Method for preparing vinyl ether polymer by photo-initiated polymerization

Abstract

The invention relates to a method for preparing a vinyl ether polymer by photo-initiated polymerization, which comprises the step of: under a protective atmosphere, performing photo-initiated polymerization on a vinyl ether monomer in the presence of an organic halogenated hydrocarbon and manganese carbonyl under irradiation of light having a wavelength of 365-550 nm at −25° C. to 25° C., to obtain a vinyl ether polymer after the reaction is completed. In the method, a vinyl ether monomer is subjected to cationic polymerization in the presence of manganese carbonyl and an organic halogenated hydrocarbon under visible light, to prepare a vinyl ether polymer with controlled molecular weight and narrow molecular weight distribution.

Claims

1. A method for preparing a vinyl ether polymer by photo-initiated polymerization, comprising a step of: under a protective atmosphere, performing photo-initiated polymerization on a vinyl ether monomer of Formula (1) in the presence of an organic halogenated hydrocarbon and manganese carbonyl under irradiation of light having a wavelength of 365-550 nm at −25° C. to 25° C., to obtain a vinyl ether polymer after the reaction is completed, ##STR00005## wherein R is an alkyl or haloalkyl group, in which the alkyl or haloalkyl group has 1-10 carbon atoms; and wherein the organic halogenated hydrocarbon has a structural formula of ##STR00006## in which X is halogen.

2. The method according to claim 1, wherein the alkyl or haloalkyl group has 2-5 carbon atoms.

3. The method according to claim 1, wherein the vinyl ether monomer has a structural formula of ##STR00007## in which X is halogen.

4. The method according to claim 1, wherein the molar ratio of the vinyl ether monomer, the organic halogenated hydrocarbon and manganese carbonyl is 100-500:1:0.01-0.5.

5. The method according to claim 4, wherein the molar ratio of the vinyl ether monomer, the organic halogenated hydrocarbon and manganese carbonyl is 200-500:1:0.05-0.5.

6. The method according to claim 5, wherein the molar ratio of the vinyl ether monomer, the organic halogenated hydrocarbon and manganese carbonyl is 200:1:0.05-0.5 or 200-500:1:0.2.

7. The method according to claim 1, wherein the polymerization time is 5 min to 5 h.

8. The method according to claim 1, wherein the reaction is performed in an organic solvent.

9. The method according to claim 8, wherein the organic solvent is selected from the group consisting of toluene, n-hexane, ethyl acetate, methylene chloride and any combination thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a kinetic curve (A) at a molar ratio of [IBVE].sub.0:[EBP].sub.0:[Mn.sub.2(CO).sub.10].sub.0 of 200:1:0.2, a change curve (B) of the monomer conversion with time, and a curve (C) of elution by GPC of the polymer;

(2) FIG. 2 shows the .sup.13C NMR (2A-2B), .sup.1H NMR (2C-2D) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF) mass spectrum (2E-2F) of the resulting polymer when IBVE is used as the monomer;

(3) FIG. 3 shows a curve of elution by GPC of each of the polymers obtained with various halogenated hydrocarbons;

(4) FIG. 4 shows a curve of elution by GPC of each of the polymers obtained in various solvents; and

(5) FIG. 5 shows a curve of elution by GPC of each of the polymers obtained with various monomers;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The invention will be further illustrated in more detail with reference to the accompanying drawings and embodiments. It is noted that, the following embodiments only are intended for purposes of illustration, but are not intended to limit the scope of the present invention.

(7) In the following examples of the present invention, the .sup.1H NMR spectrum is obtained by Bruker 300 MHz Nuclear Magnetic Resonance Spectrometer by dissolving the test sample in CDCl.sub.3 as a solvent having tetramethylsilicane (TMS) as an internal standard and then testing. The molecular weight and the polydispersity index of the polymer are determined by Agilent PL-50 gel permeation chromatograph (GPC) using a refractive index detector and a PL mixed gel column D (5 μm bead size), where the molecular weight of the packing in the column ranges from 200 to 4×10.sup.5 g/mol, THF is used as a mobile phase, the flow rate is 1.0 mL min-1, and the sample is injected by a PL-AS RT autosampler. The measurements are made at 40° C., and the molecular weight is calculated with polymethyl methacrylate as a standard.

Examples 1-4

(8) Four 5 mL ampoules were taken, and the vinyl ether monomer IBVE, and the initiator halogenated hydrocarbon and manganese carbonyl were added. One kind of halogenated hydrocarbon was added to each ampoule. The molar ratio of [IBVE].sub.0:[halogenated hydrocarbon].sub.0:[manganese carbonyl].sub.0 was 200:1:0.2, and the volume of the monomer IBVE was 0.5 mL. After 3 cycles of liquid nitrogen freezing-evacuation-nitrogen filling, the ampoule was sealed under vacuum. The ampoule was allowed for reaction under irradiation of a blue LED lamp at a predetermined temperature (0° C.). After a predetermined period of time, the ampoule was opened, a small amount of tetrahydrofuran was added to dissolve the product and the resulting solution was added dropwise to a large amount of methanol for precipitation. After the precipitation was completed, the supernatant was poured off, and the polymer was dried in a vacuum oven after suction filtration. Table 1 shows the results of polymerization in the presence of various halogenated hydrocarbons under the above conditions for various periods of time. In Table 1, M.sub.n,th is calculated by a formula below:[M].sub.0/[halogenated hydrocarbon].sub.0×conversion rate×M+M.sub.EBP)

(9) TABLE-US-00001 TABLE 1 Results of polymerization in the presence of various halogenated hydrocarbons for various periods of time Conver- Exam- sion M.sub.n, th M.sub.n, GPC ple Initiator Time rate (%) (g/mol) (g/mol) 1 BB 36 h 10.7 2300 10500 3.80 2 EBPA 16 h 26.2 5400 24800 2.53 3 EBIB 20 min 69.0 14000 34000 1.96 4 EBP 18 min 93.9 19000 20600 1.29

Examples 5-14

(10) Multiple groups of parallel experiments were performed and the vinyl ether polymers were prepared according to the method in Examples 1-4, except that the monomer was exclusively IBVE, the initiator was exclusively EBP and manganese carbonyl, and the polymerization was carried out at various molar ratios for various periods of time. The results of polymerization are shown in Table 2. In Table 2, the molar ratio refers to [IBVE].sub.0/[EBP].sub.0/[Mn.sub.2(CO).sub.10].sub.0.

(11) TABLE-US-00002 TABLE 2 Results of polymerization at various molar ratios for various periods of time Conver- Exam- Molar sion M.sub.n, th M.sub.n, GPC ple ratio Time rate (%) (g/mol) (g/mol) 5 200:1:0.5 6 min 73.5 14700 16700 1.47 200:1:0.2 14 min 71.6 14500 15900 1.18 7 200:1:0.1 15 min 71.3 14300 18100 1.15 8  200:1:0.05 75 min 81.4 16500 36100 1.34 9  200:1:0.01 38 h 34.6 7100 37800 1.89 10 100:1:0.2 5 min 81.8 8200 11600 1.41 11 500:1:0.2 50 min 58.7 29400 32400 1.46 12 200:1:0.2 5 min 90.3 18300 17800 1.22 13 200:1:0.2 5 h 58.3 11900 20500 1.78

(12) In Table 2, the reaction temperature in Examples 5-11 is 0° C.; the reaction temperature in Example 12 is 25° C., and the reaction temperature in Example 13 is −25° C.

(13) FIG. 1 shows a kinetic curve (A) at a molar ratio of [IBVE].sub.0:[EBP].sub.0:[Mn.sub.2(CO).sub.10].sub.0 of 200:1:0.2, a change curve (B) of the conversion rate of the monomer with time, and a curve (C) of elution by GPC of the polymer, where in figure C, from right to left, the reaction time corresponding to the curve increases one by one.

(14) FIG. 2 shows the .sup.3C NMR (2A-2B), .sup.1H NMR (2C-2D) and MALDI-ToF mass spectrum (2E-2F) of the resulting polymer when IBVE is used as the monomer, where FIG. 2B is a partially enlarged view of 2A; FIG. 2D is a partially enlarged view of 2C; and FIG. 2F is an enlarged view of box a in 2E.

Examples 14-18

(15) Multiple groups of parallel experiments were performed and the vinyl ether polymers were prepared according to the method in Examples 1-4, except that the monomer was exclusively IBVE, the initiator was exclusively EBP and manganese carbonyl, the molar ratio of [IBVE].sub.0:[EBP].sub.0:[manganese carbonyl].sub.0 was 200:1:0.2, an organic solvent was present in the reaction system, and the polymerization was carried out in various solvents for various periods of time. The results of polymerization are shown in Table 3.

(16) TABLE-US-00003 TABLE 3 Results of polymerization in various solvents Conver- Exam- sion M.sub.n, th M.sub.n, GPC ple Solvent Time rate (%) (g/mol) (g/mol) 14 Toluene 40 min 89.9 18200 21100 1.31 15 DCM 20 min 94.6 19100 16400 1.31 16 Hexane 50 min 83.8 17000 23200 1.37 17 EA 3 h 81.2 16400 29600 1.28 18 THF 40 h 18.1 3800 10500 1.14

Examples 19-21

(17) Multiple groups of parallel experiments were performed and the vinyl ether polymers were prepared according to the method in Examples 1-4, except that various monomers were used, the initiator was exclusively EBP and manganese carbonyl, and the molar ratio of [monomer].sub.0:[EBP].sub.0:[manganese carbonyl].sub.0 is 200:1:0.2. The results of polymerization for various periods of time are shown in Table 4.

(18) TABLE-US-00004 TABLE 4 Results of polymerization of various monomers Conver- Exam- sion M.sub.n, th M.sub.n, GPC ple Monomer Time rate (%) (g/mol) (g/mol) 19 EVE 8 min 86.4 12600 16000 1.45 20 BVE 8 min 78.3 18900 26500 1.38 21 Cl-EVE 50 min 67.4 13700 9600 1.22

(19) The above description is only preferred embodiments of the present invention and not intended to limit the present invention, it should be noted that those of ordinary skill in the art can further make various modifications and variations without departing from the technical principles of the present invention, and these modifications and variations also should be considered to be within the scope of protection of the present invention.