A method for preparing polycaprolactone through ring-opening polymerization

Abstract

The invention discloses a method for preparing polycaprolactone by ring-opening polymerization, and aims to provide a method for preparing polycaprolactone by ring-opening polymerization with the advantages of high catalytic activity, mild conditions, simple process and the like. The method uses ε-caprolactone as a monomer and trifluoromethanesulfonate metal as a catalyst, and prepares polycaprolactone by a bulk polymerization method under the condition that the reaction temperature is 100-160 DEG C. The invention uses trifluoromethanesulfonate metal as a catalyst for the polymerization preparation of ε-caprolactone, and belongs to the technical field of polymer organic synthesis.

Description

Technical Field

[0001] The present invention relates to a method for preparing polycaprolactone, and in particular to a method for preparing polycaprolactone by bulk polymerization of ε-caprolactone catalyzed by trifluoromethanesulfonic acid metal. Background Art

[0002] Polycaprolactone (PCL) is one of the earliest polymers synthesized by Carothers in 1950 and was commercialized because it can be degraded by microorganisms.

[0003] As research continues, the demand for polycaprolactone will continue to increase. At the same time, factors such as national economic development, national policies and the rise of environmental protection industries will affect the development of polycaprolactone. At present, the output of polycaprolactone is relatively large abroad, and the main production companies are Perstorp, BASF, Daicel, Dow Chemical and other European, American or Japanese companies. Domestic production is relatively small, mainly imported from foreign companies, so it is very important to accelerate the localization of polycaprolactone, and the domestic market prospects are very broad.

[0004] Chinese patent CN202210972931.2 discloses a method for preparing β-cyclodextrin / polycaprolactone-polylactic acid polycaprolactone copolymer inclusion compound microspheres, comprising the following steps:

[0005] (1) dissolving polycaprolactone, lactide and caprolactone in toluene, using polycaprolactone as a macromolecular initiator, and carrying out ring-opening polymerization under a nitrogen atmosphere under the catalysis of stannous octoate, and then obtaining a polycaprolactone-polylactic acid polycaprolactone copolymer by ether precipitation, centrifugation and washing;

[0006] (2) dissolving the polycaprolactone-polylactic acid-polycaprolactone copolymer in an acetone solution and heating the solution to a target temperature to obtain an acetone solution of the polycaprolactone-polylactic acid-polycaprolactone copolymer;

[0007] (3) adding the aqueous solution of β-cyclodextrin dropwise to the acetone solution of polycaprolactone-polylactic acid-polycaprolactone copolymer and stirring vigorously to obtain a mixed solution;

[0008] (4) continuing to stir the mixed solution at room temperature for a predetermined time, and then centrifugally washing with acetone and water to obtain a β-cyclodextrin / polycaprolactone-polylactic acid-polycaprolactone copolymer inclusion complex;

[0009] (5) Ultrasonic dispersion of β-cyclodextrin / polycaprolactone-polylactic acid-polycaprolactone copolymer inclusion complex in a solvent to obtain inclusion complex microspheres.

[0010] CN202211102478.6 A polycaprolactone derivative and a preparation method thereof discloses a preparation method of a polycaprolactone derivative, which comprises the steps of:

[0011] Under the protection of an inert atmosphere, a caprolactone derivative, an alcohol initiator, an organic acid catalyst, and a solvent are added into a reactor, and stirred to react at room temperature to 160° C. to obtain a polycaprolactone derivative;

[0012] Alternatively, under the protection of an inert atmosphere, a caprolactone derivative, an alcohol initiator, and an organic acid catalyst are added to a reactor, and the mixture is stirred and reacted at room temperature to 160° C. to obtain a polycaprolactone derivative;

[0013] The structural formula of the caprolactone derivative is as follows: the R' includes one of an alkyl group, an aryl group, a functional side group, an oligoethylene glycol side chain, a fluorinated alkyl side chain, and a silicon-containing side chain.

[0014] The current processes for catalytic ring-opening polymerization of caprolactone all have shortcomings, and it is of great significance to develop a method for preparing polycaprolactone under mild conditions, with high efficiency and high product performance. Summary of the invention

[0015] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing polycaprolactone by ring-opening polymerization with high catalytic activity, mild conditions and simple process.

[0016] To achieve the above object, the technical solution adopted by the present invention is:

[0017] A method for preparing polycaprolactone by ring-opening polymerization, using ε-caprolactone as a monomer and trifluoromethanesulfonic acid metal as a catalyst, reacting at a temperature of 100 to 160° C. under normal pressure for 4 to 16 hours, after which the reaction product precipitates for 1 hour, collecting the precipitate, washing and vacuum drying to obtain polycaprolactone;

[0018] Wherein: the molar ratio of monomer to catalyst is 200-2000:1.

[0019] Furthermore, in the above-mentioned method for preparing polycaprolactone by ring-opening polymerization, the trifluoromethanesulfonate metal salt is one or more of zinc trifluoromethanesulfonate, scandium trifluoromethanesulfonate, indium trifluoromethanesulfonate, aluminum trifluoromethanesulfonate, cerium trifluoromethanesulfonate, and copper trifluoromethanesulfonate.

[0020] Furthermore, in the above-mentioned method for preparing polycaprolactone by ring-opening polymerization, the reaction temperature is 120-160°C.

[0021] Furthermore, in the above method for preparing polycaprolactone by ring-opening polymerization, the molar ratio of the monomer to the catalyst is 500-1500:1.

[0022] Furthermore, in the above-mentioned method for preparing polycaprolactone by ring-opening polymerization, the reaction time is 6 to 12 hours.

[0023] Furthermore, in the above method for preparing polycaprolactone by ring-opening polymerization, tetrahydrofuran is used for washing.

[0024] Furthermore, in the above-mentioned method for preparing polycaprolactone by ring-opening polymerization, the vacuum degree of vacuum drying is -0.085 MPa, the drying temperature is 40° C., and the drying time is 4 hours.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention adopts bulk polymerization, the product and the catalyst are easy to separate, the operation is convenient, safe and efficient, and the process is simple;

[0027] 2. The reaction conditions of the present invention are mild and carried out under normal pressure, avoiding operations such as inert gas protection;

[0028] 3. The monomer conversion rate of the present invention is high and the performance of the polymer is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the gel liquid chromatogram of Example 1;

[0030] Figure 2 is the gel liquid chromatogram of Example 2;

[0031] Figure 3 is the gel liquid chromatogram of Example 3;

[0032] Figure 4 is the gel liquid chromatogram of Example 4;

[0033] Figure 5 is the gel liquid chromatogram of Example 5;

[0034] Figure 6 is the gel liquid chromatogram of Example 6;

[0035] Figure 7 is the gel liquid chromatogram of Example 7;

[0036] Figure 8 is the gel liquid chromatogram of Example 8;

[0037] Fig. 9 is the gel liquid chromatogram of Example 9;

[0038] Fig.10 This is the gel liquid chromatogram of Example 10. DETAILED DESCRIPTION

[0039] The present invention is illustrated by the following examples, but the protection scope of the present invention is not limited to the scope of the following examples.

[0040] Example 1

[0041] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst Zn(CF) are added to a reaction kettle. 3 SO 3 ) 2 , under normal pressure, the reaction temperature is 140°C, the reaction is carried out for 12 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0042] Example 2

[0043] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst Sc(CF) are added to a reaction kettle. 3 SO 3 ) 2 , under normal pressure, the reaction temperature is 140°C, the reaction is carried out for 12 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0044] Example 3

[0045] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst (CF 3 SO 3 ) 3 In, under normal pressure conditions, the reaction temperature was 140°C. After the reaction for 12 hours, the reaction product was precipitated for 1 hour, the precipitate was collected, washed with tetrahydrofuran, and then dried at -0.085 MPa, 40°C for 4 hours to obtain polycaprolactone.

[0046] Example 4

[0047] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst (CF 3 SO 3 ) 3 Al, under normal pressure, the reaction temperature is 140°C, the reaction is carried out for 12 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085 MPa, 40°C for 4 hours to obtain polycaprolactone.

[0048] Example 5

[0049] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst (CF 3 SO 3 ) 3 Ce, under normal pressure conditions, the reaction temperature was 140°C, the reaction was carried out for 12 hours, the reaction product was precipitated for 1 hour, the precipitate was collected, the precipitate was washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0050] Example 6

[0051] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst C are added to a reaction kettle. 2 CuF 6 O 6 S 2 , under normal pressure, the reaction temperature is 140°C, the reaction is carried out for 12 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0052] Example 7

[0053] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst Zn(CF) are added to a reaction kettle. 3 SO 3 ) 2 , under normal pressure, the reaction temperature is 160°C, the reaction is carried out for 4 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0054] Example 8

[0055] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 50 g of ε-caprolactone monomer and 0.1 g of catalyst Zn(CF) are added to a reaction kettle. 3 SO 3 ) 2 , under normal pressure, the reaction temperature is 120°C, the reaction is carried out for 16 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0056] Example 9

[0057] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 20 g of ε-caprolactone monomer and 0.1 g of catalyst Zn(CF3 SO 3 ) 2 , under normal pressure, the reaction temperature is 140°C, the reaction is carried out for 12 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0058] Example 10

[0059] The present application provides a method for preparing polycaprolactone by ring-opening polymerization, wherein 200 g of ε-caprolactone monomer and 0.1 g of catalyst Zn(CF 3 SO 3 ) 2 , under normal pressure, the reaction temperature is 100°C, the reaction is carried out for 16 hours, the reaction product is precipitated for 1 hour, the precipitate is collected, the precipitate is washed with tetrahydrofuran, and then dried at -0.085MPa, 40°C for 4 hours to obtain polycaprolactone.

[0060] The weight average molecular weight (Mw) and dispersion degree (PDI) of the products provided in Examples 1 to 10 are measured by gel permeation chromatography (GPC). The chromatograms are shown in Figures 1 to 10 , the specific data are shown in Table 1.

[0061]

[0062] It can be seen from the above data that the technical solution provided by the present application has a high monomer conversion rate and excellent polymer performance.

Claims

1. A method for preparing polycaprolactone by ring-opening polymerization, characterized in that: Using ε-caprolactone as a monomer and trifluoromethanesulfonic acid metal salt as a catalyst, the reaction is carried out at a temperature of 100-160°C under normal pressure for 4-16 hours, and after the reaction product is precipitated for 1 hour, the precipitate is collected, washed and vacuum dried to obtain polycaprolactone; Wherein: the molar ratio of monomer to catalyst is 200~2000:1; The trifluoromethanesulfonate metal salt is one or more of indium trifluoromethanesulfonate and copper trifluoromethanesulfonate.

2. The method for preparing polycaprolactone by ring-opening polymerization according to claim 1, characterized in that: The reaction temperature is 120~160℃.

3. The method for preparing polycaprolactone by ring-opening polymerization according to claim 1, characterized in that: The molar ratio of the monomer to the catalyst is 500-1500:

1.

4. The method for preparing polycaprolactone by ring-opening polymerization according to claim 1, characterized in that: The reaction time is 6 to 12 hours.

5. The method for preparing polycaprolactone by ring-opening polymerization according to claim 1, characterized in that: The washing solvent is tetrahydrofuran.

6. The method for preparing polycaprolactone by ring-opening polymerization according to claim 1, characterized in that: The vacuum degree of the vacuum drying is -0.085MPa, the drying temperature is 40°C, and the drying time is 4 hours.

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