A controlled polymerization process for carbon dioxide / propylene oxide / cyclohexene oxide copolymers

Abstract

The application discloses a controllable polymerization method of carbon dioxide / propylene oxide / cyclohexene oxide copolymer, and the chain segment structure can be effectively adjusted through different reaction temperatures by adopting one-pot feeding process. Compared with the prior art, the application adopts one-pot feeding, avoids feeding through a high-pressure pump in the reaction process, reduces equipment investment, and is more simple to operate. Meanwhile, the application can obviously shorten the total reaction time since it is not necessary to wait for the first feeding monomer to be completely reacted.

Description

Technical Field

[0001] This invention belongs to the field of molecular materials, specifically relating to a controlled polymerization method for a carbon dioxide / propylene oxide / cyclohexene oxide copolymer. Background Technology

[0002] With the increasing severity of white pollution caused by traditional plastics, biodegradable plastics are receiving more and more attention. At the same time, as the main greenhouse gas, carbon dioxide is becoming increasingly important due to stricter environmental protection requirements. The synthesis of polymer materials by reacting carbon dioxide with epoxides can both utilize carbon dioxide in a high-value manner and replace non-biodegradable plastics to solve the problem of "white pollution".

[0003] Polypropylene carbonate (PPC) prepared from carbon dioxide and propylene oxide has been industrialized. However, the glass transition temperature of PPC materials is generally only 32-35℃. The dimensional stability of materials prepared alone is poor, and they need to be blended with other crystalline biodegradable materials, which limits their large-scale application. Developing dimensionally stable and temperature-resistant biodegradable carbon dioxide-based plastics has become an urgent problem to be solved.

[0004] Adding epoxy monomers or acid anhydrides with rigid segments during polymerization is an effective method to improve the dimensional stability and temperature resistance of carbon dioxide copolymers. Chinese patent application CN 201010253928.2 discloses a method for preparing temperature-resistant carbon dioxide-based polymers by copolymerizing cyclohexene oxide with carbon dioxide, but the copolymer product is brittle and difficult to process. Chinese patent application CN 201910362655.6 discloses a one-step method for preparing carbon dioxide-based block copolymers using cyclic acid anhydride monomers, lactone monomers, epoxy compounds, and carbon dioxide as monomers, and a mixture of organic Lewis acids and organic Lewis bases as catalysts. This method can improve the glass transition temperature of the polymer while maintaining a certain degree of toughness, but the resulting polymer has a block structure, and due to the addition of acid anhydrides, the carbon dioxide content is low.

[0005] Random copolymers of PO (propylene oxide) / CHO (cyclohexene oxide) / CO2 exhibit good transparency and are used to prepare biaxially oriented films. Their block copolymers demonstrate good toughness and low melt viscosity, making them suitable for injection molding and toughening / compressing modifications of biodegradable plastics. Currently, there is a lack of technical solutions that can switch between block copolymers and random copolymers with minimal changes in steps or parameters. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0008] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a controlled polymerization method for carbon dioxide / propylene oxide / cyclohexene oxide copolymer.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a controlled polymerization method for a carbon dioxide / propylene oxide / cyclohexene oxide copolymer, comprising,

[0010] Propylene oxide, cyclohexene oxide, solvent and catalyst are added to the polymerization reactor. After the autoclave is sealed, carbon dioxide is introduced to maintain the reaction pressure at 3-4 MPa.

[0011] The reaction is carried out at 40℃~100℃ while carbon dioxide is introduced to maintain the reaction pressure at 4~8MPa. The reaction is carried out for 5~20h, and after purification and drying, carbon dioxide / propylene oxide / cyclohexene oxide copolymer is obtained.

[0012] In a preferred embodiment of the method described in this invention, the solvent is selected from one or more of dioxane, dimethyl carbonate, diethyl carbonate, dichloromethane, chloroform, dioxane, and tetrahydrofuran.

[0013] In a preferred embodiment of the method described in this invention, the catalyst accounts for 0.1% to 1% of the total mass of the epoxy monomer.

[0014] In a preferred embodiment of the method described in this invention, the catalyst comprises a porphyrin aluminum catalyst with the following structural formula:

[0015]

[0016] In a preferred embodiment of the method described in this invention, the ratio of propylene oxide to cyclohexene oxide by volume is 0.5–7:0.5–9.5.

[0017] In a preferred embodiment of the method described in this invention, the ratio of the total mass of epoxy monomers to the total mass of solvent is 30:70 to 70:30.

[0018] In a preferred embodiment of the method described in this invention, the heating is performed at a temperature of 40–70°C or 80–100°C.

[0019] In a preferred embodiment of the method described in this invention, when the reaction temperature is 40–70°C, the obtained polymer is a random copolymer, and the prepared terpolymer has only one glass transition temperature.

[0020] In a preferred embodiment of the method described in this invention, when the temperature is 80–100°C, the polymer obtained is a block copolymer.

[0021] As a preferred embodiment of the method described in this invention, the carbon dioxide / propylene oxide / cyclohexene oxide copolymer has a weight-average molecular weight of 200-500 kg / mol and a carbonate unit content of 95%-99.9%.

[0022] Beneficial effects of this invention:

[0023] (1) This invention provides a method for adjusting the chain segment structure of carbon dioxide / propylene oxide / cyclohexene oxide copolymer by reaction temperature. The chain segment structure can be effectively adjusted by using a one-pot feeding process and different reaction temperatures.

[0024] (2) Existing technologies generally use batch feeding to prepare block copolymers. Compared with existing technologies, this invention uses a one-pot feeding method, which avoids feeding through a high-pressure pump during the reaction process, reduces equipment investment, and makes the operation simpler. At the same time, since there is no need to wait for the first batch of monomers to react completely, this invention can significantly shorten the total reaction time. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0026] Figure 1 The DSC spectrum of the carbon dioxide / propylene oxide / cyclohexene oxide copolymer prepared in Example 1 of this invention has only one glass transition temperature, indicating that it is a random copolymer.

[0027] Figure 2 The DSC spectrum of the carbon dioxide / propylene oxide / cyclohexene oxide copolymer prepared in Example 2 of this invention shows two different glass transition temperatures, indicating that it is a block copolymer.

[0028] Figure 3 For the ligand 1 and catalyst of the present invention 1 H-NMR spectrum.

[0029] Figure 4 This is a schematic diagram of the synthesis of the porphyrin aluminum catalyst of the present invention. Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0033] This invention provides a method for preparing a carbon dioxide / propylene oxide / cyclohexene oxide terpolymer using a solution polymerization method. The method involves a one-pot process with controlled reaction temperature to prepare a carbon dioxide / propylene oxide / cyclohexene oxide terpolymer with tunable random / block structures.

[0034] The polymerization process includes: introducing a specified amount of propylene oxide, cyclohexene oxide, and a specific inert solvent into the polymerization reactor in a single step, according to a specified ratio;

[0035] A measured amount of catalyst is added, and a measured amount of carbon dioxide is introduced. The mixture is then heated to the reaction temperature, and the reaction pressure is maintained by adjusting the amount of carbon dioxide added. After a certain reaction time, a carbon dioxide-epoxide copolymer is obtained. The special feature is that the reaction temperature is 50-70℃ or 80-100℃. When the reaction temperature is 50-70℃, the resulting polymer is a random copolymer, and the product has only one glass transition temperature. When the temperature is 80-100℃, the resulting polymer is a block copolymer, and the product has two glass transition temperatures.

[0036] There are no special restrictions on any of the raw materials used in this invention; they can be commercially available.

[0037] All reagents used in the following examples are commercially available.

[0038] The porphyrin aluminum catalyst in this embodiment of the invention has the following structural formula:

[0039]

[0040] The porphyrin aluminum catalyst in this embodiment of the invention is prepared by the following method:

[0041] like Figure 4 As shown, based on the classic Lindsey synthesis method, under nitrogen or argon protection, 5 ml of trifluoroacetic acid was used as a catalyst, 0.5 mol each of p-chlorobenzaldehyde and pyrrole were added, and 200 ml of dichloromethane (DCM) was added as a solvent, and the condensation reaction was carried out at room temperature for 2 h.

[0042] Then, 2g of dichlorocyano-p-benzoquinone (DDQ) was added, and the mixture was reacted at room temperature for 5 hours to undergo oxidative dehydrogenation, yielding p-chlorotetraphenylporphyrin ligand 1. (See [link]). Figure 3 a;

[0043] After adding 1.2 mol of diethylaluminum chloride to 1 mol of ligand 1, the reaction was carried out at room temperature for 5 hours. The product was purified by column chromatography to obtain catalyst 2, which is the porphyrin aluminum catalyst in the examples. See [link to example]. Figure 3 b.

[0044] Example 1

[0045] In a glove box, add 11.6 mg of catalyst, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 3 mL of PO (propylene oxide), 7 mL of CHO (cyclohexene oxide), and 5 mL of DCM (dichloromethane) to a 50 mL autoclave. After sealing the autoclave, remove it and pressurize it to 3 MPa with CO2.

[0046] Place the vessel in a 60℃ water bath. Once the temperature stabilizes, pressurize it to 4MPa with CO2 and start the reaction timing. During the reaction, control the pressure drop to within 0.2MPa. If the pressure is insufficient, promptly pressurize it to 4MPa.

[0047] After reacting for 12 hours, the reactor was placed in an ice-water mixture to terminate the reaction. Once the reactor temperature was below 20°C, the pressure was slowly released to atmospheric pressure, and samples of the crude product were taken for further analysis. 1 H-NMR analysis was used to determine the conversion rate of epoxy monomers and the content of carbonate units. The crude product was redeprecipitated in methanol, and the precipitate was washed with methanol and then vacuum dried for 48 hours.

[0048] The final product was subjected to DSC testing to determine the glass transition temperature and GPC to determine its molecular weight.

[0049] Polymerization yielded 9.9g of a terpolymer, which was then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 61.2%, the conversion rate of cyclohexene oxide was 80.3%, and the glass transition temperature of the product (T) was [missing value]. g The temperature was 82.2℃, and the single transformation (see...) Figure 1This indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0050] Example 2

[0051] In a glove box, add 11.6 mg of catalyst, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 3 mL of PO, 7 mL of CHO, and 5 mL of DCM to a 50 mL autoclave. Seal the autoclave and remove it, then pressurize it to 3 MPa with CO2. Place the autoclave in an 85°C water bath. After the temperature stabilizes, pressurize it to 4 MPa with CO2 and start the reaction timer. During the reaction, control the pressure drop to within 0.2 MPa; if the pressure is insufficient, replenish it promptly.

[0052] After reacting for 12 hours, the reactor was placed in an ice-water mixture to terminate the reaction. Once the reactor temperature was below 20°C, the pressure was slowly released to atmospheric pressure, and samples of the crude product were taken for further analysis. 1 H-NMR was used to determine the conversion rate of epoxy monomers. The crude product was redeprecipitated in methanol, and the precipitate was washed with methanol and then vacuum dried for 48 hours. The final product was subjected to DSC to determine the glass transition temperature and GPC to determine its molecular weight.

[0053] 14.5g of terpolymer was obtained by polymerization, and then... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 99%, the conversion rate of cyclohexene oxide was 99.5%, and the glass transition temperature of the product (T) was [missing information]. g The temperatures are 27℃ and 100℃, with dual transformation (see...). Figure 2 The product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0054] Example 3

[0055] In a glove box, add 11.6 mg of catalyst, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 7 mL of PO, 0.5 mL of CHO and 7.5 mL of dioxane to a 50 mL autoclave. After sealing the autoclave, remove it and pressurize it to 3 MPa with CO2.

[0056] The reactor was placed in a 60°C water bath. After the temperature stabilized, it was pressurized to 4 MPa with CO2, and the reaction time was started. During the reaction, the pressure drop was controlled within 0.2 MPa, and pressure was added promptly if necessary. After 12 hours of reaction, the reactor was placed in an ice-water mixture to terminate the reaction. Once the reactor temperature was below 20°C, the pressure was slowly released to atmospheric pressure. Samples of the obtained crude product were taken for further analysis. 1 ¹H-NMR analysis was used to determine the epoxy monomer conversion rate and carbonate unit content. The crude product was redeprecipitated in methanol, and the precipitate was washed with methanol and then vacuum dried for 48 hours. The final product was subjected to DSC analysis to determine the glass transition temperature and GPC analysis to determine its molecular weight.

[0057] 12.2 g of terpolymer was obtained by polymerization, and then... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 82.3%, the conversion rate of cyclohexene oxide was 99%, and the glass transition temperature of the product (T) was [missing information]. g The temperature was 39.1℃, and the single transformation indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0058] Example 4

[0059] In a glove box, add 11.6 mg of catalyst, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 1 mL of PO, 7 mL of CHO, 5 mL of DCM, and 2 mL of chloroform to a 50 mL autoclave. After sealing the autoclave, remove it and pressurize it to 3 MPa with CO2.

[0060] The reactor was placed in a 95°C water bath. After the temperature stabilized, it was pressurized to 4 MPa with CO2, and the reaction time was started. During the reaction, the pressure drop was controlled within 0.2 MPa, and pressure was added promptly if necessary. After 12 hours of reaction, the reactor was placed in an ice-water mixture to terminate the reaction. Once the reactor temperature was below 20°C, the pressure was slowly released to atmospheric pressure. Samples of the obtained crude product were taken for further analysis. 1 H-NMR was used to determine the conversion rate of epoxy monomers. The crude product was redeprecipitated in methanol, and the precipitate was washed with methanol and then vacuum dried for 48 hours. The final product was subjected to DSC to determine the glass transition temperature and GPC to determine its molecular weight.

[0061] Polymerization yielded 11.2 g of a terpolymer. ¹H-NMR analysis showed a propylene oxide conversion of 99.5% and a cyclohexene oxide conversion of 99%. The glass transition temperature (Tg) of the product was [not specified]. g The temperatures were 30℃ and 102.6℃. The double transformation indicates that the product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0062] Example 5

[0063] This embodiment is basically the same as embodiment 1, the only difference being that the temperature of the water bath is changed:

[0064] The water bath is set to a temperature of 50℃.

[0065] The polymerization yields a random copolymer, which is then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 11.3%, the conversion rate of cyclohexene oxide was 36.4%, and the glass transition temperature of the product (T0) was [missing value]. g The temperature was 93.5℃, and the single transformation indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0066] Example 6

[0067] This embodiment is basically the same as embodiment 1, the only difference being that the temperature of the water bath is changed:

[0068] The water bath is set to a temperature of 70℃.

[0069] The polymerization yields a random copolymer, which is then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 75.2%, the conversion rate of cyclohexene oxide was 95%, and the glass transition temperature of the product (T) was [missing information]. g The temperature was 68.0℃, and the single transformation indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0070] Example 7

[0071] This embodiment is basically the same as Embodiment 2, the only difference being that the temperature of the water bath is changed:

[0072] The water bath is set to a temperature of 80℃.

[0073] The polymerization yielded a terpolymer, and 1H-NMR analysis showed that the conversion rate of propylene oxide was 93.4%, the conversion rate of cyclohexene oxide was 99%, and the glass transition temperature of the product (T0) was [missing value]. g The temperatures were 29℃ and 102℃. The double transformation indicates that the product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0074] Example 8

[0075] This embodiment is basically the same as Embodiment 2, the only difference being that the temperature of the water bath is changed:

[0076] The water bath is set to a temperature of 100℃.

[0077] The polymerization yielded a terpolymer, and 1H-NMR analysis showed that the conversion rates of propylene oxide and cyclohexene oxide were both 100%. The glass transition temperature (T0) of the product was [not specified]. g The temperatures were 31℃ and 105℃. The double transformation indicates that the product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0078] Example 9

[0079] This embodiment is basically the same as embodiment 1, with the only difference being:

[0080] Replace CHO with epoxide, keeping the dosage unchanged;

[0081] The polymerization yielded a terpolymer. ¹H-NMR analysis showed a propylene oxide conversion of 72% and a butane oxide conversion of 31.6%. The glass transition temperature (Tg) of the product was [not specified]. g The temperature was 22℃. The single transformation indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0082] Example 10

[0083] This embodiment is basically the same as embodiment 2, with the only difference being:

[0084] The amount of raw materials used in the autoclave was changed: CHO was replaced with epoxide butane, while the amount remained the same.

[0085] The polymerization yields a terpolymer, which is then subjected to... 1 H-NMR analysis showed that the conversion rates of propylene oxide and butane oxide were 99% and 95.5%, respectively, and the glass transition temperatures (T0) of the products were [not specified]. g The temperature was 15℃. The single transformation indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0086] As can be seen from the products obtained in Examples 1, 2, 9, and 10, when the type of raw material is changed, such as replacing CHO with epoxide, random copolymers can still be generated, but the temperature cannot be used to control the generated product.

[0087] Example 11

[0088] This embodiment is basically the same as embodiment 4, with the only difference being:

[0089] Chloroform was used instead of DCM as the solvent.

[0090] Polymerization yielded 5.2g of a terpolymer, which was then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 52.6%, the conversion rate of cyclohexene oxide was 66.3%, and the glass transition temperature of the product (T) was [missing value]. g The glass transition temperatures were 23℃ and 86℃, indicating that the product is a block copolymer. The glass transition temperature is mainly due to the low molecular weight of the carbonate content. The carbonate content test results are shown in Table 1.

[0091] A comparison between Examples 11 and 4 shows that different types of solvents have an impact on the preparation of the finished product.

[0092] Example 12

[0093] This embodiment is basically the same as embodiment 4, with the only difference being:

[0094] Change the material ratio in the glove box: Add 11.6 mg of catalyst 2, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 7 mL of PO, 1 mL of CHO, 5 mL of DCM, and 2 mL of chloroform to a 50 mL autoclave.

[0095] The polymerization yields a terpolymer, which is then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 100%, the conversion rate of cyclohexene oxide was 99.5%, and the glass transition temperature of the product (T) was [missing information].g The temperatures were 25℃ and 108℃. The double transformation indicates that the product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0096] Example 13

[0097] This embodiment is basically the same as embodiment 4, with the only difference being:

[0098] Change the material ratio in the glove box: Add 11.6 mg of catalyst 2, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 0.5 mL of PO, 9.5 mL of CHO, 8 mL of DCM, and 2 mL of chloroform to a 50 mL autoclave.

[0099] The polymerization yielded a terpolymer, and 1H-NMR analysis showed that the conversion of propylene oxide was 100%, the conversion of cyclohexene oxide was 99%, and the glass transition temperature of the product (T0) was [missing value]. g The temperatures were 13℃ and 107℃. The double transformation indicates that the product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0100] Example 14

[0101] In a glove box, add 11.6 mg of catalyst, 5.7 mg of bis(triphenylphosphine)ammonium chloride (PPNCl), 1 mL of PO, 7 mL of CHO, 5 mL of propylene carbonate, and 2 mL of chloroform to a 50 mL autoclave. After sealing the autoclave, remove it and pressurize it to 3 MPa with CO2.

[0102] The reactor was placed in a 95°C water bath. After the temperature stabilized, it was pressurized to 4 MPa with CO2, and the reaction time was started. During the reaction, the pressure drop was controlled within 0.2 MPa, and pressure was added promptly if necessary. After 12 hours of reaction, the reactor was placed in an ice-water mixture to terminate the reaction. Once the reactor temperature was below 20°C, the pressure was slowly released to atmospheric pressure. The crude product was sampled and analyzed by 1H-NMR to determine the conversion rate of the epoxy monomer. The crude product was redeprecipitated in methanol, and the precipitate was washed with methanol and then vacuum dried for 48 hours. The final product was analyzed by DSC to determine the glass transition temperature, and its molecular weight was determined by GPC.

[0103] Polymerization yielded 6.1 g of a terpolymer, which was then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 13%, the conversion rate of cyclohexene oxide was 57.3%, and the glass transition temperature of the product (T) was [missing value]. g The temperature was 97℃, and the double transformation indicates that the product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0104] From the data of Examples 4, 12, 13 and 14, it can be seen that the raw material ratio used in the preparation of block copolymer is preferably as shown in Example 4. When the ratio of raw materials changes compared with Example 4, a product can be obtained, but the properties of the obtained product are inferior to those of Example 4 in terms of glass transition temperature. The raw material ratio provided in Example 4 is the preferred raw material ratio.

[0105] Example 15

[0106] This embodiment is basically the same as Embodiment 1, with the only difference being:

[0107] After the autoclave is sealed, it is pressurized with CO2 to 5.0 MPa. After the temperature stabilizes, the CO2 is pressurized to 7.5 MPa.

[0108] Polymerization yielded 5.7g of a terpolymer, which was then subjected to... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 33.6%, the conversion rate of cyclohexene oxide was 39.3%, and the glass transition temperature (Tg) of the product was 86.6℃. (See [link to H-NMR analysis]). Figure 1 This indicates that the product is a random copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0109] Example 16

[0110] This embodiment is basically the same as embodiment 2, with the only difference being:

[0111] After the autoclave is sealed, it is pressurized with CO2 to 5.0 MPa. After the temperature stabilizes, the pressure is increased to 8.0 MPa.

[0112] 10.9g of terpolymer, after... 1 H-NMR analysis showed that the conversion rate of propylene oxide was 65.2%, the conversion rate of cyclohexene oxide was 63.1%, and the glass transition temperature of the product (T) was [not specified]. g The temperatures are 29℃ and 102℃, with dual transformation (see...). Figure 2 The product is a block copolymer. The molecular weight and carbonate content test results are shown in Table 1.

[0113] Data from Examples 1, 2, 15, and 16 show that the copolymer can be prepared under pressure, but increasing the pressure leads to a decrease in the conversion rate of raw materials.

[0114] The copolymers obtained in Examples 1 to 16 were tested for molecular weight and carbonate content, and the data are shown in Table 1.

[0115] Table 1. Molecular weight and carbonate content data of the copolymers obtained in Examples 1-16

[0116]

[0117] As shown in Table 1, among the compounds prepared in the various embodiments of the present invention, the random copolymer prepared in Example 1 has the best overall performance, i.e., higher carbonate content and better copolymerization degree, while the block compound prepared in Example 2 has the best overall performance, i.e., higher carbonate content and better copolymerization degree.

[0118] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A controlled polymerization method for a carbon dioxide / propylene oxide / cyclohexene oxide copolymer, characterized in that: include, In a glove box, add 11.6 mg of catalyst, 5.7 mg of bis(triphenylphosphine)ammonium chloride, 1 mL of propylene oxide, 7 mL of cyclohexene oxide, 5 mL of dichloromethane, and 2 mL of chloroform to a 50 mL autoclave. After sealing the autoclave, remove it and pressurize it to 3 MPa with CO2. Place the vessel in a 95℃ water bath. After the temperature stabilizes, pressurize it to 4MPa with CO2 and start the reaction timing. During the reaction, the pressure drop should be controlled within 0.2MPa. If the pressure is insufficient, pressurize it in time. After reacting for 12 hours, the reactor was placed in an ice-water mixture to terminate the reaction. Once the reactor temperature was below 20°C, the pressure was slowly released to atmospheric pressure to obtain the crude product. The catalyst is a porphyrin aluminum catalyst, and its structural formula is:

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