ALIPHATIC COPOLYCARBONATE AND PREPARATION METHOD THEREOF

Abstract

An aliphatic copolycarbonate and a preparation method thereof are disclosed. The aliphatic copolycarbonate contains a structural unit represented by formula (1) and a structural unit represented by formula (2):

##STR00001##

where R.sub.1 is a C.sub.3-C.sub.10 alkylene group, and R.sub.2 is an alicyclic group. In the present disclosure, a specific alicyclic monomer is introduced into the aliphatic polycarbonate molecular chain to obtain a novel aliphatic copolycarbonate. The polymer in the present disclosure has properties such as relatively high melting point, glass transition temperature and thermal stability, and has better thermal properties.

Claims

1. An aliphatic copolycarbonate comprising a structural unit represented by formula (1) and a structural unit represented by formula (2): ##STR00044## wherein R.sub.1 is a C.sub.3-C.sub.10 alkylene group, and R.sub.2 is an alicyclic group.

2. The aliphatic copolycarbonate of claim 1, wherein R.sub.1 is a C.sub.3-C.sub.10 straight-chain alkylene.

3. The aliphatic copolycarbonate of claim 2, wherein R.sub.1 is a C.sub.4, C.sub.6, C.sub.8, or C.sub.10 straight-chain alkylene.

4. The aliphatic copolycarbonate of claim 2, wherein R.sub.2 is one or more selected from the following alicyclic groups: ##STR00045##

5. The aliphatic copolycarbonate of claim 1, wherein based on a total molar amount of structural units in the aliphatic copolycarbonate as 100%, a molar content of the structural unit represented by formula (1) is 10%-90%, and a molar content of the structural unit represented by formula (2) is 10%-90%; wherein when R.sub.2 is ##STR00046##  the molar content of the structural unit represented by the formula (1) is 10%-80%, and the molar content of the structural unit represented by the formula (2) is 20%-90%; when R.sub.2 is ##STR00047##  the molar content of the structural unit represented by the formula (1) is 10%-80%, and the molar content of the structural unit represented by the formula (2) is 20%-90%; when R.sub.2 is ##STR00048##  the molar content of the structural unit represented by the formula (1) is 10%-60%, and the molar content of the structural unit represented by the formula (2) is 40%-90%; and when R.sub.2 is ##STR00049##  the molar content of the structural unit represented by the formula (1) is 10%-70%, and the molar content of the structural unit represented by the formula (2) is 30%-90%.

6. The aliphatic copolycarbonate of claim 1, wherein a weight-average molecular weight of the aliphatic copolycarbonate is 9×10.sup.3-14×10.sup.4; wherein when R.sub.2 is ##STR00050##  the weight-average molecular weight of the aliphatic copolycarbonate is 3×10.sup.4-14×10.sup.4; when R.sub.2 is ##STR00051##  the weight-average molecular weight of the aliphatic copolycarbonate is 8×10.sup.4-14×10.sup.4; when R.sub.2 is ##STR00052##  the weight-average molecular weight of the aliphatic copolycarbonate is 2×10.sup.4-14×10.sup.4; and when R.sub.2 is ##STR00053##  the weight-average molecular weight of the aliphatic copolycarbonate is 3×10.sup.4-14×10.sup.4.

7. The aliphatic copolycarbonate of claim 6, wherein the weight-average molecular weight of the aliphatic copolycarbonate is 2×10.sup.4-14×10.sup.4.

8. The aliphatic copolycarbonate of claim 1, wherein a number-average molecular weight of the aliphatic copolycarbonate is 5×10.sup.3-8×10.sup.4; wherein when R.sub.2 is ##STR00054##  the number-average molecular weight of the aliphatic copolycarbonate is 2×10.sup.4-8×10.sup.4; when R.sub.2 is ##STR00055##  the number-average molecular weight of the aliphatic copolycarbonate is 4×10.sup.4-8×10.sup.4; when R.sub.2 is ##STR00056##  the number-average molecular weight of the aliphatic copolycarbonate is 1×10.sup.4-8×10.sup.4; and when R.sub.2 is ##STR00057##  the number-average molecular weight of the aliphatic copolycarbonate is 1×10.sup.4-8×10.sup.4.

9. The aliphatic copolycarbonate of claim 8, wherein the number-average molecular weight of the aliphatic copolycarbonate is 1×10.sup.4-8×10.sup.4.

10. The aliphatic copolycarbonate of claim 8, wherein a polydispersity index of the aliphatic copolycarbonate is 1.5-2.1.

11. The aliphatic copolycarbonate of claim 10, wherein the polydispersity index of the aliphatic copolycarbonate is 1.59-1.89.

12. The aliphatic copolycarbonate of claim 1, wherein a glass transition temperature of the aliphatic copolycarbonate is (−30.29)-70.9° C., as measured and analyzed by differential scanning; by thermogravimetric measurement and analysis, a 5% thermal weight loss temperature of the aliphatic copolycarbonate is 270.71-330.79° C.; by the thermogravimetric measurement and analysis, a maximum thermogravimetric rate temperature of the aliphatic copolycarbonate is 306.73-392.45° C.

13. The aliphatic copolycarbonate of claim 12, wherein the glass transition temperature of the aliphatic copolycarbonate is 0-70.90° C., wherein the 5% thermal weight loss temperature of the aliphatic copolycarbonate is 271-330° C., and wherein the maximum thermogravimetric rate temperature of the aliphatic copolycarbonate is 307-392° C.

14. A method for preparing the aliphatic copolycarbonate of claim 1, comprising: (1) subjecting the diol monomer represented by formula (3), the diol monomer represented by formula (4), and a carbonate monomer to melt polycondensation in the presence of a catalyst and in an inert atmosphere to obtain a prepolymerized product; ##STR00058## (2) removing by-products in the prepolymerized product obtained in operation (1), and then performing a polymerization reaction to obtain the aliphatic copolycarbonate.

15. The method of claim 14, wherein conditions for the pre-polymerization in operation (1) comprise: the temperature is 140-220° C., and/or, the reaction time is 1-5 hours; and/or, the inert atmosphere is provided by nitrogen and/or an inert gas; and/or, wherein conditions for polymerization in operation (2) comprise: the temperature is 150-240° C., and/or, the time is 1-5 hours, and/or, the pressure is not higher than 200 Pa; and/or, the method for removing the by-products in the prepolymerized product obtained in operation (1) is vacuum distillation, wherein the temperature of the vacuum distillation is 150-240° C., and the pressure is 2×10.sup.2-2×10.sup.4 Pa.

16. The method of claim 15, wherein in the conditions for polymerization in operation (2), the pressure is 10-150 Pa.

17. The method of claim 14, wherein a ratio of a total molar amount of the carbonate monomer to a total molar amount of the diol monomer represented by formula (3) and the diol monomer represented by formula (4) is 1:(1-1.5); and/or, the diol monomer represented by formula (4) is selected as at least one of the following compounds: ##STR00059##  and/or, the carbonate monomer is selected from at least one of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dihexyl carbonate, dioctyl carbonate, ethyl methyl carbonate, and diphenyl carbonate.

18. The method of claim 14, wherein the catalyst is one or more selected from the group consisting of oxide-type solid bases, inorganic metal salts and organic bases; and/or, based on a total molar amount of the diol monomer represented by formula (3) and the diol monomer represented by formula (4) or the molar amount of the carbonate monomer as 100 parts, the amount of the catalyst used is 0.1-1 part.

Description

DETAILED DESCRIPTION

[0065] The technical solutions of the present disclosure will be described below in a definite and comprehensive manner with reference to specific embodiments. Apparently, the described embodiments are merely some of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall in the scope of protection of the present disclosure.

[0066] It should be noted:

[0067] In the present invention, unless otherwise specified, all the embodiments and illustrated implementations mentioned herein may be combined with each other to form new technical solutions.

[0068] In the present disclosure, unless otherwise specified, all the technical features and illustrated features mentioned herein may be combined with each other to form new technical solutions.

[0069] A “range” disclosed herein may be in the form of a lower limit and an upper limit, which may be one or more lower limits, and one or more upper limits, respectively.

[0070] Unless otherwise defined, professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods or materials similar or equivalent to those described may also be used in the present disclosure.

[0071] The present disclosure will be specifically described below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present disclosure, and should not be construed as limitations on the protection scope of the present disclosure. Some non-essential improvements and adjustments made to the present disclosure by those skilled in the art according to the contents of the present disclosure still belong to the scope of protection of the present disclosure.

[0072] In the following examples and comparative examples, unless otherwise specified, the structural formula of tricyclodecanedimethanol is

##STR00040##

the structural formula of 1,4-cyclohexanedimethanol is

##STR00041##

the structural formula of 4,4′-bicyclohexanol is

##STR00042##

the structural formula of 2,2,4,4-tetramethyl-1,3-cyclobutanediol is

##STR00043##

The above are all commercially available products.

[0073] The embodiments of the present disclosure are described with specific examples, and the results of each example are tested accordingly. Gel permeation chromatography (GPC) is used to measure the molecular weight and polydispersity of the polymer, and polystyrene is the standard sample and tetrahydrofuran is the mobile phase. The thermal properties and thermal stability of the polymers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively.

Embodiment 1

[0074] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.9:0.1) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product.

[0075] Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1.1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0076] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 124797 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 72976 g.Math.mol.sup.−1, and the PDI is 1.71.

[0077] According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of −3.43° C.

[0078] According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 283.98° C., the maximum thermal weight loss rate temperature T.sub.d,max1 is 314.09° C., T.sub.d,max2 is 358.03° C.

Embodiment 2

[0079] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.8:0.2) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (110 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0080] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 116320 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 67735 g.Math.mol.sup.−1, and the PDI is 1.72. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 17.08° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 306.72° C., the maximum thermal weight loss rate temperature T.sub.d,max1 is 336.23° C., T.sub.d,max2 is 381.20° C.

Embodiment 3

[0081] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.7:0.3) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (120 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0082] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 105969 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 61231 g.Math.mol.sup.−1, and the PDI is 1.73. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 28.63° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 300.46° C., the maximum thermal weight loss rate temperature T.sub.d,max1 is 321.39° C., T.sub.d,max2 is 383.78° C.

Embodiment 4

[0083] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.6:0.4) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1.1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (90 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0084] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 73616 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 43301 g.Math.mol.sup.−1, and the PDI is 1.70. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 37.11° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 294.44° C., the maximum thermal weight loss rate temperature T.sub.d,max1 is 331.40° C., T.sub.d,max2 is 373.26° C.

Embodiment 5

[0085] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.5:0.5) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1.2 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (130 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tri cyclodecane dimethanol carbonate) is obtained.

[0086] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 35659 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 21772 g.Math.mol.sup.−1, and the PDI is 1.64. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 43.83° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 317.28° C., the maximum thermal weight loss rate temperature T.sub.d,max is 390.36° C.

Embodiment 6

[0087] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.4:0.6) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (110 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0088] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 26335 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 16197 g.Math.mol.sup.−1, and the PDI is 1.63. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 52.48° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 314.64° C., the maximum thermal weight loss rate temperature T.sub.d,max is 388.72° C.

Embodiment 7

[0089] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.3:0.7) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1.1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0090] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 29003 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 17813 g.Math.mol.sup.−1, and the PDI is 1.63. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 64.18° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 307.48° C., the maximum thermal weight loss rate temperature T.sub.d,max is 375.05° C.

Embodiment 8

[0091] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.2:0.8) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1.1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0092] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 12369 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 7756 g.Math.mol.sup.−1, and the PDI is 1.59. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 66.65° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 332.28° C., the maximum thermal weight loss rate temperature T.sub.d,max is 392.45° C.

Embodiment 9

[0093] Diphenyl carbonate, 1,4-butanediol and tricyclodecane dimethanol (mol ratio is 1:0.1:0.9) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.25% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1.1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (90 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-tricyclodecane dimethanol carbonate) is obtained.

[0094] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 10451 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 6331 g.Math.mol.sup.−1, and the PDI is 1.65. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 70.90° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 327.41° C., the maximum thermal weight loss rate temperature T.sub.d,max is 379.99° C.

Embodiment 10

[0095] Diphenyl carbonate, 1,4-butanediol and 1,4-cyclohexanedimethanol (mol ratio is 1:0.9:0.1) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (80 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-1,4-cyclohexanedimethanol carbonate) is obtained.

[0096] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 83506 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 48263 g.Math.mol.sup.−1, and the PDI is 1.73. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of −17.85° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 294.03° C., the maximum thermal weight loss rate temperature T.sub.d,max is 332.12° C.

Embodiment 11

[0097] Diphenyl carbonate, 1,4-butanediol and 1,4-cyclohexanedimethanol (mol ratio is 1:0.7:0.3) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (80 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-1,4-cyclohexanedimethanol carbonate) is obtained.

[0098] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 102836 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 56720 g.Math.mol.sup.−1, and the PDI is 1.81. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 1.28° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 313.01° C., the maximum thermal weight loss rate temperature T.sub.d,max is 356.17° C.

Embodiment 12

[0099] Diphenyl carbonate, 1,4-butanediol and 1,4-cyclohexanedimethanol (mol ratio is 1:0.5:0.5) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (90 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-1,4-cyclohexanedimethanol carbonate) is obtained.

[0100] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 100852 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 53356 g.Math.mol.sup.−1, and the PDI is 1.89. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 16.78° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 320.71° C., the maximum thermal weight loss rate temperature T.sub.d,max is 365.94° C.

Embodiment 13

[0101] Diphenyl carbonate, 1,4-butanediol and 1,4-cyclohexanedimethanol (mol ratio is 1:0.3:0.7) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (80 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-1,4-cyclohexanedimethanol carbonate) is obtained.

[0102] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 141555 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 77061 g.Math.mol.sup.−1, and the PDI is 1.84. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 30.14° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 313.95° C., the maximum thermal weight loss rate temperature T.sub.d,max is 370.10° C.

Embodiment 14

[0103] Diphenyl carbonate, 1,4-butanediol and 1,4-cyclohexanedimethanol (mol ratio is 1:0.1:0.9) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (80 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-1,4-cyclohexanedimethanol carbonate) is obtained.

[0104] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 113326 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 62186 g.Math.mol.sup.−1, and the PDI is 1.82. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 42.34° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 330.79° C., the maximum thermal weight loss rate temperature T.sub.d,max is 371.61° C.

Embodiment 15

[0105] Diphenyl carbonate, 1,4-butanediol, and 4,4′-bicyclohexanol (mol ratio is 1:0.9:0.1) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-4,4′-bicyclohexanol carbonate) is obtained.

[0106] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 31744 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 18893 g.Math.mol.sup.−1, and the PDI is 1.68. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of −14.18° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 274.26° C., the maximum thermal weight loss rate temperature T.sub.d,max is 306.73° C.

Embodiment 16

[0107] Diphenyl carbonate, 1,4-butanediol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (mol ratio is 1:0.9:0.1) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 190° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 210° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-2,2,4,4-tetramethyl-1,3-cyclobutanediol carbonate) is obtained.

[0108] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 23958 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 14919 g.Math.mol.sup.−1, and the PDI is 1.61. According to DSC measurement and analysis, the melting point of the copolycarbonate is 41.81° C., the melting enthalpy ΔH.sub.m is 7.94 J/g, and the glass transition temperature is −30.29° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 270.71° C., the maximum thermal weight loss rate temperature T.sub.d,max is 311.84° C.

Embodiment 17

[0109] Diphenyl carbonate, 1,4-butanediol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (mol ratio is 1:0.7:0.3) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 190° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 210° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-2,2,4,4-tetramethyl-1,3-cyclobutanediol carbonate) is obtained.

[0110] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 18054 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 10639 g.Math.mol.sup.−1, and the PDI is 1.70. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of −12.53° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 279.11° C., the maximum thermal weight loss rate temperature T.sub.d,max is 315.42° C.

Embodiment 18

[0111] Diphenyl carbonate, 1,4-butanediol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (mol ratio is 1:0.5:0.5) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 190° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 210° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (90 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-2,2,4,4-tetramethyl-1,3-cyclobutanediol carbonate) is obtained.

[0112] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 13722 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 8406 g.Math.mol.sup.−1, and the PDI is 1.63. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 11.53° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 295.58° C., the maximum thermal weight loss rate temperature T.sub.d,max is 329.22° C.

Embodiment 19

[0113] Diphenyl carbonate, 1,4-butanediol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (mol ratio is 1:0.3:0.7) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 190° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 210° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (100 Pa) for polycondensation, and the reaction is carried out. After 2 hours, an aliphatic copolycarbonate-poly(butylene carbonate-co-2,2,4,4-tetramethyl-1,3-cyclobutanediol carbonate) is obtained.

[0114] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 9012 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 5380 g.Math.mol.sup.−1, and the PDI is 1.68. According to DSC measurement and analysis, the copolycarbonate has an amorphous state, no fixed melting point, and a glass transition temperature of 31.55° C. According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 307.37° C., the maximum thermal weight loss rate temperature T.sub.d,max is 342.43° C.

Embodiment 20

[0115] The aliphatic copolycarbonate is prepared according to the method of Embodiment 13, except that the process is replaced by the following method: Diphenyl carbonate, 1,4-butanediol and 1,4-cyclohexanedimethanol (mol ratio is 1:0.3:0.7) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 210° C., and the reaction time is 2 hours to obtain an oligomerized product. The temperature of the oligomerized product is raised to 220° C., and the pressure in the reactor was gradually lowered to about 500 Pa, and the reaction was continued for 2 hours. The obtained product was measured by GPC to find that he weight-average molecular weight M.sub.w is 35304 g.Math.mol.sup.−1, and the number-average molecular weight is M.sub.n was 17349 g.Math.mol.sup.−1, and PDI was 2.03.

Comparison Embodiment

[0116] Diphenyl carbonatebutanediol and 1,4-butanediol (mol ratio is 1:1) are placed in the reactor simultaneously, and magnesium oxide is added as a catalyst (the dosage is 0.15% of the total moles of carbonate monomers or diol monomers). Under a high-purity nitrogen atmosphere, they are subjected to heating, melting and mixing uniformly, thus raising the temperature to 200° C., and the reaction time is 2 hours to obtain an oligomerized product. Raise the temperature of the oligomerized product to 220° C., and at the same time gradually reduce the pressure in the reactor to 1 KPa. After the by-products are distilled off under reduced pressure, reduce the pressure in the reactor to below 200 Pa (90 Pa) for polycondensation, and the reaction is carried out. After 2 hours, polybutylene carbonate is obtained.

[0117] According to GPC measurement and analysis, the weight-average molecular weight M.sub.w of the copolycarbonate obtained in this example is 129660 g.Math.mol.sup.−1, the number-average molecular weight M.sub.n is 93498 g.Math.mol.sup.−1, and the PDI is 1.39. The melting point of the polycarbonate is 61.15° C., the melting enthalpy ΔH.sub.m is 66.56 J/g, and the glass transition temperature is −30.28° C.

[0118] According to TG measurement and analysis, the 5% thermal weight loss temperature T.sub.d,5% of the product is 285.24° C., the maximum thermal weight loss rate temperature T.sub.d,max is 323.93° C.

[0119] Compared with the polybutylene carbonate obtained in the comparative example, the glass transition temperature and thermal stability of the copolycarbonate obtained in the embodiments of the present disclosure have been significantly improved. In particular, the copolycarbonates obtained in Embodiments 2-4 and 10-14 have relatively high molecular weights while improving the thermal properties.

[0120] By comparing the Comparison embodiment with Embodiment 3 and Embodiment 13, it can be seen that under the condition of similar molecular weights, the glass transition temperature of Embodiment 3 and Embodiment 13 is increased by nearly 60° C., and the Td, 5% also increased to above 300° C., and the thermal performance is significantly improved.

[0121] Finally, it should be noted that the above embodiments are merely used to illustrate the technical solutions of the present disclosure, but not to limit them. Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that the technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced. However, these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present disclosure.