, and under inert gas, a white LED strip (13W. m.) was used^-1，15 mW·cm^-2) After 18 hours of irradiation, the trace amount of the mixture was diluted with tetrahydrofuran, and the catalyst was removed through a filter head, followed by measurement by Gel Permeation Chromatography (GPC), and the results are shown in FIG. 4.

FIG. 4 is a GPC chart of BzMA, PhMA, GMA, and MEMA monomer chain extension polymerization using PMMA-I as a macroinitiator. As can be seen from the figure, the GPC curve after polymerization is significantly shifted to the left, the molecular weight becomes large, indicating that PMMA-I initiates polymerization and that the polymer chain ends have good chain end fidelity.

Example 7:

20 mg of the product from example 1, MMA (2 mL, 18.6 mmol) and CP-I (21. mu.L, 0.186 mmol) were introduced into a 25 mL Schlenk tube and, under nitrogen, a white LED lamp strip (13W. m)^-1，15 mW·cm^-2) After 2 hours of irradiation and 2 hours of lamp turning off, the irradiation was repeated 4 times, and a trace amount of the mixture was taken every two hours, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 5.

FIG. 5 is a plot of the polymerization kinetics of the time-controlled experiment. As can be seen from the figure, the polymerization reaction hardly proceeds in the dark, which illustrates the strict control of the polymerization light reception, and has good space-time (i.e., on-off controllability of the light source).

Example 8:

20 mg of the product from example 1, MMA (2 mL, 18.6 mmol) and CP-I (21. mu.L, 0.186 mmol) were taken and introduced into a 25 mL Schlenk tube under nitrogen with green, white, red and blue LED strips (13 W.m.^-1，15 mW·cm^-2) The irradiation was carried out for 12 hours. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 6.

As can be seen from FIG. 6, the different light sources of different colors have different slopes of the polymerization kinetics curve, i.e.different polymerization rates, mainly due to the different absorption of the light sources of different wavelengths by the catalyst. From the figure it can be seen that the polymerization rate: white > blue > green > red.

Example 9:

10 mg of the product of example 1, CP-I (11. mu.L, 0.094 mmol) were taken, and each was put into a 25 mL Schlenk tube together with BMA (3.013 mL), BzMA (3.195 mL), GMA (2.498 mL), PhMA (2.907 mL) and MEMA (1.410 mL), and under nitrogen atmosphere, a white LED strip (13W. m.) was used^-1，15 mW·cm^-2) The irradiation was carried out for 12 hours. Taking a trace amount of mixture at regular intervals, diluting with tetrahydrofuran, removing catalyst through a filter head, and measuring parameters such as conversion rate, molecular weight and dispersity by using a Gel Permeation Chromatograph (GPC); the monomer conversion was calculated by measuring nuclear magnetism, and the results are shown in Table 1 (Nos. 1 to 5).

Example 10:

20 mg of the product of example 1, MMA (2 mL, 18.6 mmol) and CP-I (21. mu.L, 0.186 mmol) were taken out and put in a 25 mL Schlenk tube, and after irradiating with sunlight for 12 hours under nitrogen protection, a trace amount of the mixture was taken out, diluted with tetrahydrofuran and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight and dispersibility were measured by Gel Permeation Chromatography (GPC), and the results are shown in Table 1 (No. 6).

Example 11:

20 mg of the product of example 1, MMA (2 mL, 18.6 mmol), CP-I (21. mu.L, 0.186 mmol) and dimethyl sulfoxide (2 mL) were taken and put in a 25 mL Schlenk tube, and the mixture was irradiated with white light under nitrogen atmosphere for 12 hours, and then a trace amount of the mixture was taken, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight and dispersibility were measured by Gel Permeation Chromatography (GPC), and the results were shown in Table 1 (No. 7).

TABLE 1

As can be seen from Table 1, the bulk polymerization of different monomers can be realized in the sun, and various monomers have higher conversion rate and low polymerization dispersity, so that the polymerization system has wide monomer universality and great application prospect.

Example 12:

10 mg of the product of example 1, PEGMA (1.5 mL, 3.4 mmol), CP-I (13. mu.L, 0.11 mmol), and 1.5 mL of H were taken₂O or Ethanol, into a 25 mL Schlenk tube, and under nitrogen protection, using red, green, blue, and white LED strips (13W · m), respectively^-1，15 mW·cm^-2) The irradiation was carried out for 12 hours. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 7.

As can be seen from FIG. 7, the different light sources of different colors have different slopes of the polymerization kinetics curve, i.e.different polymerization rates, mainly due to the different absorption of the light sources of different wavelengths by the catalyst. From the figure it can be seen that the polymerization rate: white > blue > red > green.

Example 13:

10 mg of the product of example 1, PEGMA (1.5 mL, 3.4 mmol), CP-I (13. mu.L, 0.11 mmol), and 1.5 mL of H were taken₂O or Ethanol, into a 25 mL Schlenk tube, under nitrogen, using a red LED strip (13 W.m)^-1，15 mW·cm^-2) The red light penetration was demonstrated with pigskin or a4 paper as a barrier after 12 hours of irradiation. The trace amount of the mixture was taken at regular intervals, diluted with tetrahydrofuran, and the catalyst was removed through a filter head, and then parameters such as conversion, molecular weight, and dispersion were measured by Gel Permeation Chromatography (GPC), and the results are shown in fig. 8.

As can be seen from fig. 8, the polymerization rate decreased significantly with the decrease in light transmission (without barrier > pigskin > a4 paper), and the polymerization conversion rate was low and the molecular weight was small at the same reaction time. But the polymerization overall rate is faster under the action of the barrier, which proves that the polymer has the potential of polymerization in vivo and has good development prospect.

Example 14:

10 mg of the product from example 1, CP-I (13. mu.L, 0.11 mmol), DMAEMA (385. mu.L, 2.2 mmol) and 385. mu.L of H were taken₂O, into a 25 mL Schlenk tube under nitrogen with a red LED strip (13 W.m)^-1，15 mW·cm^-2) Irradiating for 5 hr, diluting with tetrahydrofuran, filtering to remove catalyst, and measuring parameters such as conversion rate, molecular weight and dispersity with Gel Permeation Chromatograph (GPC); the monomer conversion was calculated by measuring nuclear magnetism, and the results are shown in Table 2 (number 1).

Example 15:

10 mg of the product from example 1, CP-I (13. mu.L, 0.11 mmol), DEAEMA (460. mu.L, 2.2 mmol) and 460. mu.L of H were taken₂O, into a 25 mL Schlenk tube under nitrogen with a red LED strip (13 W.m)^-1，15 mW·cm^-2) Irradiating for 12 hr, diluting with tetrahydrofuran, filtering to remove catalyst, and measuring parameters such as conversion rate, molecular weight and dispersity with Gel Permeation Chromatograph (GPC); the monomer conversion was calculated by measuring nuclear magnetism, and the results are shown in Table 2 (number 2).

Example 16:

10 mg of the product from example 1, CP-I (13. mu.L, 0.11 mmol), HPMA (310. mu.L, 2.2 mmol) and 310. mu.L of H were taken₂O, into a 25 mL Schlenk tube under nitrogen with a red LED strip (13 W.m)^-1，15 mW·cm^-2) Irradiating for 12 hr, diluting with tetrahydrofuran, filtering to remove catalyst, and measuring parameters such as conversion rate, molecular weight and dispersity with Gel Permeation Chromatograph (GPC); the monomer conversion was calculated by measuring nuclear magnetism, and the results are shown in Table 2 (No. 3).

Example 17:

10 mg of the product of example 1, PEGMA (1.5 mL, 3.4 mmol), CP-I (13. mu.L, 0.11 mmol), and 1.5 mL of H were taken₂Adding O or Ethanol into a 25 mL Schlenk tube, irradiating for 12 h under the sun under the protection of nitrogen, taking a trace amount of mixture, diluting with tetrahydrofuran, removing the catalyst through a filter head,the results of measurement of the parameters such as conversion, molecular weight and degree of dispersion by Gel Permeation Chromatography (GPC) are shown in Table 2 (No. 4).

TABLE 2

As can be seen from Table 2, each monomer has a relatively high conversion rate and a low degree of polymerization dispersion, and the polymerization system has wide monomer universality and a great application prospect. Meanwhile, the chain extension polymerization of the PEGMA monomer is carried out by using the PPEGMA-I as a macromolecular initiator, the molecular weight is increased after the polymerization, the polymerization conversion rate is higher, and the PPEGMA-I initiates the polymerization, and the chain end of the polymer has good chain end fidelity.

Example 18:

10 mg of the product of example 1, PEGMA (1.5 mL, 3.4 mmol), CP-I (13. mu.L, 0.11 mmol), and 1.5 mL of H were taken₂O was put into a 25 mL Schlenk tube and under nitrogen atmosphere, respectively, with green, red, blue, and white LED strips (13 W.m)^-1，15 mW·cm^-2) Irradiating for 0.5 h, turning off lamp for 0.5 h, repeating the irradiation for 4 times, taking micro-mixture every half hour, diluting with tetrahydrofuran, removing catalyst via filter head, and measuring conversion rate, molecular weight and dispersity with Gel Permeation Chromatograph (GPC).

FIG. 9 is a plot of the polymerization kinetics of the time-controlled experiment. As can be seen from the figure, the polymerization reaction hardly proceeded in the dark, indicating that the polymerization was strictly controlled by light, and had good space-time controllability.

Example 19:

10 mg of the product of example 1, PEGMA (0.5 mL, 1.1 mmol), CP-I (13. mu.L, 0.11 mmol), and 0.5 mL of H were taken₂O or Ethanol is added into a 25 mL Schlenk tube, under the protection of nitrogen, a trace mixture is taken after the Schlenk tube is irradiated for 3 hours under white light, after the trace mixture is diluted by tetrahydrofuran and the catalyst is removed through a filter head, parameters such as conversion rate, molecular weight, dispersity and the like are measured by a Gel Permeation Chromatograph (GPC), and the molecular weight of PPEGMA-I is measured to be 5100, and the polymerization dispersity is 1.15.

PEGMA (1.45 mL, 3.3 mmol) and 1.45 mL of water were added directly to the polymerization solution, and under the protection of inert gas, a white LED lamp strip (13 W.m) was used^-1，15 mW·cm^-2) After 6 hours of irradiation, the mixture was diluted with tetrahydrofuran to remove the catalyst through a filter head, and then measured by Gel Permeation Chromatography (GPC).

FIG. 10 is a GPC chart of chain extension polymerization of PEGMA monomers using PPEGMA-I as a macroinitiator. As can be seen in the figure, the GPC curve after polymerization is significantly shifted to the left, the molecular weight is large, indicating that PPEGMA-I initiates polymerization and that the polymer chain ends have good chain end fidelity.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

Claims

1. The application of an organic catalyst in full-spectrum induced controllable free radical polymerization reaction is characterized in that: the organic catalyst is 3, 8-diamino-5-R-6-R' -halogenated phenanthridine salt, and the molecular structural formula of the organic catalyst is as follows:

，

wherein R is an alkyl group having 1 to 6 carbon atoms; r' is phenyl or p-nitrophenyl; x is Br or I;

the application method comprises the steps of mixing the organic catalyst with a polymerization monomer and an initiator directly or after pretreatment at room temperature, and performing reversible complex polymerization reaction by irradiating an LED lamp belt under the protection of inert gas, thereby obtaining polymers with controllable molecular weight and uniform distribution and various block polymers.

2. Use according to claim 1, characterized in that: the method for pretreating the organic catalyst comprises the steps of dissolving potassium iodide in a methanol solution until the potassium iodide is saturated, then adding the organic catalyst, stirring and dispersing for 24 hours, filtering, and repeatedly washing with water for 3 times; the obtained product is stirred and dispersed, filtered and washed in saturated methanol solution of potassium iodide again, and the operation is repeated for 3 times to obtain a finished product;

the volume ratio of water to methanol in the methanol solution used was 1: 1.

3. Use according to claim 1, characterized in that: the polymerized monomer is one or more of tert-butyl methacrylate, benzyl methacrylate, methyl methacrylate, butyl acrylate, phenyl methacrylate, butyl methacrylate, glycidyl methacrylate, methyl acrylate, methoxyethyl methacrylate, hydroxyethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, hydroxypropyl methacrylate, sodium methacrylate and polyethylene glycol methacrylate.

4. Use according to claim 1, characterized in that: the initiator is any one of 2-iodine-2-methyl propionitrile, alpha-iodophenylacetic acid ethyl ester, alpha-iodophenylacetonitrile, 2-iodine-2-methyl diethyl malonate, iodine-based polymethyl methacrylate and iodine-based polyethylene glycol methacrylate.

5. The use according to claim 1, wherein the reaction system of the reversible complex polymerization reaction further comprises a solvent;

the solvent is any one of N, N-dimethylformamide, tetrahydrofuran, toluene, anisole, 1, 4-dioxane, dimethyl sulfoxide, acetone, water and absolute ethyl alcohol.

6. Use according to claim 1, characterized in that: the inert gas is nitrogen or argon.

7. Use according to claim 1, characterized in that: the power of the LED lamp strip is 13W-cm^-1Irradiance of 15 mW cm^-2。