Isosorbide-based polycarbonate and preparation method thereof

Abstract

The invention relates to the technical field of preparation of isosorbide-based polycarbonate, in particular to isosorbide-based polycarbonate and a preparation method thereof. The method comprises the following steps: (1) mixing isosorbide, diphenyl carbonate and a metal-organic complex, and then carrying out transesterification to obtain a transesterification product; (2) carrying out condensation polymerization on the ester exchange product to obtain isosorbide-based polycarbonate; wherein the metal-organic complex comprises metal ions and anionic ligands, the metal ions are selected from one or more of titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony and bismuth ions, and the anionic ligands are from tetracarboxylic acid compounds. According to the preparation method of the isosorbide-based polycarbonate, provided by the invention, the isosorbide-based polycarbonate which is large in number-average molecular weight, good in thermal stability, low in brittleness, good in color and luster and high in mechanical strength can be prepared under mild conditions.

Description

Technical Field

[0001] The invention relates to the technical field of isosorbide-based polycarbonate preparation, and in particular to isosorbide-based polycarbonate and a preparation method thereof. Background Art

[0002] Polycarbonate generally uses bisphenol compounds as monomer components. It has high light transmittance, high impact resistance, high toughness, high heat resistance, weather resistance and excellent electrical insulation. It is widely used in the automotive industry, instrumentation, electronic appliances and other fields.

[0003] Existing polycarbonates are usually manufactured using raw materials derived from petroleum resources. With the requirements of carbon neutrality, carbon emission reduction, carbon peak and related environmental protection requirements, the use of raw materials obtained from biomass resources such as plants to prepare polycarbonates has received increasing attention. In addition, global warming caused by the increase and accumulation of carbon dioxide emissions will lead to climate change. It is particularly important to seek to develop a process for polycarbonate using plant-derived monomers as raw materials that can be carbon neutral after use and disposal.

[0004] The methods disclosed in CN105646817A, CN111138650A, CN101896536A and CN107674190A involve using metal or metal oxide as catalyst to prepare polycarbonate. However, the metal catalyst is likely to remain in the polycarbonate to color it, resulting in poor color of the polycarbonate.

[0005] CN110982054A discloses a method in which a supported catalyst containing both a nano catalyst and an amino acid ionic liquid catalyst is used as a catalyst to prepare polycarbonate. The catalyst has a complex process, is prone to produce impurities, affects the catalytic effect, and is not suitable for large-scale expansion.

[0006] CN105218802A uses one or more of alkali metal fatty acid salts, alkali metal fatty diacid salts, or alkali metal alcohol salts and aromatic borate and aromatic phosphate as catalysts to prepare polycarbonate. The reaction temperature of this method is high and the reaction conditions are harsh.

[0007] In CN112979936A, a low eutectic solvent is used as a catalyst to prepare polycarbonate, and the obtained polycarbonate has poor mechanical properties. In CN111393628A, an organic metal complex is used as a catalyst to prepare polycarbonate prepolymer, and the obtained isosorbide-based polycarbonate has poor mechanical properties. Summary of the invention

[0008] The purpose of the present invention is to solve the problems of harsh preparation conditions, low product molecular weight, poor color, poor mechanical strength, etc. of isosorbide-based polycarbonate in the prior art, and to provide an isosorbide-based polycarbonate and a preparation method thereof.

[0009] A first aspect of the present invention provides a method for preparing isosorbide-based polycarbonate, wherein the method comprises the following steps:

[0010] (1) mixing isosorbide, diphenyl carbonate and a metal-organic complex and performing an ester exchange reaction to obtain an ester exchange product;

[0011] (2) subjecting the transesterification product to a condensation polymerization reaction to obtain an isosorbide-based polycarbonate;

[0012] The metal-organic complex comprises metal ions and anionic ligands, wherein the metal ions are selected from one or more of titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony, and bismuth ions, and the anionic ligands are derived from tetracarboxylic acid compounds.

[0013] Preferably, the metal ions are selected from one or more of zirconium, nickel, zinc and aluminum ions;

[0014] And / or, the tetracarboxylic acid-based compound is selected from one or more of pyromellitic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, and pyrene-1,3,6,8-tetracarboxylic acid;

[0015] And / or, in the metal-organic complex, the content of the metal ion is 6-16wt%, preferably 8-12wt%.

[0016] Preferably, the method for synthesizing the metal-organic complex comprises: performing a complexation reaction on a metal salt and a tetracarboxylic acid-based compound in a solution with a pH value of 5.5-9.5 to obtain the metal-organic complex.

[0017] Preferably, the metal salt is selected from one or more soluble compounds containing titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony, and bismuth;

[0018] And / or, the pH value of the solution is 6-8;

[0019] and / or, the molar ratio of the metal salt to the tetracarboxylic acid-based compound is 1:0.2-1.2;

[0020] And / or, the operating conditions of the complex reaction include: the complex reaction is carried out under closed conditions, the complex reaction temperature is 120-180° C., and the complex reaction time is 30-200 h.

[0021] Preferably, the pH value of the solution is 6.5-7.5;

[0022] And / or, the molar ratio of the metal salt to the tetracarboxylic acid-based compound is 1:0.5-0.8;

[0023] And / or, the operating conditions of the complex reaction include: the complex reaction is carried out under closed conditions, the complex reaction temperature is 140-160° C., and the complex reaction time is 70-120 h.

[0024] Preferably, the molar ratio of isosorbide, diphenyl carbonate and metal-organic complex is 1:0.5-2:(0.5-5)×10 -5 ;

[0025] And / or, the mixing comprises: firstly mixing isosorbide and diphenyl carbonate and then melting them to obtain a molten mixture, and then adding the metal-organic complex to the molten mixture;

[0026] And / or, the melting operation conditions include: melting temperature of 60-90° C., melting time of 0.5-2 h.

[0027] Preferably, the molar ratio of isosorbide, diphenyl carbonate and metal-organic complex is 1:0.8-1.2:(1-3)×10 -5 ;

[0028] And / or, the melting operation conditions include: melting temperature of 70-80° C., melting time of 0.5-1 h.

[0029] Preferably, the operating conditions of the transesterification reaction include: the transesterification reaction temperature is 80-180° C., the transesterification reaction pressure is 50-400 Pa, and the transesterification reaction time is 0.2-2.5 h.

[0030] Preferably, the operating conditions of the transesterification reaction include: the transesterification reaction temperature is 100-150° C., the transesterification reaction pressure is 100-300 Pa, and the transesterification reaction time is 0.5-1.5 h.

[0031] Preferably, the operating conditions of the polycondensation reaction include: the polycondensation reaction temperature is 150-300° C., the polycondensation reaction pressure is 10-150 Pa, and the polycondensation reaction time is 0.5-4.5 h.

[0032] Preferably, the operating conditions of the polycondensation reaction include: the polycondensation reaction temperature is 180-250° C., the polycondensation reaction pressure is 30-80 Pa, and the polycondensation reaction time is 1-2 h.

[0033] Preferably, after the polycondensation reaction is completed, a polycondensation product is obtained, and the polycondensation product is extruded to obtain isosorbide-based polycarbonate;

[0034] And / or, the extrusion is carried out in a screw extruder, and the operating conditions of the extrusion include: an extrusion temperature of 220-270° C., an extrusion pressure of 1.5-4 MPa, and an extrusion speed of 200-600 rpm.

[0035] Preferably, the extrusion operating conditions include: extrusion temperature of 240-260° C., extrusion pressure of 2-3 MPa, and extrusion speed of 300-500 rpm.

[0036] The second aspect of the present invention provides an isosorbide-based polycarbonate prepared by the method for preparing isosorbide-based polycarbonate described in the first aspect of the present invention;

[0037] The number average molecular weight of the isosorbide-based polycarbonate is 70,000-130,000 g / mol, and the PDI molecular distribution is 1.7-2.1.

[0038] Preferably, the isosorbide-based polycarbonate has a lightness value L* of 80-95, a red / green value a* of 0.1-1.1, and a yellow / blue value b* of 1-3.5;

[0039] And / or, the isosorbide-based polycarbonate has a tensile strength of 70-85 MPa, a tensile strain of 65-80%, and a cantilever impact strength of 6.5-9 kJ / m 2 .

[0040] Through the above technical solution, the beneficial technical effects achieved by the present invention are as follows:

[0041] The preparation method of isosorbide-based polycarbonate provided by the present invention uses a metal-organic complex obtained by complexing a tetracarboxylic acid-based compound with a metal as a catalyst, and can prepare under mild conditions a polycarbonate having a number average molecular weight of 70,000-130,000 g / mol, a PDI molecular distribution of 1.7-2.1, a lightness value L* of 80-95, a red / green value a* of 0.1-1.1, a yellow / blue value b* of 1-3.5, a tensile strength of 70-85 MPa, a tensile strain of 65-80%, and a cantilever impact strength of 6.5-9 kJ / m 2 The isosorbide-based polycarbonate of the present invention has a large number average molecular weight, good thermal stability, low brittleness, good color, high mechanical strength, and has broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the infrared characterization image of the isosorbide-based polycarbonate prepared in Example 1. DETAILED DESCRIPTION

[0043] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0044] A first aspect of the present invention provides a method for preparing isosorbide-based polycarbonate, wherein the method comprises the following steps:

[0045] (1) mixing isosorbide, diphenyl carbonate and a metal-organic complex and performing an ester exchange reaction to obtain an ester exchange product;

[0046] (2) subjecting the transesterification product to a condensation polymerization reaction to obtain an isosorbide-based polycarbonate;

[0047] The metal-organic complex comprises metal ions and anionic ligands, wherein the metal ions are selected from one or more of titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony, and bismuth ions, and the anionic ligands are derived from tetracarboxylic acid compounds.

[0048] In step (1):

[0049] In some embodiments of the present invention, the metal ions are selected from one or more of zirconium, nickel, zinc, and aluminum ions, preferably nickel and / or zinc ions.

[0050] In some embodiments of the present invention, the tetracarboxylic acid-based compound is selected from one or more of pyromellitic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid and pyrene-1,3,6,8-tetracarboxylic acid, preferably pyromellitic acid.

[0051] In some embodiments of the present invention, in the metal-organic complex, the content of the metal ion is 6-16 wt %, preferably 8-12 wt %.

[0052] In some embodiments of the present invention, the method for synthesizing the metal-organic complex comprises: performing a complex reaction on a metal salt and a tetracarboxylic acid-based compound in a solution with a pH value of 5.5-9.5 to obtain the metal-organic complex.

[0053] Preferably, the metal salt is selected from one or more soluble compounds containing titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony, and bismuth. The soluble compound of the metal salt can be sulfate, phosphate, nitrate, chloride, etc. of the metal element.

[0054] Preferably, the solution is selected from water and / or alcohol, preferably water. The pH value of the solution is preferably 6-8, more preferably 6.5-7.5. In the present invention, the pH value of the solution is adjusted by adding an alkaline component, and the alkaline component is at least one or more selected from potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate, preferably potassium carbonate.

[0055] Preferably, the molar ratio of the metal salt to the tetracarboxylic acid-based compound is 1:0.2-1.2, preferably 1:0.5-0.8.

[0056] Preferably, the operating conditions of the complex reaction include: the complex reaction is carried out under closed conditions, the complex reaction temperature is 120-180°C, preferably 140-160°C; the complex reaction time is 30-200h, preferably 70-120h.

[0057] Preferably, after the complex reaction is completed, the generated precipitate is separated and washed to obtain the metal-organic complex; wherein the purity of the metal-organic complex is ≥98.5%, preferably 99-99.5%.

[0058] In some embodiments of the present invention, the molar ratio of isosorbide, diphenyl carbonate and metal-organic complex is 1:0.5-2:(0.5-5)×10 -5 , preferably 1:0.8-1.2:(1-3)×10 -5 .

[0059] In some embodiments of the present invention, the mixing includes: firstly mixing isosorbide and diphenyl carbonate and then melting them to obtain a molten mixture, and then adding the metal-organic complex to the molten mixture. The melting operation conditions include: a melting temperature of 60-90°C, preferably 70-80°C; a melting time of 0.5-2h, preferably 0.5-1h.

[0060] In some embodiments of the present invention, the operating conditions of the transesterification reaction include: the transesterification reaction temperature is 80-180°C, preferably 100-150°C; the transesterification reaction pressure is 50-400Pa, preferably 100-300Pa; the transesterification reaction time is 0.2-2.5h, preferably 0.5-1.5h.

[0061] In step (2):

[0062] In some embodiments of the present invention, the operating conditions of the polycondensation reaction include: the polycondensation reaction temperature is 150-300°C, preferably 180-250°C; the polycondensation reaction pressure is 10-150Pa, preferably 30-80Pa; the polycondensation reaction time is 0.5-4.5h, preferably 1-2h.

[0063] In some embodiments of the present invention, after the polycondensation reaction is completed, a polycondensation product is obtained, and the polycondensation product is extruded to obtain isosorbide-based polycarbonate.

[0064] In some embodiments of the present invention, the extrusion is carried out in a screw extruder, and the operating conditions of the extrusion include: an extrusion temperature of 220-270°C, preferably 240-260°C; an extrusion pressure of 1.5-4MPa, preferably 2-3MPa; an extrusion speed of 200-600rmp, preferably 300-500rmp.

[0065] The second aspect of the present invention provides an isosorbide-based polycarbonate prepared by the preparation method of isosorbide-based polycarbonate described in the first aspect of the present invention; wherein the number average molecular weight of the isosorbide-based polycarbonate is 70,000-130,000 g / mol, and the PDI molecular distribution is 1.7-2.1.

[0066] In some embodiments of the present invention, the isosorbide-based polycarbonate has a lightness value L* of 80-95, a red / green value a* of 0.1-1.1, and a yellow / blue value b* of 1-3.5.

[0067] In some embodiments of the present invention, the isosorbide-based polycarbonate has a tensile strength of 70-85, a tensile strain of 65-80%, and a cantilever impact strength of 6.5-9 kJ / m 2 .

[0068] The present invention will be described in detail below through examples.

[0069] Example 1

[0070] Preparation of metal-organic complexes:

[0071] Zinc nitrate and pyromellitic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6.5, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zinc nitrate to pyromellitic acid is 1:0.5, the complex reaction temperature is 160°C, and the complex reaction time is 72h.

[0072] Preparation of Isosorbide-Based Polycarbonate

[0073] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:0.8 and then melted at 75°C for 1 hour to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 200 Pa, 100°C, and 1.5 hours to obtain an ester exchange product. The molar ratio of isosorbide to the metal-organic complex is 1:1×10 -5 ;

[0074] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 50 Pa, 180° C., and 1.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 240° C., 2 MPa, and 300 rpm to obtain isosorbide-based polycarbonate.

[0075] The obtained isosorbide-based polycarbonate was characterized by infrared spectroscopy. Figure 1 As shown. Figure 1 It can be seen that isosorbide-based polycarbonate can be obtained by the method in Example 1.

[0076] Example 2

[0077] Preparation of metal-organic complexes:

[0078] Nickel nitrate and pyromellitic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 7, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of nickel nitrate to pyromellitic acid is 1:0.8, the complex reaction temperature is 150°C, and the complex reaction time is 96h.

[0079] Preparation of Isosorbide-Based Polycarbonate

[0080] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1 and then melted at 75°C for 1 hour to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 100 Pa, 120°C, and 1 hour to obtain an ester exchange product. The molar ratio of isosorbide to the metal-organic complex is 1:3×10 -5 ;

[0081] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 80 Pa, 200° C., and 2 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 260° C., 3 MPa, and 500 rpm to obtain isosorbide-based polycarbonate.

[0082] Example 3

[0083] Preparation of metal-organic complexes:

[0084] Zinc nitrate and pyromellitic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 7.5, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zinc nitrate to pyromellitic acid is 1:0.7, the complex reaction temperature is 140°C, and the complex reaction time is 120h.

[0085] Preparation of Isosorbide-Based Polycarbonate

[0086] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.2, and then melted at 75°C for 1 hour to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 300 Pa, 140°C, and 0.5 hour to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:2.5×10 -5 ;

[0087] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 30 Pa, 230° C., and 1 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 250° C., 2 MPa, and 350 rpm to obtain isosorbide-based polycarbonate.

[0088] Example 4

[0089] Preparation of metal-organic complexes:

[0090] Zirconium nitrate and pyrene-1,3,6,8-tetracarboxylic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zirconium nitrate to pyrene-1,3,6,8-tetracarboxylic acid is 1:0.3, the complex reaction temperature is 120°C, and the complex reaction time is 144h.

[0091] Preparation of Isosorbide-Based Polycarbonate

[0092] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.5, and then melted at 65°C for 2 hours to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 350 Pa, 90°C, and 2.5 hours to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:0.5×10 -5 ;

[0093] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 70 Pa, 300° C., and 0.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 220° C., 1.5 MPa, and 200 rpm to obtain isosorbide-based polycarbonate.

[0094] Example 5

[0095] Preparation of metal-organic complexes:

[0096] Aluminum nitrate and 1,4,5,8-naphthalenetetracarboxylic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 8, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of aluminum nitrate to 1,4,5,8-naphthalenetetracarboxylic acid is 1:1, the complex reaction temperature is 180°C, and the complex reaction time is 48h.

[0097] Preparation of Isosorbide-Based Polycarbonate

[0098] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:0.5, and then melted at 80°C for 0.5h to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 50Pa, 160°C, and 0.2h to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:4×10 -5 ;

[0099] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 20 Pa, 150° C., and 4 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 270° C., 3.5 MPa, and 600 rpm to obtain isosorbide-based polycarbonate.

[0100] Example 6

[0101] The same as Example 4, except that zirconium nitrate is replaced by an equimolar amount of zinc nitrate, that is:

[0102] Preparation of metal-organic complexes:

[0103] Zinc nitrate and pyrene-1,3,6,8-tetracarboxylic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zinc nitrate to pyrene-1,3,6,8-tetracarboxylic acid is 1:0.3, the complex reaction temperature is 120°C, and the complex reaction time is 144h.

[0104] Preparation of Isosorbide-Based Polycarbonate

[0105] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.5, and then melted at 65°C for 2 hours to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 350 Pa, 90°C, and 2.5 hours to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:0.5×10 -5 ;

[0106] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 70 Pa, 300° C., and 0.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 220° C., 1.5 MPa, and 200 rpm to obtain isosorbide-based polycarbonate.

[0107] Example 7

[0108] The same as Example 4, the difference is that pyrene-1,3,6,8-tetracarboxylic acid is replaced by an equal molar amount of pyromellitic acid, that is:

[0109] Preparation of metal-organic complexes:

[0110] Zirconium nitrate and pyromellitic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zirconium nitrate to pyromellitic acid is 1:0.3, the complex reaction temperature is 120°C, and the complex reaction time is 144h.

[0111] Preparation of Isosorbide-Based Polycarbonate

[0112] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.5, and then melted at 65°C for 2 hours to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 350 Pa, 90°C, and 2.5 hours to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:0.5×10 -5 ;

[0113] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 70 Pa, 300° C., and 0.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 220° C., 1.5 MPa, and 200 rpm to obtain isosorbide-based polycarbonate.

[0114] Example 8

[0115] The same as Example 4, except that zirconium nitrate is replaced by an equal molar amount of titanium nitrate, and pyrene-1,3,6,8-tetracarboxylic acid is replaced by an equal molar amount of 1,2,4,5-cyclohexanetetracarboxylic acid, that is:

[0116] Preparation of metal-organic complexes:

[0117] Titanium nitrate and 1,2,4,5-cyclohexanetetracarboxylic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of titanium nitrate to 1,2,4,5-cyclohexanetetracarboxylic acid is 1:0.3, the complex reaction temperature is 120°C, and the complex reaction time is 144h.

[0118] Preparation of Isosorbide-Based Polycarbonate

[0119] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.5, and then melted at 65°C for 2 hours to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 350 Pa, 90°C, and 2.5 hours to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:0.5×10 -5 ;

[0120] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 70 Pa, 300° C., and 0.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 220° C., 1.5 MPa, and 200 rpm to obtain isosorbide-based polycarbonate.

[0121] Example 9

[0122] The same as Example 4, the difference is that the molar ratio of zirconium nitrate to pyrene-1,3,6,8-tetracarboxylic acid is 1:0.6, that is:

[0123] Preparation of metal-organic complexes:

[0124] Zirconium nitrate and pyrene-1,3,6,8-tetracarboxylic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zirconium nitrate to pyrene-1,3,6,8-tetracarboxylic acid is 1:0.6, the complex reaction temperature is 120°C, and the complex reaction time is 144h.

[0125] Preparation of Isosorbide-Based Polycarbonate

[0126] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.5, and then melted at 65°C for 2 hours to obtain a molten mixture. Then, the molten mixture and the above metal-organic complex are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 350 Pa, 90°C, and 2.5 hours to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:0.5×10 -5 ;

[0127] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 70 Pa, 300° C., and 0.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 220° C., 1.5 MPa, and 200 rpm to obtain isosorbide-based polycarbonate.

[0128] Example 10

[0129] The same as Example 4, the difference is that isosorbide, diphenyl carbonate and metal-organic complex are mixed together, that is:

[0130] Preparation of metal-organic complexes:

[0131] Zirconium nitrate and pyrene-1,3,6,8-tetracarboxylic acid are added to deionized water, stirred evenly and placed in a reactor, potassium carbonate is added to adjust the pH value of the solution to 6, and a complex reaction is carried out in a sealed state. After the reaction is completed, the temperature is cooled to room temperature, and the crystals are separated and washed by centrifugation to obtain a metal-organic complex; wherein the molar ratio of zirconium nitrate to pyrene-1,3,6,8-tetracarboxylic acid is 1:0.3, the complex reaction temperature is 120°C, and the complex reaction time is 144h.

[0132] Preparation of Isosorbide-Based Polycarbonate

[0133] 1. First, isosorbide, diphenyl carbonate and metal-organic complex are mixed and melted at 65°C for 2h, and then added into the transesterification reactor to carry out transesterification reaction at 350Pa, 90°C, and 2.5h to obtain transesterification product; wherein the molar ratio of isosorbide to metal-organic complex is 1:0.5×10 -5 ;

[0134] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 70 Pa, 300° C., and 0.5 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 220° C., 1.5 MPa, and 200 rpm to obtain isosorbide-based polycarbonate.

[0135] The preparation conditions of the metal-organic complexes in Examples 1-10 are summarized in Table 1, and the preparation conditions of the isosorbide-based polycarbonates in Examples 1-10 are summarized in Table 2.

[0136] Table 1

[0137]

[0138] Note: The molar ratios in Table 1 refer to the molar ratios of the metal salt and the tetracarboxylic acid-based compound.

[0139] Table 2

[0140]

[0141]

[0142] Note: The molar ratios* in Table 2 refer to the molar ratios of isosorbide, diphenyl carbonate and metal-organic complex.

[0143] Comparative Example 1

[0144] The same as Example 3, except that the preparation of the metal-organic complex is omitted, and the metal-organic complex is replaced by an equal mass of tetraethylammonium hydroxide, that is:

[0145] Preparation of Isosorbide-Based Polycarbonate

[0146] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.2, and then melted at 75°C for 1 hour to obtain a molten mixture. Then, the molten mixture and tetraethylammonium hydroxide are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 300 Pa, 140°C, and 0.5 hour to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:2.5×10 -5 ;

[0147] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 30 Pa, 230° C., and 1 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 250° C., 2 MPa, and 350 rpm to obtain isosorbide-based polycarbonate.

[0148] Comparative Example 2

[0149] The same as Example 3, except that the preparation of the metal-organic complex is omitted, and the metal-organic complex is replaced by an equal mass of lithium acetylacetonate, that is:

[0150] Preparation of Isosorbide-Based Polycarbonate

[0151] 1. First, isosorbide and diphenyl carbonate are mixed in a molar ratio of 1:1.2, and then melted at 75°C for 1 hour to obtain a molten mixture. Then, the molten mixture and lithium acetylacetonate are added to an ester exchange reactor, and an ester exchange reaction is carried out under the conditions of 300 Pa, 140°C, and 0.5 hour to obtain an ester exchange product; wherein the molar ratio of isosorbide to the metal-organic complex is 1:2.5×10 -5 ;

[0152] 2. The obtained ester exchange product is introduced into a polycondensation reactor, and a polycondensation reaction is carried out under the conditions of 30 Pa, 230° C., and 1 h to obtain a polycondensation product; the obtained polycondensation product is introduced into a screw extruder, and extruded under the conditions of 250° C., 2 MPa, and 350 rpm to obtain isosorbide-based polycarbonate.

[0153] Sample testing

[0154] The number average molecular weight, PDI molecular weight distribution, color value, and mechanical properties (tensile strength, tensile strain, and cantilever impact strength) of the isosorbide-based polycarbonate prepared in the examples and comparative examples were tested. The results are shown in Table 3.

[0155] The metal ion content was measured by UV spectrophotometer, the number average molecular weight and PDI molecular weight distribution were tested by gel permeation chromatography, and the mechanical properties were tested according to ISO527 and ISO179.

[0156] Color values ​​are measured according to CIELAB. (CIE, Commission Internationale de L'Eclairage, the abbreviation of the International Commission on Illumination, develops international standards for measuring color. CIE developed L*, a* and b* values ​​to measure color values, and this measurement method is called CIELAB. Among them, L* represents lightness, ranging from bright (L*=100 at this time) to dark (L*=0 at this time). a* represents the red / green value, and b* represents the yellow / blue value.

[0157] Table 3

[0158]

[0159] The purity of the metal-organic complex synthesized in the present invention is above 98.5%. As shown in Table 3, the isosorbide-based polycarbonate provided in the present invention has a large number average molecular weight, good thermal stability, low brittleness, good color, high mechanical strength, and has broad market application prospects.

[0160] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing isosorbide-based polycarbonate, characterized in that: The method comprises the following steps: (1) mixing isosorbide, diphenyl carbonate and a metal-organic complex and performing an ester exchange reaction to obtain an ester exchange product; (2) subjecting the transesterification product to a condensation polymerization reaction to obtain an isosorbide-based polycarbonate; The metal-organic complex comprises metal ions and anionic ligands, wherein the metal ions are selected from one or more of titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony, and bismuth ions, and the anionic ligands are derived from tetracarboxylic acid compounds.

2. The preparation method according to claim 1, wherein The metal ions are selected from one or more of zirconium, nickel, zinc and aluminum ions; And / or, the tetracarboxylic acid-based compound is selected from one or more of pyromellitic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, and pyrene-1,3,6,8-tetracarboxylic acid; And / or, in the metal-organic complex, the content of the metal ion is 6-16wt%.

3. The preparation method according to claim 1, wherein The synthesis method of the metal-organic complex comprises: performing a complex reaction on a metal salt and a tetracarboxylic acid-based compound in a solution with a pH value of 5.5-9.5 to obtain the metal-organic complex.

4. The preparation method according to claim 3, wherein The metal salt is selected from one or more soluble compounds containing titanium, zirconium, cobalt, nickel, platinum, zinc, aluminum, germanium, tin, lead, antimony, and bismuth; And / or, the pH value of the solution is 6-8; and / or, the molar ratio of the metal salt to the tetracarboxylic acid-based compound is 1:0.2-1.2; And / or, the operating conditions of the complex reaction include: the complex reaction is carried out under closed conditions, the complex reaction temperature is 120-180° C., and the complex reaction time is 30-200 h.

5. The preparation method according to claim 4, wherein The pH value of the solution is 6.5-7.5; And / or, the molar ratio of the metal salt to the tetracarboxylic acid-based compound is 1:0.5-0.8; And / or, the operating conditions of the complex reaction include: the complex reaction is carried out under closed conditions, the complex reaction temperature is 140-160° C., and the complex reaction time is 70-120 h.

6. The preparation method according to claim 1, wherein The molar ratio of isosorbide, diphenyl carbonate and metal-organic complex is 1:0.5-2:(0.5-5)×10 -5 ; And / or, the mixing comprises: firstly mixing isosorbide and diphenyl carbonate and then melting them to obtain a molten mixture, and then adding the metal-organic complex to the molten mixture; And / or, the melting operation conditions include: melting temperature of 60-90° C., melting time of 0.5-2 h.

7. The preparation method according to claim 6, wherein: The molar ratio of isosorbide, diphenyl carbonate and metal-organic complex is 1:0.8-1.2:(1-3)×10 -5 ; And / or, the melting operation conditions include: melting temperature of 70-80° C., melting time of 0.5-1 h.

8. The preparation method according to claim 1, wherein The operating conditions of the transesterification reaction include: the transesterification reaction temperature is 80-180° C., the transesterification reaction pressure is 50-400 Pa, and the transesterification reaction time is 0.2-2.5 h.

9. The preparation method according to claim 8, wherein: The operating conditions of the transesterification reaction include: the transesterification reaction temperature is 100-150° C., the transesterification reaction pressure is 100-300 Pa, and the transesterification reaction time is 0.5-1.5 h.

10. The preparation method according to claim 1, wherein: The operating conditions of the polycondensation reaction include: the polycondensation reaction temperature is 150-300° C., the polycondensation reaction pressure is 10-150 Pa, and the polycondensation reaction time is 0.5-4.5 h.

11. The preparation method according to claim 10, wherein: The operating conditions of the polycondensation reaction include: the polycondensation reaction temperature is 180-250° C., the polycondensation reaction pressure is 30-80 Pa, and the polycondensation reaction time is 1-2 h.

12. The preparation method according to claim 1, wherein: After the polycondensation reaction is completed, a polycondensation product is obtained, and the polycondensation product is extruded to obtain isosorbide-based polycarbonate.

13. The preparation method according to claim 12, wherein: The extrusion is carried out in a screw extruder, and the operating conditions of the extrusion include: an extrusion temperature of 220-270° C., an extrusion pressure of 1.5-4 MPa, and an extrusion speed of 200-600 rpm.

14. The preparation method according to claim 13, wherein: The extrusion operating conditions include: extrusion temperature of 240-260° C., extrusion pressure of 2-3 MPa, and extrusion speed of 300-500 rpm.

15. An isosorbide-based polycarbonate prepared by the preparation method according to any one of claims 1 to 14; in, The number average molecular weight of the isosorbide-based polycarbonate is 70,000-130,000 g / mol, and the PDI molecular distribution is 1.7-2.

1.

16. The isosorbide-based polycarbonate according to claim 15, wherein The isosorbide-based polycarbonate has a lightness value L* of 80-95, a red / green value a* of 0.1-1.1, and a yellow / blue value b* of 1-3.5; And / or, the isosorbide-based polycarbonate has a tensile strength of 70-85 MPa, a tensile strain of 65-80%, and a cantilever impact strength of 6.5-9 kJ / m 2 .

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