Preparation method of heat-resistant bisphenol A type copolycarbonate

Abstract

The invention discloses a preparation method of heat-resistant bisphenol A type copolycarbonate, and belongs to the technical field of polycarbonate synthesis. Comprising the following steps: by taking bisphenol A and diester carbonate as monomers, aromatic dibasic acid, aromatic dibasic acid ester or aromatic dihydroxy compound as a copolymerization unit and imidazole ionic liquid as a catalyst, carrying out transesterification under a protective atmosphere, and then carrying out condensation polymerization under a vacuum condition to obtain the heat-resistant bisphenol A type copolycarbonate. A metal-free catalyst is used for carrying out melt polycondensation on bisphenol A type copolycarbonate, so that efficient polymerization and heat-resistant modification of polycarbonate are realized. The performance of the copolycarbonate is regulated and controlled by controlling the type and proportion of the added copolymerization units, so that the glass-transition temperature is increased while the mechanical properties and optical properties of the bisphenol A polycarbonate are retained.

Description

Technical Field

[0001] This invention belongs to the field of polycarbonate synthesis technology, and particularly relates to a method for preparing heat-resistant bisphenol A type copolycarbonate. Background Technology

[0002] Bisphenol A type polycarbonate refers to linear polycarbonate materials synthesized using bisphenol A as a monomer. The carbonate bonds in its main chain can originate from phosgene or diphenyl carbonate, etc. Bisphenol A type polycarbonate possesses excellent comprehensive properties, mainly including high strength, high modulus, and high impact resistance. In addition, due to its wide operating temperature range, high light transmittance, low molding shrinkage during processing, and good dimensional stability, bisphenol A type polycarbonate is widely used in many fields of modern society.

[0003] The synthesis methods of bisphenol A polycarbonate are generally divided into two categories: (1) interfacial polycondensation, which requires the use of highly toxic phosgene as a monomer and produces HCl byproducts, posing a significant hazard to experimental equipment and personnel health; and (2) melt polycondensation, which uses monomers from a wide range of sources with low toxicity, in line with the development concept of green chemistry. However, the metal catalysts used in traditional melt polycondensation may cause the polymer to yellow, have a wide molecular weight distribution, and have metal residues in the polymer, limiting the application of these polymers. Common organic base catalysts are usually unable to withstand the high-temperature environment required for melt polycondensation, and thus become deactivated, failing to effectively catalyze the condensation polymerization. In addition, the glass transition temperature of bisphenol A polycarbonate is around 140°C, which cannot meet the requirements of some special application scenarios, such as aerospace, electronic equipment, and the automotive industry. Studies have shown that introducing rigid groups into polymer segments is an effective way to improve the heat resistance of polymers. Chinese patent CN113929894B discloses a polycarbonate copolymer obtained by interfacial polycondensation of bisphenol A and 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)bisphenol (bisphenol TMC). The Vicat softening point of the copolymer is effectively increased with the addition of bisphenol TMC. However, the monomer bisphenol TMC is expensive and accounts for up to 50% of the copolymer backbone, resulting in high preparation costs and making it unsuitable for industrial production. Chinese patent CN115286780B discloses a polycarbonate using a dihydroxy compound containing a pyrimidine structure as a copolymer unit. Compared with bisphenol A-type polycarbonate, its Vicat softening point is effectively increased. However, the preparation process uses a metal-containing catalyst, and the dihydroxy compound used has a complex structure and cumbersome synthesis steps, making large-scale production impossible. Chinese patent CN115322356B describes a high-temperature resistant and chemically resistant copolycarbonate obtained using a bisphenol monomer with trifluoromethyl side groups as the comonomer. Its glass transition temperature is increased from 145℃ to 219℃, but its elongation at break is around 100%, indicating room for improvement in the polymer's mechanical properties. Chinese patent CN107573497B describes an isosorbide-based polycarbonate catalyzed by an ionic liquid. The polymer has a number-average molecular weight of 61.7 kDa and a high glass transition temperature of 174℃, but the patent does not mention the polymer's mechanical properties.

[0004] Therefore, developing a metal-free condensation polymerization catalyst capable of withstanding high temperatures to synthesize heat-resistant bisphenol A type copolycarbonate has significant academic and application value. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a method for preparing heat-resistant bisphenol A type copolycarbonate. The method utilizes a metal-free catalyst for melt polycondensation of the bisphenol A type copolycarbonate, achieving efficient polymerization and heat-resistant modification of the polycarbonate.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] One objective of this invention is to provide a method for preparing heat-resistant bisphenol A type copolycarbonate, comprising the following steps: using bisphenol A and diester as monomers, using aromatic structures as copolymerization units, using imidazole ionic liquids as catalysts, carrying out transesterification reactions under a protective atmosphere, and then carrying out polycondensation reactions under vacuum conditions to obtain heat-resistant bisphenol A type copolycarbonate; wherein the aromatic structure is an aromatic dicarboxylic acid, an aromatic dicarboxylic acid ester, or an aromatic dihydroxy compound.

[0008] This invention employs a one-pot method, adding all materials at once. The monomers, copolymer units, and catalyst are mixed and then subjected to transesterification under a protective gas atmosphere. After removing most alcohol / phenolic byproducts, polycondensation is carried out under vacuum conditions to further remove byproducts, ultimately yielding a copolymer carbonate.

[0009] Further, the carbonate diester is one or more of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, diphenyl carbonate, dimethyl carbonate, and dinaphthalene carbonate, preferably at least one of dimethyl carbonate, diethyl carbonate, and diphenyl carbonate.

[0010] Further, the aromatic dicarboxylic acid is one or more of terephthalic acid, isophthalic acid, phthalic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and 3,4'-biphenyldicarboxylic acid; preferably at least one of terephthalic acid, isophthalic acid, and phthalic acid.

[0011] Further, the aromatic diester is one or more of dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate, diethyl terephthalate, diethyl isophthalate, diethyl phthalate, diphenyl terephthalate, diphenyl isophthalate, diphenyl phthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl 1,5-naphthalenedicarboxylate, dimethyl 2,7-naphthalenedicarboxylate, dimethyl 4,4'-biphenylenedicarboxylate, and dimethyl 3,4'-biphenylenedicarboxylate; preferably at least one of dimethyl terephthalate, dimethyl isophthalate, diethyl terephthalate, diethyl isophthalate, diphenyl terephthalate, and diphenyl isophthalate.

[0012] Further, the aromatic dihydroxy compound is one or more selected from 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 4,4'-dihydroxydiphenylmethane, 1,1'-bis(4-hydroxyphenyl)cyclohexane, 9,9-bis(4-hydroxyphenyl)fluorene (bisphenol fluorene), 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol, hydroquinone, and 3,3-bis(4-hydroxyphenyl)-3H-isobenzofuranone (phenolphthalein). Preferably, at least one of bisphenol fluorene and phenolphthalein is selected.

[0013] Furthermore, the structural formula of the imidazole ionic liquid is shown in formula (Ⅰ):

[0014]

[0015] (I)

[0016] Among them, R1, R2, and R3 are independently selected from hydrogen atoms, C atoms, and C atoms. n H 2n+1 C n H 2n and C n H 2n One of Z, where Z is -OH, -COOH, -NH2, or a halogen; n takes the value of an integer from 1 to 10; X ⊖ The anions are lactate, acetate, hexafluorophosphate, tetrafluoroborate, trifluoromethanesulfonate, nitrate, hydroxide, and F. - Cl - or Br - The imidazole-based ionic liquid catalyst is preferably 1-butyl-3-methylimidazolium lactate or 1-butyl-3-methylimidazolium acetate.

[0017] Furthermore, the total amount of hydroxyl groups in the monomers and copolymers is less than the total amount of ester and carboxyl groups. The preferred molar ratio of the total amount of hydroxyl groups to the total amount of ester and carboxyl groups in the monomers and copolymers is 1:(1-2).

[0018] Furthermore, the molar ratio of the catalyst to bisphenol A is 1:(10000-1000000).

[0019] Furthermore, the specific operation of the transesterification reaction is as follows: under a protective atmosphere, the reaction is carried out at 160-280℃ for 1-24 hours, and the protective atmosphere is nitrogen, helium or argon; preferably, the reaction is carried out at 200-260℃ for 2-12 hours.

[0020] The specific operation of the polycondensation reaction is as follows: under vacuum conditions, the reaction is carried out at 240-360℃ for 0.5-12 hours, with a vacuum degree of 10-500 Pa. Preferably, the reaction is carried out at 260-320℃ for 1-6 hours.

[0021] A second objective of this invention is to provide a heat-resistant bisphenol A type copolycarbonate, which is prepared using the above-described method. The heat-resistant bisphenol A type copolycarbonate has one of the following structures:

[0022] and Wherein, A and A' represent specific aromatic structures.

[0023] A third objective of this invention is to provide an application of heat-resistant bisphenol A type copolycarbonate in the preparation of polymer blends, polymer alloys, films, fibers, sheets and optical products.

[0024] The fourth objective of this invention is to provide an application of heat-resistant bisphenol A type copolycarbonate in the fields of new energy, electronic and electrical equipment, automotive parts, medical sterilization devices, or industrial equipment.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] The preparation method provided by this invention is simple in process, uses readily available raw materials, and avoids the use of toxic solvents. The properties of the copolymerized carbonate can be controlled by adjusting the type and proportion of added copolymer units, achieving an increase in glass transition temperature while retaining the mechanical and optical properties of bisphenol A type polycarbonate. The prepared copolymerized carbonate can be used to prepare polymer blends, polymer alloys, films, fibers, sheets, and optical products. Furthermore, it can be applied in new energy fields, electronic and electrical equipment, automotive parts, medical sterilization devices, and industrial equipment. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 The heat-resistant bisphenol A type copolycarbonate prepared in Example 1 1 H-NMR spectrum;

[0029] Figure 2 The tensile curve of the heat-resistant bisphenol A type copolycarbonate prepared in Example 1 is shown.

[0030] Figure 3 The tensile curve of the heat-resistant bisphenol A type copolycarbonate prepared in Example 3 is shown.

[0031] Figure 4 The heat-resistant bisphenol A type copolycarbonate prepared in Example 5 1H-NMR spectrum;

[0032] Figure 5 The tensile curve of the heat-resistant bisphenol A type copolycarbonate prepared in Example 6 is shown.

[0033] Figure 6 The tensile curve of the heat-resistant bisphenol A type copolycarbonate prepared in Example 7 is shown.

[0034] Figure 7 The heat-resistant bisphenol A type copolycarbonate prepared in Example 8 1 H-NMR spectrum;

[0035] Figure 8 The tensile curve of the heat-resistant bisphenol A type copolycarbonate prepared in Example 8 is shown.

[0036] Figure 9 The heat-resistant bisphenol A type copolycarbonate prepared in Example 10 1 H-NMR spectrum;

[0037] Figure 10 The tensile curve of the heat-resistant bisphenol A type copolycarbonate prepared in Example 10 is shown.

[0038] Figure 11 The bisphenol A type polycarbonate prepared in Comparative Example 1 1 H-NMR spectrum;

[0039] Figure 12 The tensile curve of the bisphenol A type copolycarbonate prepared in Comparative Example 1 is shown.

[0040] Figure 13 The stretching curve of the isosorbide-based polycarbonate prepared in Comparative Example 2 is shown.

[0041] Figure 14 The image shows the tensile curve of the bisphenol A terephthalic acid copolycarbonate prepared in Comparative Example 3. Detailed Implementation

[0042] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0043] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0044] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0045] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0046] The terms “comprising,” “including,” “having,” “containing,” etc., used in this invention are all open-ended terms, meaning that they include but are not limited to.

[0047] This invention provides a method for preparing heat-resistant bisphenol A type copolycarbonate, comprising the following steps: using bisphenol A and diester as monomers, using aromatic structures as copolymerization units (exemplarily, aromatic diesters or aromatic dihydroxy compounds can be selected), using imidazole ionic liquids as catalysts, carrying out transesterification reaction under a protective atmosphere, and then carrying out polycondensation reaction under vacuum conditions to obtain heat-resistant bisphenol A type copolycarbonate;

[0048] The aromatic structure is an aromatic dicarboxylic acid, an aromatic dicarboxylic acid ester, or an aromatic dihydroxy compound. Exemplarily, in the following preferred embodiments of the present invention, an aromatic dicarboxylic acid ester or an aromatic dihydroxy compound is selected as the copolymer unit.

[0049] In some optional embodiments of the present invention, the carbonate diester is one or more selected from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, diphenyl carbonate, xylene carbonate, and dinaphthalene carbonate, preferably at least one selected from dimethyl carbonate, diethyl carbonate, and diphenyl carbonate. Exemplarily, in the following preferred embodiments of the present invention, the carbonate diester is selected from diphenyl carbonate.

[0050] In some optional embodiments of the present invention, the aromatic dicarboxylic acid is one or more of terephthalic acid, isophthalic acid, phthalic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and 3,4'-biphenyldicarboxylic acid.

[0051] In some optional embodiments of the present invention, the aromatic dicarboxylic acid ester is one or more selected from dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate, diethyl terephthalate, diethyl isophthalate, diethyl phthalate, diphenyl terephthalate, diphenyl isophthalate, diphenyl phthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl 1,5-naphthalenedicarboxylate, dimethyl 2,7-naphthalenedicarboxylate, dimethyl 4,4'-biphenylenedicarboxylate, and dimethyl 3,4'-biphenylenedicarboxylate; exemplaryly, in the following preferred embodiments of the present invention, the aromatic dicarboxylic acid is diphenyl terephthalate or diphenyl isophthalate.

[0052] In some optional embodiments of the present invention, the aromatic dihydroxy compound is one or more selected from 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 4,4'-dihydroxydiphenylmethane, 1,1'-bis(4-hydroxyphenyl)cyclohexane, 9,9-bis(4-hydroxyphenyl)fluorene (bisphenol fluorene), 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol, hydroquinone, and 3,3-bis(4-hydroxyphenyl)-3H-isobenzofuranone (phenolphthalein). Exemplarily, in the following preferred embodiments of the present invention, the aromatic dihydroxy compound is bisphenol fluorene or phenolphthalein.

[0053] In some optional embodiments of the present invention, the structural formula of the imidazole ionic liquid is shown in formula (Ⅰ):

[0054]

[0055] (I)

[0056] Among them, R1, R2, and R3 are independently selected from hydrogen atoms, C atoms, and C atoms.n H 2n+1 C n H 2n and C n H 2n One of Z, where Z is -OH, -COOH, -NH2, or a halogen; n takes the value of an integer from 1 to 10; X ⊖ The anions are lactate, acetate, hexafluorophosphate, tetrafluoroborate, trifluoromethanesulfonate, nitrate, hydroxide, and F. - Cl - or Br - For example, in the following preferred embodiments of the present invention, the imidazole ionic liquid catalyst is preferably 1-butyl-3-methylimidazolium lactate, 1-butyl-3-methylimidazolium hexafluorophosphate, or 1-butyl-3-methylimidazolium acetate.

[0057] In some optional embodiments of the present invention, the total amount of hydroxyl groups in the monomers and copolymers is less than the total amount of ester and carboxyl groups. The molar ratio of the total amount of hydroxyl groups to the total amount of ester and carboxyl groups in the monomers and copolymers is 1:(1-2). Exemplarily, in the following preferred embodiments of the present invention, the molar ratio of the total amount of hydroxyl groups to the total amount of ester and carboxyl groups in the monomers and copolymers is 1:1.06.

[0058] In some optional embodiments of the present invention, the molar ratio of the catalyst to bisphenol A is 1:(10000-1000000). Exemplarily, in the following preferred embodiments of the present invention, the molar ratio of the catalyst to bisphenol A is 1:10000, 1:100000, or 1:1000000.

[0059] In some optional embodiments of the present invention, the transesterification reaction is specifically operated as follows: under a protective atmosphere, the reaction is carried out at 160-280°C for 1-24 hours, and the protective atmosphere is nitrogen, helium or argon; exemplaryly, in the following preferred embodiments of the present invention, the temperature of the transesterification reaction is 240°C or 260°C, and the reaction time is 3 hours or 4 hours.

[0060] In some optional embodiments of the present invention, the specific operation of the polycondensation reaction is as follows: under vacuum conditions, the reaction is carried out at 240-360°C for 0.5-12 hours, with a vacuum degree of 10-500 Pa. Exemplarily, in the following preferred embodiments of the present invention, the temperature of the polycondensation reaction is 280°C, and the reaction time is 1.5 hours.

[0061] A heat-resistant bisphenol A type copolycarbonate can be prepared using the above preparation method, which has one of the following structures:

[0062] and Wherein, A and A' represent specific aromatic structures. The aromatic structure is an aromatic dicarboxylic acid, an aromatic dicarboxylic acid ester, or an aromatic dihydroxy compound.

[0063] The heat-resistant bisphenol A type copolycarbonate can be used in materials for preparing polymer blends, polymer alloys, films, fibers, sheets and optical products.

[0064] The heat-resistant bisphenol A type copolycarbonate can be used in new energy fields, electronic and electrical equipment, automotive parts, medical sterilization devices, or industrial equipment.

[0065] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0066] All raw materials used in this invention were purchased from the market.

[0067] The technical solution of the present invention will be further illustrated by the following embodiments.

[0068] The present invention conducted relevant tests on the obtained polymer. The microstructure of the polymer was determined by nuclear magnetic resonance spectroscopy, the molecular weight and molecular weight distribution index were determined by gel permeation chromatography, and the glass transition temperature of the polymer was characterized by differential scanning calorimetry. The polymer... 1 ¹H-NMR was performed using a Bruker-400 NMR spectrometer at 25 °C, with TMS as the internal standard and deuterated chloroform as the solvent. Gel permeation chromatography was performed using a Waters gel permeation chromatograph. Tetrahydrofuran (THF) was used as the solvent (with 0.05 wt% 2,6-di-tert-butyl-4-methylphenol added as an antioxidant). The test temperature was 40 °C, and the flow rate was 1.0 mL / min. PLEasiCalPS-1 was used as the standard. DSC analysis of the sample was performed using a TA Instruments Q2000. 5 mg of sample was weighed into an aluminum crucible, and under a nitrogen atmosphere, the temperature was increased from room temperature to 200 °C at a rate of 10 °C / min, held for 10 min, then decreased to -20 °C at the same rate, held for 10 min, and then increased to 200 °C again at the same rate. After preparing a polymer solution of 100 mg / mL, the polymer film was laid and dried in a vacuum oven at 120 °C for 10 h. The polymer was then subjected to tensile testing using an Instron 5969 electronic universal testing machine at a tensile rate of 10 mm / min.

[0069] Example 1

[0070] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 32.45 g (0.1515 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of diphenyl terephthalate are weighed and added to a 100 mL reactor. 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 3 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, and the molecular weight was determined to be 32.9 kDa, with a glass transition temperature of 147.5 °C. 1 The polymer structure was characterized by H-NMR, and the results are as follows: Figure 1 As shown. Tensile property tests show that the tensile strength is 72.0 MPa and the elongation at break is 141% (see...). Figure 2 ).

[0071] Example 2

[0072] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 33.10 g (0.1545 mol) of diphenyl carbonate, and 1.43 g (0.0045 mol) of diphenyl terephthalate are weighed and added to a 100 mL reactor. 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature is gradually increased to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature in the reactor is increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, and the molecular weight was found to be 31.6 kDa, with a glass transition temperature of 146.6℃. Tensile property tests showed a tensile strength of 52.3 MPa and an elongation at break of 118%.

[0073] Example 3

[0074] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 30.85 g (0.144 mol) of diphenyl carbonate, and 4.78 g (0.015 mol) of diphenyl terephthalate are weighed and added to a 100 mL reactor. 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 2 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, and the molecular weight was found to be 31.8 kDa, with a glass transition temperature of 150.4℃. Tensile property tests showed a tensile strength of 55.5 MPa and an elongation at break of 123% (see [reference]). Figure 3 ).

[0075] Example 4

[0076] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 32.45 g (0.1515 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of diphenyl terephthalate are weighed and added to a 100 mL reactor. 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature is gradually increased to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature in the reactor is increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, and the molecular weight was found to be 30.8 kDa, with a glass transition temperature of 147.0℃. Tensile property tests showed a tensile strength of 54.8 MPa and an elongation at break of 125%.

[0077] Example 5

[0078] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 33.10 g (0.1545 mol) of diphenyl carbonate, and 1.43 g (0.0045 mol) of diphenyl isophthalate are weighed and added to a 100 mL reactor. 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature is gradually increased to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature in the reactor is increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 27.8 kDa and a glass transition temperature of 143.8 °C. 1 The polymer structure was characterized by H-NMR, and the results are as follows: Figure 4 As shown in the figure. Tensile property tests reveal a tensile strength of 52.7 MPa and an elongation at break of 116%.

[0079] Example 6

[0080] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 32.45 g (0.1515 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of diphenyl isophthalate are weighed and added to a 100 mL reactor. 0.342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:100000). The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 29.7 kDa and a glass transition temperature of 145.7 °C. Tensile property tests showed a tensile strength of 56.3 MPa and an elongation at break of 129% (see [reference]). Figure 5 ).

[0081] Example 7

[0082] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 30.85 g (0.144 mol) of diphenyl carbonate, and 4.78 g (0.015 mol) of diphenyl isophthalate are weighed and added to a 100 mL reactor. 3.42 mg of catalyst 1-butyl-3-methylimidazolium lactate (the molar ratio of catalyst to bisphenol A is 1:10000) is added. The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 26.6 kDa and a glass transition temperature of 148.8 °C. Tensile property tests showed a tensile strength of 63.1 MPa and an elongation at break of 140% (see [reference]). Figure 6 ).

[0083] Example 8

[0084] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 32.53 g (0.1425 mol) of bisphenol A, 34.06 g (0.159 mol) of diphenyl carbonate, and 2.63 g (0.0075 mol) of bisphenol fluorene are weighed and added to a 100 mL reactor. 3.42 mg of catalyst 1-butyl-3-methylimidazolium lactate (the molar ratio of catalyst to bisphenol A is 1:10000) is added. The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 3 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 28.1 kDa and a glass transition temperature of 150.2 °C. 1 The polymer structure was characterized by H-NMR, and the results are as follows: Figure 7 As shown. Tensile property tests show that the tensile strength is 64.1 MPa and the elongation at break is 98% (see...). Figure 8 ).

[0085] Example 9

[0086] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 32.53 g (0.1425 mol) of bisphenol A, 34.06 g (0.159 mol) of diphenyl carbonate, and 2.63 g (0.0075 mol) of bisphenol fluorene are weighed and added to a 100 mL reactor. 0.342 mg of catalyst 1-butyl-3-methylimidazolium lactate (the molar ratio of catalyst to bisphenol A is 1:100000) is added. The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, revealing a molecular weight of 18.8 kDa and a glass transition temperature of 136.8 °C. Tensile property tests showed a tensile strength of 43.8 MPa and an elongation at break of 62%.

[0087] Example 10

[0088] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 32.53 g (0.1425 mol) of bisphenol A, 34.06 g (0.159 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of phenolphthalein are weighed and added to a 100 mL reactor. 0.342 mg of 1-butyl-3-methylimidazolium lactate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:100000). The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 260 °C and reacted for 3 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 29.1 kDa and a glass transition temperature of 151.4 °C. 1 The polymer structure was characterized by H-NMR, and the results are as follows: Figure 9 As shown. Tensile property tests show that the tensile strength is 56.4 MPa and the elongation at break is 99% (see...). Figure 10 ).

[0089] Example 11

[0090] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 32.53 g (0.1425 mol) of bisphenol A, 34.06 g (0.159 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of phenolphthalein are weighed and added to a 100 mL reactor. 0.342 mg of 1-butyl-3-methylimidazolium lactate catalyst (the molar ratio of catalyst to bisphenol A is 1:100000) is added. The reactor is purged with nitrogen at least three times, and the temperature inside the reactor is gradually raised to 240 °C and reacted for 4 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature inside the reactor is raised to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, revealing a molecular weight of 22.0 kDa and a glass transition temperature of 133.5 °C. Tensile property tests showed a tensile strength of 47.7 MPa and an elongation at break of 66%.

[0091] Example 12

[0092] A method for preparing a heat-resistant bisphenol A type copolycarbonate includes the following steps: 34.24 g (0.15 mol) of bisphenol A, 32.45 g (0.1515 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of diphenyl terephthalate are weighed and added to a 100 mL reactor. 0.0426 mg of 1-butyl-3-methylimidazolium hexafluorophosphate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature is gradually increased to 240 °C and reacted for 3 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature in the reactor is increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, revealing a molecular weight of 23.8 kDa and a glass transition temperature of 136.3 °C. Tensile property tests showed a tensile strength of 58.0 MPa and an elongation at break of 126%.

[0093] Example 13

[0094] A method for preparing a heat-resistant bisphenol A type copolycarbonate comprises the following steps: 34.24 g (0.15 mol) of bisphenol A, 32.45 g (0.1515 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of diphenyl terephthalate are weighed and added to a 100 mL reactor. 0.0297 mg of 1-butyl-3-methylimidazolium acetate catalyst is added (the molar ratio of catalyst to bisphenol A is 1:1,000,000). The reactor is purged with nitrogen at least three times, and the temperature is gradually increased to 240 °C and reacted for 3 h under a nitrogen atmosphere. During the reaction, the byproduct phenol is collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system is reduced to 20 Pa, and the phenol in the system is gradually removed. At the same time, the temperature of the reactor is increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, revealing a molecular weight of 22.3 kDa and a glass transition temperature of 135.8 °C. Tensile property tests showed a tensile strength of 57.3 MPa and an elongation at break of 119%.

[0095] Example 14

[0096] Similar to Example 7, except that the amount of catalyst 1-butyl-3-methylimidazolium lactate added was 0.342 mg. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 21.8 kDa and a glass transition temperature of 135.6 °C. Tensile property tests showed a tensile strength of 51.3 MPa and an elongation at break of 122%.

[0097] Example 15

[0098] Similar to Example 2, except that the reaction was carried out at 240°C under a nitrogen atmosphere for 3 hours. The structure, thermal properties, and molecular weight of the resulting product were tested, yielding a molecular weight of 20.9 kDa and a glass transition temperature of 134.6°C. Tensile property tests showed a tensile strength of 48.2 MPa and an elongation at break of 92%.

[0099] Comparative Example 1

[0100] Similar to Example 1, except that no copolymerization unit was added. The specific steps are as follows: 34.24 g (0.15 mol) of bisphenol A and 34.06 g (0.159 mol) of diphenyl carbonate were weighed and added to a 100 mL reactor. 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst (the molar ratio of catalyst to bisphenol A was 1:1,000,000) was added. The reactor was purged with nitrogen at least three times, and the temperature was gradually increased to 240 °C and reacted for 3 hours under a nitrogen atmosphere. During the reaction, the byproduct phenol was collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system was reduced to 20 Pa, and the phenol was gradually removed from the system. Simultaneously, the temperature was increased to 280 °C and reacted for 1.5 hours. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 28.2 kDa and a glass transition temperature of 141.1 °C. 1 The polymer structure was characterized by H-NMR, and the results are as follows: Figure 11 As shown. Tensile property tests show that the tensile strength is 49.7 MPa and the elongation at break is 123% (see...). Figure 12 ).

[0101] Comparative Example 2

[0102] 21.92 g (0.15 mol) of isosorbide and 34.06 g (0.159 mol) of diphenyl carbonate were weighed and added to a 100 mL reactor. After preparing the catalyst dilution solution, 0.0342 mg of 1-butyl-3-methylimidazolium lactate catalyst (catalyst to isosorbide molar ratio of 1:1,000,000) was added. The reactor was purged at least three times with nitrogen. The reactor temperature was gradually increased to 240 °C and reacted under a nitrogen atmosphere for 3 h. During the reaction, the byproduct phenol was collected in a cold trap. After the prepolymerization stage, the reaction system pressure was reduced to 20 Pa, and the phenol was gradually removed from the system. Simultaneously, the reactor temperature was increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the obtained product were tested, yielding a molecular weight of 23.8 kDa and a glass transition temperature of 162.1 °C. The tensile properties test showed that the tensile strength was 54.9 MPa and the elongation at break was 58% (see [reference]). Figure 13 ).

[0103] Comparative Example 3

[0104] 34.24 g (0.15 mol) of bisphenol A, 32.45 g (0.1515 mol) of diphenyl carbonate, and 2.39 g (0.0075 mol) of diphenyl terephthalate were weighed and added to a 100 mL reactor. 0.006 mg of sodium hydroxide catalyst was added (the molar ratio of catalyst to bisphenol A was 1:1,000,000). The reactor was purged at least three times with nitrogen. The reactor temperature was gradually increased to 240 °C and reacted under a nitrogen atmosphere for 3 h. During the reaction, the byproduct phenol was collected in a cold trap. After the prepolymerization stage, the pressure of the reaction system was reduced to 20 Pa, and the phenol was gradually removed from the system. Simultaneously, the reactor temperature was increased to 280 °C and reacted for 1.5 h. The structure, thermal properties, and molecular weight of the resulting product were tested, yielding a molecular weight of 23.8 kDa and a glass transition temperature of 138.5 °C. Tensile property tests show that the tensile strength is 52.5 MPa and the elongation at break is 96% (see [reference]). Figure 14 ).

[0105] A comparison of Examples 1-4, 6-8, 10, and Comparative Example 1 reveals that the addition of copolymer units significantly increases the glass transition temperature of bisphenol A polycarbonate, achieving a tensile strength of 72.0 MPa and an elongation at break of 141%. A comparison between Example 1 and Comparative Example 2 shows that while isosorbide-based polycarbonate exhibits a high glass transition temperature, its actual mechanical properties are poor, with a low elongation at break, rendering it unsuitable for practical applications. A comparison between Example 1 and Comparative Example 3 reveals that the catalytic activity of traditional metal-containing catalysts, such as sodium hydroxide, is inferior to that of ionic liquid catalysts, and the resulting copolycarbonate exhibits lower molecular weight, glass transition temperature, tensile strength, and elongation at break compared to the copolycarbonate obtained in Example 1. Therefore, the copolycarbonate prepared by this method can achieve an increased glass transition temperature and improved mechanical properties by controlling the structure and dosage of the comonomers.

[0106] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a heat-resistant bisphenol A type copolycarbonate, characterized in that, Includes the following steps: Using bisphenol A and diester as monomers, aromatic structures as copolymerization units, and imidazole ionic liquids as catalysts, transesterification was carried out under a protective atmosphere, followed by polycondensation under vacuum conditions to obtain heat-resistant bisphenol A type copolycarbonate. The aromatic structure is an aromatic dicarboxylic acid, an aromatic dicarboxylic acid ester, or an aromatic dihydroxy compound.

2. The method for preparing heat-resistant bisphenol A type copolycarbonate according to claim 1, characterized in that, The carbonate diester is selected from one or more of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, diphenyl carbonate, dimethyl carbonate, and dinaphthalene carbonate.

3. The method for preparing heat-resistant bisphenol A type copolycarbonate according to claim 1, characterized in that, The aromatic dicarboxylic acid is selected from one or more of terephthalic acid, isophthalic acid, phthalic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and 3,4'-biphenyldicarboxylic acid; and / or, The aromatic diester is selected from one or more of dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate, diethyl terephthalate, diethyl isophthalate, diethyl phthalate, diphenyl terephthalate, diphenyl isophthalate, diphenyl phthalate, diphenyl phthalate, 2,6-naphthalenedicarboxylate, dimethyl 1,5-naphthalenedicarboxylate, dimethyl 2,7-naphthalenedicarboxylate, dimethyl 4,4'-biphenylenediate, and dimethyl 3,4'-biphenylenediate; and / or, The aromatic dihydroxy compound is selected from one or more of 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 4,4'-dihydroxydiphenylmethane, 1,1'-bis(4-hydroxyphenyl)cyclohexane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol, hydroquinone, and 3,3-bis(4-hydroxyphenyl)-3H-isobenzofuranone.

4. The method for preparing heat-resistant bisphenol A type copolycarbonate according to claim 1, characterized in that, The structural formula of the imidazole ionic liquid is shown in formula (Ⅰ): （Ⅰ） Among them, R1, R2, and R3 are independently selected from hydrogen atoms, C atoms, and C atoms. n H 2n+1 C n H 2n and C n H 2n One of Z, where Z is -OH, -COOH, -NH2, or a halogen; n takes the value of an integer from 1 to 10; X ⊖ The anions are lactate, acetate, hexafluorophosphate, tetrafluoroborate, trifluoromethanesulfonate, nitrate, hydroxide, and F. - Cl - or Br - .

5. The method for preparing heat-resistant bisphenol A type copolycarbonate according to claim 1, characterized in that, The total amount of hydroxyl groups in the monomers and copolymers is less than the total amount of ester and carboxyl groups.

6. The method for preparing heat-resistant bisphenol A type copolycarbonate according to claim 1, characterized in that, The molar ratio of the catalyst to bisphenol A is 1:(10000-1000000).

7. The method for preparing heat-resistant bisphenol A type copolycarbonate according to claim 1, characterized in that, The specific operation of the transesterification reaction is as follows: under a protective atmosphere, the reaction is carried out at 160-280℃ for 1-24 hours, and the protective gas is nitrogen, helium or argon. The specific operation of the polycondensation reaction is as follows: under vacuum conditions, the reaction is carried out at 240-360℃ for 0.5-12 hours, with a vacuum degree of 10-500 Pa.

8. A heat-resistant bisphenol A type copolycarbonate, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. The use of the heat-resistant bisphenol A type copolycarbonate as described in claim 8 in the preparation of polymer blends, polymer alloys, films, fibers, sheets and optical products.

10. The application of the heat-resistant bisphenol A type copolycarbonate as described in claim 8 in the fields of new energy, electronic and electrical equipment, automotive parts, medical sterilization devices or industrial equipment.

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