Polycarbonates of isosorbide with controllable glass transition temperature and methods for their preparation

Abstract

This invention discloses an isosorbide-based polycarbonate with a controllable glass transition temperature and its preparation method. The preparation method includes: subjecting isosorbide, hydrogenated bisphenol A, and carbonate diester to at least a transesterification reaction and a polycondensation reaction in the presence of a catalyst to obtain the isosorbide-based polycarbonate with a controllable glass transition temperature. This invention can improve the toughness and processability of isosorbide-based polycarbonate, enhance its UV resistance, and give it a controllable glass transition temperature.

Description

Technical Field

[0001] This invention relates to an isosorbide-based polycarbonate with controllable glass transition temperature and its preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] Polycarbonate (PC) is a high-molecular-weight polymer containing carbonate bonds in its molecular chain. It possesses excellent physical properties and chemical stability, and is widely used in industry and daily life. It is the only engineering plastic with high transparency, and due to its unique structure, it has gradually become the fastest-growing and most promising general-purpose engineering plastic. Bisphenol A-type polycarbonate (BPA-PC), as a representative of polycarbonate, has excellent comprehensive properties, including outstanding light transmittance, good impact toughness, and weather resistance, thus finding wide application in aerospace, medical devices, and the electronics industry. However, the petroleum-based monomer bisphenol A (BPA) is a harmful substance with endocrine toxicity. Studies have found that BPA has chronic toxicity and estrogenic effects, which may harm human health. Because of its harmfulness to humans, BPA has significantly limited the use of BPA-PC in food packaging and medical devices, and the increasingly scarce petroleum resources further restrict its development potential. Therefore, finding a green, safe, and widely available bio-based monomer is urgently needed.

[0003] Isosorbide (ISB) is a bio-based monomer derived from cellulose. ISB has attracted significant attention due to its unique furan ring structure and non-toxicity. Products derived from ISB exhibit excellent physical properties and chemical stability. Polycarbonates synthesized from ISB show superior overall performance, are more environmentally friendly, and are non-toxic and harmless to human health. The use of isosorbide to replace the petroleum-based monomer BPA in the preparation of polycarbonates has become a hot research topic in the polycarbonate field.

[0004] The phosgene process is the most widely used and earliest method for large-scale industrial production of polycarbonate. However, this process involves a large number of toxic reagents, posing serious risks to human health and the environment. In recent years, the synthesis of isosorbide-based polycarbonate (PIC) using diphenyl carbonate (DPC) and ISB as raw materials via melt transesterification polycondensation has attracted significant attention. The main process involves applying high temperature and negative pressure to the raw materials in a closed reaction vessel, causing them to undergo transesterification and polycondensation reactions in a molten state, ultimately yielding the product. Melt transesterification polycondensation is currently the most feasible and green chemistry-compliant method for PIC preparation.

[0005] However, the rigid bisfuran ring structure of ISB results in high rigidity and poor toughness in PIC synthesized by melt transesterification polycondensation, making it difficult to form high molecular weight polymers. Its tensile strength fails to meet engineering plastic standards, and its high melt viscosity hinders product processing and shaping. Therefore, modifying PIC to improve its toughness and processing properties is one of the problems to be solved in this field. Furthermore, controlling the glass transition temperature of polycarbonate to broaden its application scenarios is also an issue to be addressed in this field. Summary of the Invention

[0006] To address at least one of the aforementioned technical problems, the present invention aims to provide an isosorbide-based polycarbonate with a controllable glass transition temperature and a method for preparing the same. The present invention improves the toughness and processing properties of isosorbide-based polycarbonate, enhances its UV resistance, and provides a controllable glass transition temperature.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing isosorbide-based polycarbonate with controllable glass transition temperature, comprising the following steps:

[0008] The isosorbide dicarbonate, isosorbide (ISB), and hydrogenated bisphenol A (HBPA) are subjected to at least transesterification and polycondensation reactions in the presence of a catalyst to obtain the isosorbide-type polycarbonate with controllable glass transition temperature.

[0009] The amount of hydrogenated bisphenol A used is 15-35% of the total molar amount of isosorbide and hydrogenated bisphenol A, and the amount of isosorbide used is 65-85% of the total molar amount of isosorbide and hydrogenated bisphenol A; the molar ratio of the carbonate diester to the total amount of isosorbide and hydrogenated bisphenol A is (1.01-1.05):1.

[0010] According to a specific embodiment of the present invention, preferably, the amount of hydrogenated bisphenol A is 25-30% of the total molar amount of isosorbide and hydrogenated bisphenol A, and the amount of isosorbide is 70-75% of the total molar amount of isosorbide and hydrogenated bisphenol A.

[0011] According to a specific embodiment of the present invention, preferably, the diester includes one or more of dimethyl carbonate, diphenyl carbonate (DPC), diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, and dioctyl carbonate. More preferably, the diester is diphenyl carbonate.

[0012] According to a specific embodiment of the present invention, preferably, the catalyst includes one or more of the following: sodium hydroxide, cesium carbonate, lithium acetylacetonate, lithium chloride, tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, methyl titanate, trimethyl phosphate, triethyl phosphate, and triphenyl phosphate.

[0013] According to a specific embodiment of the present invention, preferably, the amount of catalyst used is 0.001 to 1 ppm of the mass of the diester.

[0014] According to a specific embodiment of the present invention, preferably, the preparation method further includes raw material slurry preparation before the transesterification reaction and polycondensation reaction. The raw material slurry preparation includes: mixing diester, isosorbide, and hydrogenated bisphenol A in a protective gas atmosphere, followed by slurry preparation at 100–150°C for 0.5–1 h, and then adding a catalyst. More preferably, the protective gas includes gases that do not react with the system, such as nitrogen (N2) and / or argon (Ar).

[0015] According to a specific embodiment of the present invention, preferably, the conditions for the transesterification reaction include: a reaction temperature of 150–200°C, a pressure of 30–60 kPa, and a time of 1–2 h.

[0016] According to a specific embodiment of the present invention, preferably, the conditions for the polycondensation reaction include: a reaction temperature of 200-250°C, a pressure of 100-300 Pa, and a time of 1-3 h.

[0017] According to a specific embodiment of the present invention, preferably, the preparation method further includes, during the transesterification reaction and / or the polycondensation reaction, removing the alcohols and / or phenols (byproducts) generated in the reaction from the reaction system.

[0018] The second aspect of the present invention provides an isosorbide-type polycarbonate with a controllable glass transition temperature, which is prepared by the above-described method for preparing isosorbide-type polycarbonate with a controllable glass transition temperature.

[0019] According to a specific embodiment of the present invention, preferably, the isosorbide-type polycarbonate with controllable glass transition temperature has the structural formula shown in Formula I:

[0020]

[0021] In Formula I, n = 25 to 100. More preferably, n = 60 to 100.

[0022] According to a specific embodiment of the present invention, preferably, the number average molecular weight of the isosorbide-type polycarbonate with controllable glass transition temperature is 10,000 to 40,000 g / mol, more preferably 20,000 to 40,000 g / mol.

[0023] According to a specific embodiment of the present invention, preferably, the glass transition temperature of the isosorbide-type polycarbonate with controllable glass transition temperature is 80-135°C.

[0024] According to a specific embodiment of the present invention, preferably, the melt flow rate of the isosorbide-type polycarbonate with controllable glass transition temperature is 5 to 70 g / 10 min.

[0025] According to a specific embodiment of the present invention, preferably, the isosorbide-type polycarbonate with controllable glass transition temperature has an elongation at break of 10-30% and a tensile strength of 58-75 MPa.

[0026] According to a specific embodiment of the present invention, preferably, the transmittance of the isosorbide-type polycarbonate with controllable glass transition temperature is 85-92%, more preferably 88-92%.

[0027] The present invention has at least the following beneficial effects:

[0028] This invention prepares isosorbide-based polycarbonate with a controllable glass transition temperature via melt transesterification polycondensation using diester, ISB, and HBPA as raw materials. This invention improves the toughness of isosorbide-based polycarbonate, giving it better mechanical properties. Furthermore, this invention addresses the defects caused by the unique rigid bifuran ring structure of isosorbide, such as high melt viscosity, poor processability, and high brittleness. The isosorbide-based polycarbonate of this invention has better flowability, making it more suitable for practical processing applications. Moreover, this invention enhances the UV resistance of isosorbide-based polycarbonate. Simultaneously, the isosorbide-based polycarbonate of this invention also exhibits good optical properties (transmittance) and thermal stability. Furthermore, the isosorbide-based polycarbonate of this invention has a controllable glass transition temperature, which can be adjusted according to the requirements of the application scenario, thus having a wider range of applications. In addition, the preparation method of this invention has a simple process flow, avoids the use of toxic raw materials and endocrine-toxic monomers, and the catalyst does not require recovery. In addition, the isosorbide-based polycarbonate of the present invention can replace the traditional aromatic bisphenol A type polycarbonate, which can reduce dependence on petroleum-based monomers and reduce the consumption of non-renewable resources such as petroleum. Attached Figure Description

[0029] Figure 1 The FT-IR curves of PIHC-2 and PIHC-4 prepared in Examples 2 and 4 of this invention are shown. Detailed Implementation

[0030] To provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the present invention will now be described in detail below, but this should not be construed as limiting the scope of the invention.

[0031] It should be noted that, unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0033] It should be understood that the terms “comprising,” “including,” and / or “containing” as used herein specify the presence of the stated features, integers, steps, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof.

[0034] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0035] Example 1

[0036] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 15% of the total molar amount of HBPA and ISB, and the amount of ISB was 85% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, sodium hydroxide catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0037] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0038] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-1.

[0039] Example 2

[0040] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 20% of the total molar amount of HBPA and ISB, and the amount of ISB was 80% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, the catalyst cesium carbonate was added, and its amount was 0.1ppm of the mass of DPC.

[0041] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0042] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-2.

[0043] Example 3

[0044] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 25% of the total molar amount of HBPA and ISB, and the amount of ISB was 75% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, lithium acetylacetone catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0045] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0046] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-3.

[0047] Example 4

[0048] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 30% of the total molar amount of HBPA and ISB, and the amount of ISB was 70% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, lithium chloride catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0049] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0050] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-4.

[0051] Example 5

[0052] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 35% of the total molar amount of HBPA and ISB, and the amount of ISB was 65% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, tetrabutyl titanate catalyst was added, with a dosage of 0.1ppm of DPC mass.

[0053] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0054] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-5.

[0055] Example 6

[0056] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.03:1. The amount of HBPA was 15% of the total molar amount of HBPA and ISB, and the amount of ISB was 85% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 150℃ for raw material pulping and maintained for about 1 hour. Then, tetraethyl titanate catalyst was added, with a dosage of 1 ppm of the mass of DPC.

[0057] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 200℃, the vacuum pump is turned on to evacuate the reactor to 30kPa, and the reaction is carried out for 2 hours. During the transesterification reaction, the phenol generated in the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0058] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 250℃ and reduce the pressure of the reactor to 100Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-6.

[0059] Example 7

[0060] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.05:1. The amount of HBPA was 15% of the total molar amount of HBPA and ISB, and the amount of ISB was 85% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 100℃ for raw material pulping and maintained for about 0.5h. Then, the catalyst methyl titanate was added, and its amount was 0.001ppm of the mass of DPC.

[0061] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 150℃, the vacuum pump is turned on to evacuate the reactor to 60kPa, and the reaction is carried out for 1 hour. During the transesterification reaction, the phenol generated in the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0062] (3) Polycondensation reaction stage: Raise the temperature to 200℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 220℃ and reduce the pressure of the reactor to 100Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-7.

[0063] Example 8

[0064] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. Dimethyl carbonate (DMC), HBPA, and ISB were added in sequence. The molar ratio of DMC to the total amount of HBPA and ISB (i.e., DMC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 15% of the total molar amount of HBPA and ISB, and the amount of ISB was 85% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, the catalyst trimethyl phosphate was added, and its amount was 0.1ppm of the mass of DMC.

[0065] (2) Transesterification reaction stage: After mixing each monomer raw material with the catalyst evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the methanol generated in the reaction is extracted from the reaction system and collected in the methanol storage tank.

[0066] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 100Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-8.

[0067] Comparative Example 1

[0068] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC and ISB were added in sequence, with a molar ratio of DPC to ISB of 1.01:1. After the addition was completed, the reactor was closed, and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, sodium hydroxide catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0069] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0070] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIC-1.

[0071] Comparative Example 2

[0072] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC and HBPA were added in sequence, with a molar ratio of DPC to HBPA of 1.01:1. After the addition was completed, the reactor was closed, and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, sodium hydroxide catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0073] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0074] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PHC-1.

[0075] Comparative Example 3

[0076] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 5% of the total molar amount of HBPA and ISB, and the amount of ISB was 95% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, sodium hydroxide catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0077] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0078] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-D1.

[0079] Comparative Example 4

[0080] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, HBPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of HBPA and ISB (i.e., DPC:(HBPA+ISB)) was 1.01:1. The amount of HBPA was 50% of the total molar amount of HBPA and ISB, and the amount of ISB was 50% of the total molar amount of HBPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, sodium hydroxide catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0081] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0082] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PIHC-D2.

[0083] Comparative Example 5

[0084] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, BPA (bisphenol A), and ISB were added in sequence. The molar ratio of DPC to the total amount of BPA and ISB (i.e., DPC:(BPA+ISB)) was 1.01:1. The amount of BPA was 15% of the total molar amount of BPA and ISB, and the amount of ISB was 85% of the total molar amount of BPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, sodium hydroxide catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0085] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0086] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PC-1.

[0087] Comparative Example 6

[0088] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, BPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of BPA and ISB (i.e., DPC:(BPA+ISB)) was 1.01:1. The amount of BPA was 20% of the total molar amount of BPA and ISB, and the amount of ISB was 80% of the total molar amount of BPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, the catalyst cesium carbonate was added, and its amount was 0.1ppm of the mass of DPC.

[0089] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0090] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PC-2.

[0091] Comparative Example 7

[0092] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, BPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of BPA and ISB (i.e., DPC:(BPA+ISB)) was 1.01:1. The amount of BPA was 25% of the total molar amount of BPA and ISB, and the amount of ISB was 75% of the total molar amount of BPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, lithium acetylacetone catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0093] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0094] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PC-3.

[0095] Comparative Example 8

[0096] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, BPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of BPA and ISB (i.e., DPC:(BPA+ISB)) was 1.01:1. The amount of BPA was 30% of the total molar amount of BPA and ISB, and the amount of ISB was 70% of the total molar amount of BPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, lithium chloride catalyst was added, with a dosage of 0.1ppm of the mass of DPC.

[0097] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0098] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PC-4.

[0099] Comparative Example 9

[0100] (1) Raw material pulping stage: A 5L reactor was used, equipped with an N2 inlet, raw material inlet, by-product outlet, mechanical stirring device, temperature and pressure monitoring probe, heating device, vacuum pump, etc. Before the experiment, the empty reactor was checked for leaks, and the vacuum was evacuated to 200Pa and maintained for a period of time. When the leakage was less than 3%, the experiment began. DPC, BPA, and ISB were added in sequence. The molar ratio of DPC to the total amount of BPA and ISB (i.e., DPC:(BPA+ISB)) was 1.01:1. The amount of BPA was 35% of the total molar amount of BPA and ISB, and the amount of ISB was 65% of the total molar amount of BPA and ISB. After the addition was completed, the reactor was closed and N2 replacement protection was performed. The heating temperature was set to 140℃ for raw material pulping and maintained for about 0.5h. Then, tetrabutyl titanate catalyst was added, with a dosage of 0.1ppm of DPC mass.

[0101] (2) Transesterification reaction stage: After the monomer raw materials and catalyst are mixed evenly, the heating temperature is set to 180℃, the vacuum pump is turned on to evacuate the reactor to 50kPa, and the reaction is carried out for 1.5h. During the transesterification reaction, the phenol generated by the reaction is extracted from the reaction system and collected in the phenol storage tank. In order to prevent phenol from condensing, the heat preservation circulating water of the phenol storage tank is turned on and the circulating water temperature is set to 45~50℃.

[0102] (3) Polycondensation reaction stage: Raise the temperature to 220℃, and at the same time control the vacuum pump to reduce the pressure of the reactor by 10kPa every 20min until it is reduced to 300Pa. Then raise the temperature to 240℃ and reduce the pressure of the reactor to 200Pa. Continue the reaction for 1h. When the reaction is over, take out the product and record it as PC-5.

[0103] Test case

[0104] Infrared spectroscopy was performed on PIHC-2 and PIHC-4 prepared in Examples 2 and 4 respectively using a Fourier transform infrared spectrometer. The test conditions included a scanning range of 4000-400 cm⁻¹. -1 The number of scans was 32, and the resolution was 4cm. -1 Background acquisition mode. Preparation method of test sample: The product prepared in the example is mixed with potassium bromide powder at a mass ratio of 1:100, and then compressed into tablets to obtain the test sample.

[0105] The FT-IR curves obtained from the test are as follows: Figure 1 As shown. By Figure 1 It can be seen that 1735cm -1 The absorption peak at 1236 cm⁻¹ is the carbonyl (C=O) vibration peak. -1 The nearby absorption peaks are ether bond (COC) vibration peaks, indicating that the polycarbonate copolymer target product was obtained in the embodiments of the present invention, and its structural formula is shown in Formula I:

[0106]

[0107] The number-average molecular weights of the polymer products prepared in each example and comparative example were determined using gel permeation chromatography (GPC), and the degree of polymerization n was calculated using the following formula: number-average molecular weight ÷ molecular weight of repeating unit. Test conditions included: an Agilent PLgel 5μm MIXED-D column, N,N-dimethylformamide as solvent, polystyrene as standard, a test temperature of 35℃, and a sample concentration of 1 mg / ml. The test results are shown in Table 1.

[0108] The polymer products prepared in the above examples and comparative examples were tested using the following methods, and the test results are shown in Tables 1, 2, 3, 4 and 5.

[0109] Melt flow rate: The test was conducted according to the description in GB / T 3682.1-2018. The sample particles were dried at 120℃ for 2-3 hours. Approximately 5.5g of sample was weighed for each measurement. The heating mantle temperature was set to 230℃ and the load was set to 2.16kg.

[0110] Elongation at break and tensile strength: Tensile strength and elongation at break were tested according to the description in GB / T 1040.1-2018 at a test rate of 50 mm / min. Dumbbell-shaped samples were used, and the sample size was 1A type as specified in GB / T 1040.2-2022.

[0111] Glass transition temperature: According to GB / T 11998-1989, after vacuum drying the sample particles at 110℃ for 4 hours, 3.0–5.0 mg of the dried sample was placed in a reference cell. Under a high-purity nitrogen atmosphere (50 mL / min), the temperature was increased from -20℃ to 200℃ at a rate of 10℃ / min, held for 1 minute, cooled to 0℃ at a rate of -20℃ / min, and finally heated to 200℃ at a rate of 10℃ / min. The second heating process was taken as the heating curve, and the T value at the inflection point could be obtained. g .

[0112] Light transmittance: Tested according to the specifications in GB / T 2410-2008. A circular piece with a diameter of 50 mm or a square piece of 50 mm × 50 mm was used for the test.

[0113] UV resistance test: The test was conducted according to the specifications in GB / T 16422.3-2022. A 50mm diameter disc was used for the test.

[0114] Table 1. Results of number-average molecular weight and melt flow rate tests

[0115]

[0116]

[0117] Table 2 Mechanical property test results

[0118]

[0119] Table 3. Test results of glass transition temperature

[0120]

[0121]

[0122] Table 4. Light transmittance test results

[0123] polymer HBPA content (%) BPA content (%) Light transmittance (%) PIHC-1 15 0 89.41 PIHC-2 20 0 89.91 PIHC-3 25 0 91.91 PIHC-4 30 0 91.05 PIHC-5 35 0 89.87 PIHC-6 15 0 89.88 PIHC-7 15 0 88.91 PIHC-8 15 0 88.65 PIC-1 0 0 90.55 PHC-1 100 0 90.47 PIHC-D1 5 0 89.94 PIHC-D2 50 0 90.27 PC-1 0 15 90.37 PC-2 0 20 91.75 PC-3 0 25 91.06 PC-4 0 30 89.88 PC-5 0 35 90.56

[0124] Table 5 Results of UV resistance test

[0125]

[0126] Note: This represents the amount of color change; the smaller the value, the less noticeable the color change.

[0127] As can be seen from Table 1, the isosorbide-based polycarbonate of each embodiment of the present invention has a high melt flow rate, good fluidity, and good processing performance.

[0128] As shown in Table 2, with the increase of HBPA content, the tensile strength of polycarbonate gradually decreases, while the elongation at break gradually increases. By controlling the molar ratio of ISB and HBPA within the range of this invention, HBPA has a suitable effect on promoting molecular chain growth, moderately reducing the rigidity of isosorbide-based polycarbonate, thus giving it better processing performance and toughness.

[0129] As shown in Table 3, with the increase of HBPA and the decrease of ISB, the Tg value of polycarbonate gradually decreases, and the thermal stability gradually decreases. By controlling the molar ratio of ISB and HBPA within the range of this invention, polycarbonate can have suitable rigid and flexible segments, thereby achieving a controllable glass transition temperature and high thermal stability.

[0130] As shown in Table 4, the synergistic effect between ISB and HBPA may disrupt their molecular chain arrangement, improve the crystalline structure of polycarbonate, and reduce light refraction and scattering at the interface between crystalline and amorphous regions. Simultaneously, their synergistic effect may increase the free volume between molecular chains, reducing the obstruction to light propagation within the material. Furthermore, the synergistic polymerization of these two monomers may alter the vibrational modes of certain chemical bonds and the electron cloud distribution, thus reducing the absorption of polycarbonate in the visible light range. It is speculated that the improved light transmittance of polycarbonate is due to these factors. In particular, the inventors unexpectedly discovered that the isosorbide-based polycarbonate of this invention exhibits significantly improved transparency when the amount of HBPA is 25-30% of the total molar amount of ISB and HBPA, and the amount of ISB is 70-75% of the total molar amount of ISB and HBPA.

[0131] As shown in Table 5, the synergistic effect between ISB and HBPA can, to some extent, prevent UV-induced chain segment movement and degradation reactions. Furthermore, since HBPA lacks the benzene ring conjugated system of BPA, it can reduce or avoid the occurrence of electrons transitioning to excited states after UV absorption. These excited-state electrons may react with surrounding chemical bonds, leading to bond breakage or oxidation. After absorbing UV light, the HBPA unit, due to its relatively saturated structure, is less prone to the violent reactions between excited-state electrons and surrounding chemical bonds as seen in BPA, thus reducing the possibility of UV chemical degradation. It is speculated that through these factors, the color change of polycarbonate prepared with HBPA after UV irradiation is significantly lower than that of polycarbonate using BPA. Therefore, the isosorbide-based polycarbonate of this invention exhibits significantly improved UV resistance.

[0132] In summary, the isosorbide-based polycarbonate of this invention exhibits excellent overall performance through the synergistic effect between ISB and HBPA. It possesses a controllable glass transition temperature while also demonstrating high UV resistance, processability, optical properties, mechanical properties, and thermal stability. Furthermore, the preparation method of this invention is simple, does not involve the use of toxic reagents or monomers, and the catalyst does not require recovery.

[0133] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing isosorbide-based polycarbonate with controllable glass transition temperature, comprising the following steps: The isosorbide-type polycarbonate with controllable glass transition temperature is obtained by subjecting carbonate diester, isosorbide and hydrogenated bisphenol A to at least transesterification and polycondensation reactions in the presence of a catalyst. The amount of hydrogenated bisphenol A used is 15-35% of the total molar amount of isosorbide and hydrogenated bisphenol A, and the amount of isosorbide used is 65-85% of the total molar amount of isosorbide and hydrogenated bisphenol A; the molar ratio of the carbonate diester to the total amount of isosorbide and hydrogenated bisphenol A is (1.01-1.05):

1.

2. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 1, wherein, The carbonate diester includes one or more of dimethyl carbonate, diphenyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, and dioctyl carbonate.

3. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 2, wherein, The carbonate diester is diphenyl carbonate.

4. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 1, wherein, The catalyst comprises one or more of the following: sodium hydroxide, cesium carbonate, lithium acetylacetonate, lithium chloride, tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, methyl titanate, trimethyl phosphate, triethyl phosphate, and triphenyl phosphate.

5. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 4, wherein, The amount of catalyst used is 0.001 to 1 ppm of the mass of the diester.

6. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 1, wherein, The preparation method further includes raw material pulping before the transesterification reaction and polycondensation reaction. The raw material pulping includes: mixing diester, isosorbide and hydrogenated bisphenol A in a protective gas atmosphere, pulping at 100-150°C for 0.5-1 h, and then adding a catalyst.

7. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 1, wherein, The conditions for the transesterification reaction include: a reaction temperature of 150–200°C, a pressure of 30–60 kPa, and a time of 1–2 h.

8. The method for preparing isosorbide-based polycarbonate with controllable glass transition temperature according to claim 1, wherein, The conditions for the polycondensation reaction include: a reaction temperature of 200–250°C, a pressure of 100–300 Pa, and a time of 1–3 h.

9. An isosorbide-based polycarbonate with a controllable glass transition temperature, which is prepared by the method for preparing isosorbide-based polycarbonate with a controllable glass transition temperature according to any one of claims 1-8.

10. The isosorbide-based polycarbonate with controllable glass transition temperature according to claim 9, wherein, The structural formula of the isosorbide-based polycarbonate with controllable glass transition temperature is shown in Formula I: In Formula I, n = 25 to 100.

11. The isosorbide-based polycarbonate with controllable glass transition temperature according to claim 9, wherein, The isosorbide-based polycarbonate with a controllable glass transition temperature has a number-average molecular weight of 10,000–40,000 g / mol; and / or The glass transition temperature of the isosorbide-based polycarbonate with controllable glass transition temperature is 80–135°C; and / or The isosorbide-based polycarbonate with a controllable glass transition temperature has a melt flow rate of 5–70 g / 10 min; and / or The isosorbide-based polycarbonate with a controllable glass transition temperature has an elongation at break of 10–30% and a tensile strength of 58–75 MPa; and / or The isosorbide-based polycarbonate with a controllable glass transition temperature has a light transmittance of 85-92%.

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