Hyperbranched carbon dioxide-based polycarbonate as well as preparation method and application thereof

Abstract

The invention belongs to the field of polymer chemistry, and relates to hyperbranched carbon dioxide-based polycarbonate as well as a preparation method and application thereof. The hyperbranched carbon dioxide-based polycarbonate is prepared by self-condensation polymerization of a monomer as shown in a formula I; in the # imgabs 0 # formula I, the # imgabs 1 # is a three-arm structural unit derived from an initiator; and the # imgabS2 # is a carbon dioxide-based polycarbonate chain segment obtained by ring-opening addition polymerization of epoxide and carbon dioxide. Compared with the prior art, the hyperbranched carbon dioxide-based polycarbonate and the preparation method thereof have the following advantages that a mixture of a triethyl borane catalyst and one or two of TBD or DBU is adopted as a catalyst to efficiently catalyze copolymerization of carbon dioxide and an epoxide monomer to prepare hyperbranched carbon dioxide-based polycarbonate with a new structure, and the glass-transition temperature and the fat dissolving performance of a polymer are improved.

Description

Technical Field

[0001] The invention belongs to the field of polymer chemistry, and in particular relates to a hyperbranched carbon dioxide-based polycarbonate and a preparation method and application thereof. Background Art

[0002] Hyperbranched polymers are usually composed of AB x Prepared by self-condensation reaction of monomers. x The monomer molecule contains at least two B functional groups and one A functional group, and A and B must be able to react, so that they can be gradually expanded to hyperbranched polyesters with a large number of branched structures through continuous self-condensation.

[0003] Carbon dioxide-based polycarbonate is a completely degradable and environmentally friendly plastic synthesized from carbon dioxide and epoxide. It is completely biodegradable and will not pollute the environment. It can be used in elastomers, coatings, synthetic leather, safety glass, surface coatings (resins, leather, etc.), soles, photoresists, adhesives, magnetic adhesives, conveyor belts, etc. However, the application of traditional polypropylene carbonate in engineering plastics and medical fields is limited due to its glass transition temperature close to room temperature and poor processing performance. It is urgent to develop new carbon dioxide-based polycarbonate materials to expand new application directions. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing and applying a hyperbranched carbon dioxide-based polycarbonate, so as to solve the problems of the prior art polypropylene carbonate and the like having a simple structure, a low glass transition temperature, a limited application range, and the like.

[0005] In order to achieve the above object, the first aspect of the present invention provides a hyperbranched carbon dioxide-based polycarbonate, wherein the hyperbranched carbon dioxide-based polycarbonate is prepared by a self-condensation reaction of a monomer represented by formula I;

[0006]

[0007] In Formula I, is a three-arm structural unit derived from an initiator;

[0008] The carbon dioxide-based polycarbonate chain segment is obtained by ring-opening addition polymerization of epoxide and carbon dioxide.

[0009] The second aspect of the present invention provides a method for preparing the hyperbranched carbon dioxide-based polycarbonate, comprising the following steps:

[0010] Under polymerization reaction conditions, epoxide, carbon dioxide, a catalyst and an initiator are contacted and reacted to obtain the hyperbranched carbon dioxide-based polycarbonate.

[0011] The third aspect of the present invention provides an application of the hyperbranched carbon dioxide-based polycarbonate in degradable plastics.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] The invention adopts a mixture of triethylborane catalyst and TBD or DBU or both as catalyst to efficiently catalyze the copolymerization of carbon dioxide and epoxide monomers to prepare a hyperbranched carbon dioxide-based polycarbonate with a new structure, thereby improving the glass transition temperature and fat-dissolving performance of the polymer.

[0014] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0015] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0016] In order to achieve the above object, the first aspect of the present invention provides a hyperbranched carbon dioxide-based polycarbonate, wherein the hyperbranched carbon dioxide-based polycarbonate is prepared by a self-condensation reaction of a monomer represented by formula I;

[0017]

[0018] In Formula I, is a three-arm structural unit derived from an initiator;

[0019] The carbon dioxide-based polycarbonate chain segment is obtained by ring-opening addition polymerization of epoxide and carbon dioxide.

[0020] According to the present invention, preferably, the initiator is 2,2-dimethylolbutyric acid.

[0021] According to the present invention, preferably, the carbon dioxide-based polycarbonate segment is as shown in Formula II:

[0022]

[0023] In formula II, R1 and R2 are each independently at least one of H, a C1-C10 alkyl group, a C1-C10 ester group and a C1-C10 ether group, or R1 and R2 form a cycloalkenyl group or a cycloalkyl group, n is an integer of 50-2500, and m is an integer of 0-10.

[0024] According to the present invention, preferably, the epoxide is selected from at least one of propylene oxide, ethylene oxide, epichlorohydrin glycidyl ether, glycidyl ester, 1,2-butylene oxide, 2,3-butylene oxide, cyclopentane oxide, cyclohexene oxide, 3,4-epoxy-1-cyclohexene and cyclooctane oxide.

[0025] According to a specific embodiment of the present invention, when the epoxide is propylene oxide, the schematic structure of the obtained hyperbranched carbon dioxide-based polycarbonate is as follows:

[0026]

[0027] In the formula, n is an integer of 50-2500, and m is an integer of 0-10.

[0028] According to the present invention, preferably, the hyperbranched carbon dioxide-based polycarbonate has a number average molecular weight of 5000 to 250000 g / mol, preferably 10000-130000 g / mol, and a molecular weight distribution index of 1.0 to 1.60, preferably 1.12-1.35.

[0029] The second aspect of the present invention provides a method for preparing the hyperbranched carbon dioxide-based polycarbonate, comprising the following steps:

[0030] Under polymerization reaction conditions, epoxide, carbon dioxide, a catalyst and an initiator are contacted and reacted to obtain the hyperbranched carbon dioxide-based polycarbonate.

[0031] According to the present invention, preferably, the catalyst comprises a main catalyst and a co-catalyst.

[0032] According to the present invention, preferably, the main catalyst is triethylborane TEB, or triethylborane TEB and TBD and / or DBU.

[0033] According to the present invention, preferably, the co-catalyst is an ammonium salt and / or a phosphonium salt, preferably at least one selected from ammonium bromide salt, ammonium chloride salt, ammonium azide salt, iminium salt and EtPh3PBr.

[0034] According to the present invention, preferably, the molar ratio of the main catalyst to the co-catalyst is 1:(0.1-10), preferably 1:(0.5-6).

[0035] According to the present invention, preferably, the molar ratio of the epoxide to the main catalyst is 100-50000:1, preferably (500-5000):1; the molar ratio of the epoxide to the initiator is (100-2000):1, preferably (500-1000):1.

[0036] According to the present invention, preferably, the polymerization conditions include: polymerization pressure of 0.1-6 MPa, reaction time of 1-72 h, and reaction temperature of 25-100°C.

[0037] According to the present invention, preferably, after the contact reaction, a separation and purification step is also included, and the separation and purification step is at least one step of vacuuming to remove unreacted raw materials, heating to remove unreacted raw materials, dissolving the product with excess solvent, adding methanol to precipitate and centrifuging to dry.

[0038] The third aspect of the present invention provides an application of the hyperbranched carbon dioxide-based polycarbonate in degradable plastics.

[0039] The present invention will be further described below in conjunction with embodiments, but the scope of the present invention is not limited to these embodiments.

[0040] Example 1

[0041] In a 250mL autoclave, propylene oxide (0.4mol, 23.232g), 2,2-dihydroxymethylbutyric acid (0.0004mol, 0.0593g), triethylborane (0.0004mol, 0.0392g), tetrabutylammonium bromide (0.0004mol, 0.1289g) were added, the reaction device was closed, carbon dioxide was introduced and the pressure was adjusted to 2MPa, the reaction temperature was adjusted to 50°C, and after stirring the reaction for 24h, the pressure relief valve was opened to release the unreacted carbon dioxide and recover the unreacted propylene oxide, and then tetrahydrofuran was added to dissolve the polymerization product, and then methanol was added for precipitation, filtered, washed, and dried to obtain a hyperbranched carbon dioxide-based polycarbonate. The number average molecular weight of the hyperbranched carbon dioxide-based polycarbonate was tested to be 123kg / mol, and the molecular weight distribution was 1.24.

[0042] Example 2

[0043] Hyperbranched carbon dioxide-based polycarbonate was prepared according to the method of Example 1, except that propylene oxide was replaced by ethylene oxide, epichlorohydrin glycidyl ether, glycidyl ester, 1,2-butylene oxide, 2,3-butylene oxide, cyclopentane oxide, cyclohexane oxide, 3,4-epoxy-1-cyclohexene, and cyclooctane oxide. The number average molecular weights of the hyperbranched carbon dioxide-based polycarbonate tested were 103 kg / mol, 98 kg / mol, 114 kg / mol, 74 kg / mol, 87 kg / mol, 73 kg / mol, 97 kg / mol, 92 kg / mol, and 105 kg / mol, and the molecular weight distributions were 1.24, 1.13, 1.31, 1.27, 1.24, 1.43, 1.29, 1.19, and 1.25, respectively.

[0044] Example 3

[0045] Hyperbranched carbon dioxide-based polycarbonate was prepared according to the method of Example 1, except that the catalyst was replaced by TEB (0.0004 mol / TBD (0.0001 mol), TEB (0.0004 mol / DBU (0.0001 mol), TEB (0.0004 mol / TBD (0.00005 mol) / DBU (0.00005 mol). The number average molecular weight of the hyperbranched carbon dioxide-based polycarbonate was tested to be 94 kg / mol and 103 kg / mol, respectively, and the molecular weight distribution was 1.19 and 1.27, respectively.

[0046] Example 4

[0047] Hyperbranched carbon dioxide-based polycarbonate was prepared according to the method of Example 1, except that tetrabutylammonium bromide was replaced by ammonium bromide salt, ammonium chloride salt, ammonium azide salt, iminium salt and phosphonium salt. The number average molecular weight of the hyperbranched carbon dioxide-based polycarbonate was tested to be 101 kg / mol, 97 kg / mol, 74 kg / mol, 106 kg / mol and 99 kg / mol, respectively, and the molecular weight distribution was 1.17, 1.23, 1.17, 1.22 and 1.19, respectively.

[0048] Example 5

[0049] Hyperbranched CO2-based polycarbonate was prepared according to the method of Example 1, except that the amount of triethylborane was adjusted from 0.0004 mol to 0.0008 mol and 0.000008 mol. The number average molecular weights of the hyperbranched CO2-based polycarbonate were tested to be 117 kg / mol and 91 kg / mol, respectively, and the molecular weight distributions were 1.22 and 1.35, respectively.

[0050] Example 6

[0051] Hyperbranched CO2-based polycarbonate was prepared according to the method of Example 1, except that the polymerization reaction pressure was adjusted from 2 MPa to 0.1 MPa and 6 MPa. The number average molecular weights of the hyperbranched CO2-based polycarbonate were tested to be 123 kg / mol and 131 kg / mol, respectively, and the molecular weight distributions were 1.24 and 1.37, respectively.

[0052] Example 7

[0053] Hyperbranched CO2-based polycarbonate was prepared according to the method of Example 1, except that the polymerization reaction time was adjusted from 24 h to 1 h and 72 h. The number average molecular weights of the hyperbranched CO2-based polycarbonate were tested to be 21 kg / mol and 119 kg / mol, respectively, and the molecular weight distributions were 1.26 and 1.35, respectively.

[0054] Example 8

[0055] Hyperbranched CO2-based polycarbonate was prepared according to the method of Example 1, except that the polymerization reaction temperature was adjusted from 50° C. to 25° C. and 100° C. The number average molecular weights of the hyperbranched CO2-based polycarbonate were tested to be 51 kg / mol and 76 kg / mol, respectively, and the molecular weight distributions were 1.25 and 1.32, respectively.

[0056] Example 9

[0057] Hyperbranched carbon dioxide-based polycarbonate was prepared according to the method of Example 1, except that the amount of 2,2-dihydroxymethylbutyric acid was adjusted from 0.0004 mol to 0.004 mol and 0.00013 mol. The number average molecular weight of the hyperbranched carbon dioxide-based polycarbonate was tested to be 27 kg / mol and 115 kg / mol, respectively, and the molecular weight distribution was 1.18 and 1.32, respectively.

[0058] Comparative Example 1

[0059] Carbon dioxide-based polycarbonate was prepared according to the method of Example 1, except that 2,2-dihydroxymethylbutyric acid was not added to obtain carbon dioxide-based polycarbonate. The number average molecular weight of the carbon dioxide-based polycarbonate was tested to be 43 kg / mol, and the molecular weight distribution was 1.27.

[0060] Comparative Example 2

[0061] Carbon dioxide-based polycarbonate was prepared according to the method of Example 1, except that triethylborane was replaced by porphyrin zinc catalyst. The number average molecular weight of the hyperbranched carbon dioxide-based polycarbonate was tested to be 69 kg / mol, and the molecular weight distribution was 1.15.

[0062] Application Examples

[0063] Test standard for glass transition temperature. Use differential scanning calorimetry to test the glass transition temperature of the material (temperature change rate 10℃ / min)

[0064] The properties of the hyperbranched carbon dioxide-based polycarbonate obtained in Example 1 and the carbon dioxide-based polycarbonates obtained in Comparative Examples 1-3 were tested. The results are shown in Table 1.

[0065] Table 1

[0066] Glass transition temperature(℃) Example 1 52 Comparative Example 1 41 Comparative Example 2 39

[0067] It can be seen from Table 1 that, relative to the carbon dioxide-based polycarbonates of Comparative Examples 1-2, the hyperbranched carbon dioxide-based polycarbonate obtained in Example 1 has a higher glass transition temperature and better processing properties, thus broadening the application field of carbon dioxide-based polycarbonate.

[0068] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0069] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A hyperbranched carbon dioxide-based polycarbonate, characterized in that The hyperbranched carbon dioxide-based polycarbonate is prepared by self-condensation reaction of the monomers shown in formula I; In Formula I, is a three-arm structural unit derived from an initiator; The carbon dioxide-based polycarbonate chain segment is obtained by ring-opening addition polymerization of epoxide and carbon dioxide.

2. The hyperbranched carbon dioxide-based polycarbonate according to claim 1, wherein The initiator is 2,2-dimethylolbutyric acid.

3. The hyperbranched carbon dioxide-based polycarbonate according to claim 1, wherein The carbon dioxide-based polycarbonate segment is shown in Formula II: In formula II, R1 and R2 are each independently at least one of H, a C1-C10 alkyl group, a C1-C10 ester group and a C1-C10 ether group, or R1 and R2 form a cycloalkenyl group or a cycloalkyl group, n is an integer of 50-2500, and m is an integer of 0-10.

4. The hyperbranched carbon dioxide-based polycarbonate according to claim 3, wherein The epoxide is selected from at least one of propylene oxide, ethylene oxide, epichlorohydrin glycidyl ether, glycidyl ester, 1,2-butylene oxide, 2,3-butylene oxide, cyclopentane oxide, cyclohexene oxide, 3,4-epoxy-1-cyclohexene and cyclooctane oxide.

5. The hyperbranched carbon dioxide-based polycarbonate according to any one of claims 1 to 4, wherein The hyperbranched carbon dioxide-based polycarbonate has a number average molecular weight of 5,000 to 250,000 g / mol, preferably 10,000 to 130,000 g / mol, and a molecular weight distribution index of 1.0 to 1.60, preferably 1.12 to 1.

35.

6. The method for preparing a hyperbranched carbon dioxide-based polycarbonate according to any one of claims 1 to 5, characterized in that: The steps include: Under polymerization reaction conditions, epoxide, carbon dioxide, a catalyst and an initiator are contacted and reacted to obtain the hyperbranched carbon dioxide-based polycarbonate.

7. The preparation method according to claim 6, wherein: The catalyst comprises a main catalyst and a co-catalyst; the main catalyst is triethylborane TEB, or triethylborane TEB and TBD and / or DBU; The co-catalyst is an ammonium salt and / or a phosphonium salt, preferably at least one selected from ammonium bromide salt, ammonium chloride salt, ammonium azide salt, iminium salt and EtPh3PBr.

8. The preparation method according to claim 7, wherein: The molar ratio of the main catalyst to the co-catalyst is 1:(0.1-10), preferably 1:(0.5-6).

9. The preparation method according to claim 6, wherein: The molar ratio of the epoxide to the main catalyst is 100-50000:1, preferably (500-5000):1; the molar ratio of the epoxide to the initiator is (100-2000):1, preferably (500-1000):

1.

10. The preparation method according to claim 6, wherein: The polymerization conditions include: polymerization pressure of 0.1-6 MPa, reaction time of 1-72 hours, and reaction temperature of 25-100°C.

11. The preparation method according to claim 6, wherein: After the contact reaction, the method further comprises a separation and purification step, wherein the separation and purification step comprises at least one of vacuuming to remove unreacted raw materials, heating to remove unreacted raw materials, dissolving the product with an excess solvent, adding methanol to precipitate, and centrifuging and drying.

12. Use of the hyperbranched carbon dioxide-based polycarbonate according to any one of claims 1 to 6 or the hyperbranched carbon dioxide-based polycarbonate prepared by the preparation method according to any one of claims 7 to 11 in degradable plastics.

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