CN111393628B

CN111393628B - Application of organic metal complex and preparation method of polycarbonate prepolymer

Info

Publication number: CN111393628B
Application number: CN202010377822.7A
Authority: CN
Inventors: 徐菲; 安宏哲; 方文娟; 李晨浩; 张振才; 杨子锋; 孙玮; 张延强; 张锁江
Original assignee: Institute of Process Engineering of CAS
Current assignee: Institute of Process Engineering of CAS
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2021-11-09
Anticipated expiration: 2040-05-07
Also published as: CN111393628A

Abstract

The invention provides an application of an organic metal complex and a preparation method of a polycarbonate prepolymer. The organic metal complex is a complex of metal cation and organic ligand, and is used as a catalyst for synthesizing polycarbonate by a transesterification method. The preparation method comprises the following steps: and (2) taking carbonic ester and dihydroxy compound as raw materials, and reacting under the catalytic action of the organic metal complex to obtain a polycarbonate prepolymer. The research of the invention finds that the organic metal complex can simultaneously activate carbonic ester and dihydroxy compounds, and the organic metal complex is used as a catalyst for synthesizing polycarbonate by an ester exchange method, so that the occurrence of alkylation side reaction can be effectively reduced, the reaction time is shortened, and the conversion rate and the selectivity of the ester exchange reaction are improved.

Description

Application of organic metal complex and preparation method of polycarbonate prepolymer

Technical Field

The invention belongs to the technical field of polycarbonate synthesis, and particularly relates to application of an organic metal complex and a preparation method of a polycarbonate prepolymer.

Background

Polycarbonate is a high molecular compound containing carbonate groups in molecular chains, has been widely applied in the fields of automobile manufacturing, aerospace, building material industry, electronic and electrical appliances and the like due to excellent impact resistance, flame retardance, light transmittance and the like, and is a universal engineering plastic with the fastest demand among five engineering plastics.

The polycarbonate synthesis process is mainly used for two synthesis processes of an interfacial phosgene polycondensation method and a melt transesterification polycondensation method in industrial production. The interfacial phosgene polycondensation method is a process widely adopted in the industry at present, namely bisphenol A firstly reacts with sodium hydroxide solution to generate sodium salt of bisphenol A, then dichloromethane is added, phosgene is introduced, and a polymer is generated through two stages of prepolymerization and polycondensation.

The melt transesterification method mainly uses diphenyl carbonate and bisphenol A as raw materials to synthesize polycarbonate, although the process avoids the use of phosgene, part of enterprises still adopt the phosgene method in the production process of the raw material diphenyl carbonate, and the byproduct phenol generated after polymerization is difficult to remove. Dimethyl carbonate is a synthetic raw material of diphenyl carbonate, the new process for producing polycarbonate by taking dimethyl carbonate and bisphenol A as raw materials not only avoids phosgene from the source and simplifies the process flow, but also can easily remove the byproduct methanol generated after polymerization from the reaction system, so the process has great industrial prospect.

The synthesis of polycarbonate from dimethyl carbonate is divided into two prepolymerization and polycondensation stages, wherein the prepolymerization stage is mainly characterized in that dimethyl carbonate and bisphenol A react to synthesize monomethyl bisphenol A (prepolymer 1) and dimethyl bisphenol A (prepolymer 2), and the reaction formula is as follows:

the prepolymer is further polycondensed to produce polycarbonate. The purity of the prepolymer and the content of the ester exchange product in the polycondensation stage directly determine the polymerization reaction effect, and the low purity of the prepolymer can cause the reaction in the polycondensation stage to be difficult to carry out. Because the reaction conversion rate of bisphenol A and dimethyl carbonate is low and the selectivity of the prepolymer is poor, the key of the research and development of the process is to improve the reaction conversion rate and the selectivity of the prepolymer. The catalysts currently used in the synthesis of polycarbonate prepolymers from dimethyl carbonate can be divided into two categories: homogeneous catalysts and heterogeneous catalysts. In 1999, Haba et al first proposed the synthesis of a prepolymer using an organotin catalyst in the presence of N, N-dimethyl-4-aminopyridine (DMAP) and (Bu)₂SnCl)₂Under the action of O compound catalystThe reaction time was 48 hours, and the yield of prepolymer 2 was 22% [ Journal of Polymer Science, Part A: Polymer Chemistry,1999,37,2087-](ii) a TiO used by Kim et al in 2002₂/SiO₂As a catalyst, the sum of the yields of the two prepolymers was 19.9% [ Journal of Polymer Science,2002,86,937-](ii) a In 2010, Su et al, TiO₂SBA-15 as a catalyst for 10 hours, the yields of prepolymer 1 and prepolymer 2 obtained were 25.3% and 3.6%, respectively [ Journal of Molecular Catalysis: A,2016,424,77-84](ii) a Ph synthesized by He and the like in 2013₂SnO is used for DMC and BPA transesterification, the reaction is carried out for 16h at 180 ℃ under high pressure, and the selectivity of prepolymer 1 in the obtained product is 70% [ Catalysis Communication,2013,33,20-23 ]](ii) a 2019 Liang et al use lithium doped TiO₂As a catalyst, the reaction conversion rate is 46.67%, and the yields of prepolymer 1 and prepolymer 2 are 36.36% and 5.97%, respectively [ Molecular Catalysis,2019,465, 16-23%]. Obviously, the conversion rate of the reaction between BPA and DMC and the ester exchange selectivity still need to be further improved, and the development of a high-efficiency catalyst has great practical significance for the industrialization of preparing polycarbonate from dimethyl carbonate.

Disclosure of Invention

In view of the disadvantages of the prior art, the present invention aims to provide the use of an organometallic complex and a method for preparing a polycarbonate prepolymer. The preparation method adopts the organic metal complex as the catalyst, can simultaneously activate the carbonic ester and the dihydroxy compound, reduces the occurrence of alkylation side reaction, shortens the reaction time, and improves the conversion rate and the selectivity of the ester exchange reaction.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides the use of an organometallic complex as a catalyst for the synthesis of polycarbonate by the transesterification process;

the organometallic complex is a complex of a metal cation and an organic ligand;

the metal cation is selected from any one of transition metal ions, lanthanide metal ions and metal ions in groups IA-IIIA of the periodic Table of the elements;

the organic ligand is selected from any one of the following compounds:

wherein R is₁Is selected from-CH₃、-C₂H₅、-C₃H₇and-C₄H₉Any one of them.

The reaction formula of the prepolymerization stage for synthesizing the polycarbonate by the ester exchange method is as follows:

ester exchange reaction:

alkylation side reaction:

when the existing catalyst (such as metal oxide and metal alkyl compound) is used for catalyzing and synthesizing polycarbonate, the defects of more side reactions, low ester exchange reaction selectivity, low polycarbonate prepolymer yield and the like exist generally because the single-active-site catalysis is mainly adopted and the steric hindrance is small, and the methyl esterification and the methylation reaction of the carbonate are easy to activate simultaneously. The inventor finds that when the organic metal complex with the structure is used as a catalyst for synthesizing polycarbonate by an ester exchange method, part of ligands of the organic metal complex can generate a 'dissociation-reconcile' process with metal in a reaction system, the metal and the ligands respectively react with raw materials, metal atoms can form a complexation effect with oxygen on the carbonate through 3 action modes of cis or trans, carbonyl carbon is easier to attack, the organic ligand can activate hydroxyl of a dihydroxy compound through hydrogen bonds, so that the dihydroxy compound is activated, and finally, the selective synthesis of polycarbonate prepolymer can be realized more efficiently in a shorter time, thereby laying a foundation for synthesizing high-quality polycarbonate.

As a preferred embodiment of the present invention, the metal cation is selected from Zn²⁺、Cu²⁺、Ni²⁺、Co²⁺、Co³⁺、Fe²⁺、Fe³⁺、Mn²⁺、Mn³⁺、Cr³⁺、Cd²⁺、Sc³⁺、Ag⁺、Pd²⁺、Pt²⁺、Ru³⁺、Ir³⁺、Rh³⁺、Zr⁴⁺、Hf⁴⁺、Li⁺、Na⁺、Be²⁺、Mg²⁺、Ca²⁺、Al³⁺、Ga³⁺、In³⁺、La³⁺、Sm³⁺、Gd³⁺、Tb³⁺、Dy³⁺、Er³⁺、Tm³⁺、Yb³⁺And Lu³⁺Any one of them.

As a preferred technical scheme of the invention, the organic metal complex is 1, 10-phenanthroline zinc, 8-hydroxyquinoline zinc, magnesium acetylacetonate, calcium acetylacetonate, aluminum acetylacetonate, zinc acetylacetonate, iron acetylacetonate, cadmium acetylacetonate, zirconium acetylacetonate, manganese acetylacetonate or lanthanum acetylacetonate; further preferred is zirconium acetylacetonate, aluminum acetylacetonate, iron acetylacetonate or cadmium acetylacetonate. The selection of the organometallic complex is helpful for further improving the conversion rate of the transesterification reaction and improving the yield of the polycarbonate prepolymer.

As a preferable technical scheme of the invention, the raw materials for synthesizing the polycarbonate by the ester exchange method are dihydroxy compounds and carbonic ester;

the carbonate is selected from one or a combination of at least two of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dibutylene carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, dicyclopentyl carbonate, dicyclohexyl carbonate, bicycloheptyl carbonate and diphenyl carbonate, and is more preferably dimethyl carbonate.

Preferably, the dihydroxy compound is selected from the group consisting of bisphenol A, ethylene glycol, 1, 2-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 1, 3-hexanediol, 1, 7-heptanediol, diethylene glycol, triethylene glycol, 1, 3-cyclopentanediol, 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, 1, 10-decanediol, 2,4, 4-tetramethyl-1, 3-cyclobutanediol, isosorbide, p-xylene glycol, tricyclodecanedimethanol, 4,4- (9-fluorene) diphenol, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3, 5-dimethylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene, 9-bis (4- (3-hydroxy-2, 2-dimethylpropoxy) phenyl) fluorene, 9-bis (6- (2-hydroxy) naphthyl) fluorene, 9-bis (5- (2-hydroxyethoxy) -1-naphthyl) fluorene, 9-bis (6- (2-hydroxyethoxy) naphthyl) fluorene, 9-bis (3-phenyl-4- (2-hydroxyethoxy) phenyl) fluorene, 9-bis (6- (2-hydroxypropoxy) naphthyl) fluorene, 2 '-bis (2-hydroxy) -1,1' -binaphthyl, 2 '-bis (2-hydroxyethoxy) -1,1' -binaphthyl, 2 '-bis (2-hydroxypropoxy) -1,1' -binaphthyl, 2,2 '-bis (2- (2-hydroxyethoxy) ethoxy) -1,1' -binaphthyl, 4'- (1-phenylethyl) bisphenol, 2-bis (4-hydroxyphenyl) butane, 4' -ethylenebiphenol, 4 '-dihydroxydiphenylmethane, 1, 3-bis [2- (4-hydroxyphenyl) -2-propyl ] benzene, 4' -dihydroxytetraphenylmethane, 2-bis (4-hydroxy-3, 5-dimethylphenyl) propane, 2-bis (4-hydroxy-3-methylphenyl) propane and hydroquinone, or a combination of at least two thereof, further preferably bisphenol A, isosorbide, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene or 1, 4-butanediol.

The ester exchange selectivity of aliphatic carbonates (especially dimethyl carbonate) is poor, the reaction activity is low, and the reaction yield is difficult to improve. The organic metal complex is used as a catalyst, so that the ester exchange selectivity and the ester exchange reaction yield of the carbonate can be effectively improved.

In a second aspect, the present invention provides a method for preparing a polycarbonate prepolymer, the method comprising: taking carbonic ester and dihydroxy compound as raw materials, and reacting under the action of an organic metal complex catalyst to obtain a polycarbonate prepolymer;

the organometallic complex is selected from one or a combination of at least two of complexes of a metal cation and an organic ligand;

the organic ligand is selected from any one of the following compounds:

Preferably, the organometallic complex catalyst is selected from one or a combination of at least two of 1, 10-phenanthroline zinc, 8-hydroxyquinoline zinc, magnesium acetylacetonate, calcium acetylacetonate, aluminum acetylacetonate, zinc acetylacetonate, iron acetylacetonate, cadmium acetylacetonate, zirconium acetylacetonate, manganese acetylacetonate, and lanthanum acetylacetonate; further preferred is one or a combination of at least two selected from zirconium acetylacetonate, aluminum acetylacetonate, iron acetylacetonate, and cadmium acetylacetonate.

In a preferred embodiment of the present invention, the carbonate is selected from one or a combination of at least two of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, dicyclopentyl carbonate, dicyclohexyl carbonate, bicycloheptyl carbonate and diphenyl carbonate, and more preferably dimethyl carbonate.

In a preferred embodiment of the present invention, the molar ratio of the carbonate to the dihydroxy compound is 2 to 50:1, and may be, for example, 1:1, 2:1, 5:1, 8:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, or 50: 1.

In a preferred embodiment of the present invention, the amount of the organometallic complex used is 0.5 to 10% by mole of the dihydroxy compound, and may be, for example, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or the like; further preferably 5 to 10%. The preferable amount of the organic metal complex is advantageous in that the conversion rate of the transesterification reaction can be further improved and the yield of the polycarbonate prepolymer can be improved.

As the preferred technical scheme of the invention, the reaction temperature is 120-; further preferably 140-200 ℃.

Preferably, the reaction time is 0.5 to 24h, and may be, for example, 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 5h, 6h, 8h, 10h, 12h, 15h, 18h, 20h, 24h, or the like; further preferably 4 to 10 hours.

Preferably, the reaction is carried out under a protective atmosphere.

Preferably, the gas of the protective atmosphere is nitrogen, helium, argon, neon or carbon dioxide.

Compared with the prior art, the invention has the following beneficial effects:

compared with the existing metal oxide and metal alkyl compound catalysts, the organic metal complex can simultaneously activate the carbonic ester and the dihydroxy compound, reduces the occurrence of alkylation side reaction, shortens the reaction time, makes the reaction conditions milder, has higher reaction conversion rate and ester exchange selectivity, and provides favorable conditions for further synthesizing high-quality polycarbonate.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

A method for synthesizing a polycarbonate prepolymer comprises the following steps:

4.56g (0.02mol) of bisphenol A were reacted with 0.353g (1X 10 mol) of bisphenol A^-3mol, 5% of bisphenol A mol) of ferric acetylacetonate is added into a reactor, nitrogen is used for replacing air in the reactor, 18g of dimethyl carbonate (0.2mol, the mol ratio of dimethyl carbonate to bisphenol A is 10:1) is dripped into a reaction system after the reaction temperature reaches 180 ℃, the reaction time is 4 hours under normal pressure, a by-product methanol is continuously removed in the reaction process, and nitrogen is introduced for protection in the whole reaction process.

In the embodiment of the invention, the reaction product is analyzed by adopting high performance liquid chromatography with an ultraviolet detector, and a C-18 reverse phase chromatographic column is selected as the chromatographic column. It was found that the conversion of the reaction in this example was 18.5%, the selectivity of the transesterification was 100%, the total yield of the two prepolymers was 15.1%, and the other product was an oligomer formed by further transesterification of the two prepolymers.

In the embodiment of the invention, the two prepolymers are prepolymer 1 and prepolymer 2 which are generated by the following reaction:

example 2

the difference from example 1 is that 0.324g (1X 10) of iron acetylacetonate was substituted^-3mol, 5% of the molar amount of bisphenol A) aluminum acetylacetonate, other barsThe piece is unchanged. The conversion of the reaction was found to be 14.0%, the selectivity of the transesterification was found to be 100%, and the total yield of the two prepolymers was found to be 12.6%.

Example 3

the difference from example 1 is that iron acetylacetonate was replaced with 0.311g (1X 10)^-3mol, 5% of the molar amount of bisphenol A) cadmium acetylacetonate, and the other conditions were unchanged. The conversion of the reaction was found to be 22.1%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 14.5%.

Example 4

the difference from example 1 is that 0.238g (1X 10) of iron acetylacetonate was substituted^-3mol, 5% of the molar amount of bisphenol A) calcium acetylacetonate, otherwise unchanged. It was found that the reaction conversion was 45.4%, the ester exchange selectivity was 75.2%, and the total yield of the two prepolymers was 23.0%.

Example 5

the difference from example 1 is that iron acetylacetonate was replaced with 0.436g (1X 10)^-3mol, 5% of the molar amount of bisphenol A) lanthanum acetylacetonate, otherwise the conditions were unchanged. It was found that the reaction conversion was 45.9%, the ester exchange selectivity was 92.2%, and the total yield of the two prepolymers was 27.8%.

Example 6

the difference from example 1 is that 0.488g (1X 10) of iron acetylacetonate was substituted for^-3mol, 5% of the molar amount of bisphenol A) zirconium acetylacetonate, otherwise unchanged. The conversion of the reaction was found to be 34.7%, the selectivity for the transesterification was found to be 100%, and the total yield of the two prepolymers was found to be 18.4%.

Example 7

the difference from example 1 is that iron acetylacetonate is replaced with 0.106g (1X 10)^-3mol, 5% of the molar amount of bisphenol A) of lithium acetylacetonate, otherwise unchanged. The conversion of the reaction was found to be 75.4%, the ester exchange selectivity was found to be 44.0%, and the total yield of the two prepolymers was found to be 21.3%.

Example 8

the difference from example 1 is that iron acetylacetonate was replaced with 0.511g (1X 10)^-3mol, 5% of the molar amount of bisphenol A) zinc dibenzoylmethane, the other conditions being unchanged. It was found that the reaction conversion was 41.4%, the ester exchange selectivity was 67.2%, and the total yield of the two prepolymers was 22.1%.

Example 9

the difference from example 1 is that 0.354g (1X 10) of iron acetylacetonate was substituted^-3mol, 5% of the molar amount of bisphenol A) of zinc 8-hydroxyquinoline, the other conditions being unchanged. It was found that the reaction conversion was 45.3%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 39.4%.

Example 10

the difference from example 1 is that iron acetylacetonate was replaced with 0.425g (1X 10)^-3mol, 5 percent of the molar weight of the bisphenol A) of 1, 10-o-phenanthroline zinc, and other conditions are not changed. The conversion of the reaction was found to be 34.0%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 24.5%.

Example 11

the difference from example 1 is that 0.0425g (1X 10) of iron acetylacetonate was substituted^-4mol, 0.5 percent of the molar weight of the bisphenol A) of 1, 10-phenanthroline zinc, and other conditions are not changed. The conversion of the reaction was 11.9%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was found to be8.7％。

Example 12

the difference from example 1 is that 0.085g (2X 10) of iron acetylacetonate was substituted for^-4mol, 1 percent of the molar weight of bisphenol A) of 1, 10-o-phenanthroline zinc, and other conditions are not changed. The conversion of the reaction was found to be 14.9%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 10.3%.

Example 13

the difference from example 1 is that 0.160g (4X 10) of iron acetylacetonate was substituted^-4mol, 2 percent of the molar weight of the bisphenol A) of 1, 10-o-phenanthroline zinc, and other conditions are not changed. The conversion of the reaction was found to be 24.3%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 21.3%.

Example 14

the difference from example 1 is that 0.320g (8X 10) of iron acetylacetonate was substituted^-4mol, 4 percent of the molar weight of bisphenol A) of 1, 10-o-phenanthroline zinc, and other conditions are not changed. The conversion of the reaction was found to be 30.3%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 24.1%.

Example 15

the difference from example 1 is that iron acetylacetonate is replaced with 0.850g (2X 10)^-3mol, 10 percent of the molar weight of bisphenol A) 1, 10-o-phenanthroline zinc, and other conditions are not changed. The conversion of the reaction was found to be 39.4%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 25.3%.

Example 16

the difference from example 6 is that zirconium acetylacetonate is used in an amount of 0.975g (2X 1)0^-3mol, 10% of the molar amount of bisphenol A), the other conditions being unchanged. The conversion of the reaction was found to be 64.1%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 45.2%.

Example 17

the difference from example 1 is that iron acetylacetonate is replaced with 0.527g (2X 10)^-3mol, 10% of the molar amount of bisphenol A) zinc acetylacetonate, otherwise unchanged. It was found that the reaction conversion was 59.7%, the ester exchange selectivity was 78.4%, and the total yield of the two prepolymers was 21.3%.

Example 18

the difference from example 1 is that 0.648g (2X 10) of iron acetylacetonate was substituted for^-3mol, 10% of the molar amount of bisphenol A) and 3.6g of dimethyl carbonate (0.04mol, 2:1 molar ratio of dimethyl carbonate to bisphenol A) in total, the other conditions being unchanged. The conversion of the reaction was 6.2%, the selectivity of the transesterification was 100% and the overall yield of the two prepolymers was 6.2%.

Example 19

the difference from example 1 is that 0.648g (2X 10) of iron acetylacetonate was substituted for^-3mol, 10% of the molar amount of bisphenol A) of aluminum acetylacetonate, and 27g of dimethyl carbonate (0.3mol, molar ratio of dimethyl carbonate to bisphenol A15: 1) in total, were added dropwise, with the other conditions being unchanged. It was found that the reaction conversion was 46.9%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 23.8%.

Example 20

the difference from example 1 is that 0.648g (2X 10) of iron acetylacetonate was substituted for^-3mol, 10% of the molar amount of bisphenol A) of aluminum acetylacetonate, and 36g of dimethyl carbonate were added dropwise in total(0.4mol, the molar ratio of dimethyl carbonate to bisphenol A is 20:1), and the other conditions are unchanged. The conversion of the reaction was found to be 48.3%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 25.6%.

Example 21

the difference from example 1 is that 0.648g (2X 10) of iron acetylacetonate was substituted for^-3mol, 10% of the molar amount of bisphenol A) of aluminum acetylacetonate, and 54g of dimethyl carbonate (0.6mol, molar ratio of dimethyl carbonate to bisphenol A30: 1) in total, were added dropwise, with the other conditions being unchanged. It was found that the reaction conversion was 53.2%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 27.3%.

Example 22

the difference from example 1 is that 0.648g (2X 10) of iron acetylacetonate was substituted for^-3mol, 10% of the molar amount of bisphenol A) of aluminum acetylacetonate, and 72g of dimethyl carbonate (0.8mol, 40:1 molar ratio of dimethyl carbonate to bisphenol A) in total were added dropwise, with the other conditions being unchanged. The conversion of the reaction was found to be 62.1%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 37.1%.

Example 23

the difference from example 1 is that 0.648g (2X 10) of iron acetylacetonate was substituted for^-3mol, 10% of the molar amount of bisphenol A) of aluminum acetylacetonate, and 90g of dimethyl carbonate (1mol, molar ratio of dimethyl carbonate to bisphenol A50: 1) in total, were added dropwise, with the other conditions being unchanged. It was found that the reaction conversion was 63.9%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 39.2%.

Example 24

the difference from example 1 is that the catalyst is 0.621g (2X 10)^-3mol, bis10% of the molar weight of the phenol A) of cadmium acetylacetonate, and 27g (0.3mol) of dimethyl carbonate is added dropwise into the reaction system after the reaction temperature reaches 120 ℃, and other conditions are unchanged. It was found that the reaction conversion was 36%, the ester exchange selectivity was 100% and the total yield of the two prepolymers was 25.3%.

Example 25

the difference from example 1 is that the catalyst is 0.621g (2X 10)^-3mol, 10% of bisphenol A mol), 27g (0.3mol) of dimethyl carbonate is dripped into the reaction system when the reaction temperature reaches 140 ℃, and other conditions are not changed. The conversion of the reaction was found to be 38.4%, the selectivity for the transesterification was found to be 100%, and the total yield of the two prepolymers was found to be 27.1%.

Example 26

the difference from example 1 is that the catalyst is 0.621g (2X 10)^-3mol, 10% of bisphenol A mol), 27g (0.3mol) of dimethyl carbonate is dripped into the reaction system when the reaction temperature reaches 160 ℃, and other conditions are not changed. The conversion of the reaction was found to be 45%, the selectivity of the transesterification was found to be 100%, and the total yield of the two prepolymers was found to be 31.3%.

Example 27

the difference from example 1 is that the catalyst is 0.621g (2X 10)^-3mol, 10% of bisphenol A mol), 27g (0.3mol) of dimethyl carbonate is dripped into the reaction system when the reaction temperature reaches 200 ℃, and other conditions are not changed. The conversion of the reaction was found to be 48.3%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 22.3%.

Example 28

the difference from example 1 is that the catalyst is 0.621g (2X 10)^-3mol, 10% of the molar amount of bisphenol A) cadmium acetylacetonate27g (0.3mol) of dimethyl carbonate is added into the reaction system after the reaction temperature reaches 240 ℃, and other conditions are not changed. The conversion of the reaction was found to be 60%, the selectivity of the transesterification was found to be 100%, and the total yield of the two prepolymers was found to be 14.5%.

Example 29

the difference from example 1 is that the catalyst is 0.648g (2X 10)^-3mol, 10% of bisphenol A mol), adding 27g (0.3mol) of dimethyl carbonate dropwise into the reaction system after the temperature reaches 180 ℃, and reacting for 0.5 hour under normal pressure without changing other conditions. The conversion of the reaction was found to be 9.1%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 5.4%.

Example 30

the difference from example 1 is that the catalyst is 0.648g (2X 10)^-3mol, 10% of bisphenol A mol), adding 27g (0.3mol) of dimethyl carbonate dropwise into the reaction system after the temperature reaches 180 ℃, and reacting for 5 hours under normal pressure without changing other conditions. The conversion of the reaction was found to be 49.2%, the selectivity of the transesterification was found to be 100%, and the total yield of the two prepolymers was found to be 30.1%.

Example 31

the difference from example 1 is that the catalyst is 0.648g (2X 10)^-3mol, 10% of bisphenol A mol), adding 27g (0.3mol) of dimethyl carbonate dropwise into the reaction system after the temperature reaches 180 ℃, and reacting for 6 hours under normal pressure without changing other conditions. It was found that the reaction conversion was 63.5%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 43.1%.

Example 32

the difference from example 1 is that the catalyst is 0.648g (2X 10)^-3mol, 10% of bisphenol A mol), adding 27g (0.3mol) of dimethyl carbonate dropwise into the reaction system after the temperature reaches 180 ℃, and reacting for 10 hours under normal pressure without changing other conditions. It was found that the reaction conversion was 67.9%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 37.4%.

Example 33

the difference from example 1 is that the catalyst is 0.648g (2X 10)^-3mol, 10% of bisphenol A mol), adding 27g (0.3mol) of dimethyl carbonate dropwise into the reaction system after the temperature reaches 180 ℃, and reacting for 24 hours under normal pressure without changing other conditions. It was found that the reaction conversion was 72.4%, the ester exchange selectivity was 100% and the total yield of the two prepolymers was 32.8%.

Example 34

the difference from example 1 is that the catalyst is 0.975g (2X 10)^-3mol, 10% of bisphenol A mol), adding 36g (0.4mol) of dimethyl carbonate dropwise into the reaction system when the temperature reaches 180 ℃, and reacting for 0.5 hour under normal pressure, wherein other conditions are not changed. It was found that the reaction conversion was 15.9%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 12.4%.

Example 35

the difference from example 1 is that the catalyst is 0.975g (2X 10)^-3mol, 10% of bisphenol A mol), adding 36g (0.4mol) of dimethyl carbonate dropwise into the reaction system when the temperature reaches 180 ℃, and reacting for 3 hours under normal pressure without changing other conditions. The conversion of the reaction was found to be 37.2%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 17.9%.

Example 36

the difference from example 1 is that the catalyst is 0.975g (2X 10)^-3mol, 10% of bisphenol A mol), adding 36g (0.4mol) of dimethyl carbonate dropwise into the reaction system when the temperature reaches 180 ℃, and reacting for 7 hours under normal pressure without changing other conditions. The conversion of the reaction was found to be 57.1%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 25.8%.

Example 37

the difference from example 1 is that the catalyst is 0.975g (2X 10)^-3mol, 10% of bisphenol A mol), adding 36g (0.4mol) of dimethyl carbonate dropwise into the reaction system when the temperature reaches 180 ℃, and reacting for 15 hours under normal pressure without changing other conditions. It was found that the reaction conversion was 80.2%, the ester exchange selectivity was 100%, and the total yield of the two prepolymers was 40.4%.

Example 38

the difference from example 1 is that the catalyst is 0.975g (2X 10)^-3mol, 10% of bisphenol A mol), adding 36g (0.4mol) of dimethyl carbonate dropwise into the reaction system when the temperature reaches 180 ℃, and reacting for 24 hours under normal pressure without changing other conditions. The conversion of the reaction was found to be 85.2%, the ester exchange selectivity was found to be 100%, and the total yield of the two prepolymers was found to be 33.4%.

Example 39

the difference from example 1 is that bisphenol A was replaced with the same molar amount of 1, 4-butanediol and dimethyl carbonate was replaced with the same molar amount of diethyl carbonate, and the other conditions were not changed. The conversion of the reaction was found to be 85.3%, the ester exchange selectivity was found to be 97.2%, and the total yield of the two prepolymers was found to be 26.8%.

Example 40

the difference from example 1 is that bisphenol A was replaced with the same molar amount of isosorbide and dimethyl carbonate was replaced with the same molar amount of dibutyl carbonate, and the other conditions were not changed. The conversion of the reaction was found to be 95.6%, the ester exchange selectivity was found to be 96.3%, and the total yield of the two prepolymers was found to be 40.2%.

EXAMPLE 41

the difference from example 1 was that bisphenol A was replaced with the same molar amount of 9, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene and dimethyl carbonate was replaced with the same molar amount of diheptyl carbonate, and the other conditions were not changed. The conversion of the reaction was found to be 38.3%, the selectivity for the transesterification was found to be 97.4%, and the total yield of the two prepolymers was found to be 17.9%.

Comparative example 1

A process for preparing a polycarbonate prepolymer was carried out in the same manner as in example 1 except that iron acetylacetonate was replaced with the same molar amount of zirconium dioxide and the other conditions were not changed. The conversion of the reaction was found to be 1.6%, the ester exchange selectivity was found to be 18.9%, and the total yield of the two prepolymers was found to be 0.3%.

Comparative example 2

A method for producing a polycarbonate prepolymer was provided, which was different from example 1 in that iron acetylacetonate was replaced with the same molar amount of aluminum isopropoxide, and other conditions were not changed. The conversion of the reaction was found to be 16.3%, the ester exchange selectivity was found to be 17.2%, and the total yield of the two prepolymers was found to be 2.6%.

As can be seen from a comparison between example 1 of the present application and comparative examples 1 to 2, the organometallic complex according to the present invention can effectively reduce the occurrence of side reactions of alkylation and improve the conversion rate and selectivity of transesterification.

As can be seen by comparing examples 10-15, the reaction conversion, the transesterification selectivity and the overall yield of both prepolymers increased with increasing catalyst usage.

As can be seen from comparison of examples 18 to 23, the conversion of the reaction and the overall yield of the two prepolymers both increase with increasing dimethyl carbonate, mainly because the reaction is limited by the thermodynamic equilibrium, and increasing the amount of reactants promotes the reaction in the forward direction.

As can be seen from comparison of examples 24 to 28, the conversion increases with increasing reaction temperature, but the overall yield of the two prepolymers increases and then decreases, mainly because prepolymer 1 and prepolymer 2 react further with increasing temperature to form multimers.

Comparing examples 29 to 33 and examples 34 to 38, it can be seen that the conversion increases with increasing reaction time, but the overall yield of the two prepolymers increases and then decreases, mainly because prepolymer 1 and prepolymer 2 react further with increasing temperature to form multimers.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims

1. Use of an organometallic complex as a catalyst for the synthesis of polycarbonate by transesterification;

the organic ligand is selected from any one of the following compounds:

2. use according to claim 1, characterized in that the metal cation is selected from Zn²⁺、Cu²⁺、Ni²⁺、Co²⁺、Co³⁺、Fe²⁺、Fe³⁺、Mn²⁺、Mn³⁺、Cr³⁺、Cd²⁺、Sc³⁺、Ag⁺、Pd²⁺、Pt²⁺、Ru³⁺、Ir³⁺、Rh³⁺、Zr⁴⁺、Hf⁴⁺、Li⁺、Na⁺、Be²⁺、Mg²⁺、Ca²⁺、Al³⁺、Ga³⁺、In³⁺、La³⁺、Sm³⁺、Gd³⁺、Tb³⁺、Dy³⁺、Er³⁺、Tm³⁺、Yb³⁺And Lu³⁺Any one of them.

3. Use according to claim 1, characterized in that the organometallic complex is zinc 1, 10-phenanthroline or zinc 8-hydroxyquinoline.

4. The use according to claim 1, wherein the raw materials for the synthesis of polycarbonate by transesterification are dihydroxy compounds and carbonates;

the carbonate is selected from one or a combination of at least two of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, dicyclopentyl carbonate, dicyclohexyl carbonate, bicycloheptyl carbonate and diphenyl carbonate.

5. Use according to claim 4, characterized in that the carbonate is dimethyl carbonate.

6. Use according to claim 4, characterized in that the dihydroxy compound is selected from the group consisting of bisphenol A, ethylene glycol, 1, 2-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 1, 3-hexanediol, 1, 7-heptanediol, diethylene glycol, triethylene glycol, 1, 3-cyclopentanediol, 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, 1, 10-decanediol, 2,4, 4-tetramethyl-1, 3-cyclobutanediol, isosorbide, p-xylylene glycol, tricyclodecanedimethanol, 4,4- (9-fluorene) diphenol, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 1, 6-hexanediol, 1, 3-hexanediol, 1, 7-heptanediol, isosorbide, 1, 3-cyclobutane-diol, isosorbide, p-xylylene glycol, tricyclodecanedimethanol, 4,4- (9-fluorene) diphenol, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-isobutylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3, 5-dimethylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene, 9-bis (4- (3-hydroxy-2, 2-dimethylpropoxy) phenyl) fluorene, 9-bis (6- (2-hydroxy) naphthyl) fluorene, 9-bis (5- (2-hydroxyethoxy) -1-naphthyl) fluorene, 9-bis (6- (2-hydroxyethoxy) naphthyl) fluorene, 9-bis (3-phenyl-4- (2-hydroxyethoxy) phenyl) fluorene, 9-bis (6- (2-hydroxypropoxy) naphthyl) fluorene, 2 '-bis (2-hydroxy) -1,1' -binaphthyl, 2 '-bis (2-hydroxyethoxy) -1,1' -binaphthyl, 2 '-bis (2-hydroxypropoxy) -1,1' -binaphthyl, 2,2 '-bis (2- (2-hydroxyethoxy) ethoxy) -1,1' -binaphthyl, 4'- (1-phenylethyl) bisphenol, 2-bis (4-hydroxyphenyl) butane, 4' -ethylenebiphenol, 4 '-dihydroxydiphenylmethane, 1, 3-bis [2- (4-hydroxyphenyl) -2-propyl ] benzene, 4' -dihydroxytetraphenylmethane, 2-bis (4-hydroxy-3, 5-dimethylphenyl) propane, 2-bis (4-hydroxy-3-methylphenyl) propane, and hydroquinone, or a combination of at least two thereof.

7. Use according to claim 4, characterized in that the dihydroxy compound is bisphenol A, isosorbide, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene or 1, 4-butanediol.

8. A preparation method of a polycarbonate prepolymer is characterized by comprising the following steps: taking carbonic ester and dihydroxy compound as raw materials, and reacting under the action of an organic metal complex catalyst to obtain a polycarbonate prepolymer;

the organometallic complex catalyst is selected from one or a combination of at least two of a complex of a metal cation and an organic ligand;

the organic ligand is selected from any one of the following compounds:

9. the method of claim 8, wherein the metal cation is selected from the group consisting of Zn²⁺、Cu²⁺、Ni²⁺、Co²⁺、Co³⁺、Fe²⁺、Fe³⁺、Mn²⁺、Mn³⁺、Cr³⁺、Cd²⁺、Sc³⁺、Ag⁺、Pd²⁺、Pt²⁺、Ru³⁺、Ir³⁺、Rh³⁺、Zr⁴⁺、Hf⁴⁺、Li⁺、Na⁺、Be²⁺、Mg²⁺、Ca²⁺、Al³⁺、Ga³⁺、In³⁺、La³⁺、Sm³⁺、Gd³⁺、Tb³⁺、Dy³⁺、Er³⁺、Tm³⁺、Yb³⁺And Lu³⁺Any one of them.

10. The method according to claim 8, wherein the organometallic complex catalyst is selected from zinc 1, 10-phenanthroline or zinc 8-hydroxyquinoline.

11. The method according to claim 8, wherein the carbonate is selected from one or a combination of at least two of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dipropylene carbonate, dibutyl carbonate, dibutylene carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, dicyclopentyl carbonate, dicyclohexyl carbonate, bicycloheptyl carbonate, and diphenyl carbonate.

12. The method according to claim 8, wherein the carbonate is dimethyl carbonate.

13. The method according to claim 8, wherein the dihydroxy compound is selected from the group consisting of bisphenol A, ethylene glycol, 1, 2-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 1, 3-hexanediol, 1, 7-heptanediol, diethylene glycol, triethylene glycol, 1, 3-cyclopentanediol, 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, 1, 10-decanediol, 2,4, 4-tetramethyl-1, 3-cyclobutanediol, isosorbide, p-xylylene glycol, tricyclodecanedimethanol, 4,4- (9-fluorene) diphenol, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 1, 3-hexanediol, 1, 7-heptanediol, diethylene glycol, 1, triethylene glycol, 1, 3-cyclohexanediol, 1, 4-cyclohexanediol, 4, 4-diphenol, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3, 5-dimethylphenyl) fluorene, 9-bis (4- (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene, 9-bis (4- (3-hydroxy-2, 2-dimethylpropoxy) phenyl) fluorene, 9-bis (6- (2-hydroxy) naphthyl) fluorene, 9-bis (5- (2-hydroxyethoxy) -1-naphthyl) fluorene, 9-bis (6- (2-hydroxyethoxy) naphthyl) fluorene, 9-bis (3-phenyl-4- (2-hydroxyethoxy) phenyl) fluorene, 9-bis (6- (2-hydroxypropoxy) naphthyl) fluorene, 2 '-bis (2-hydroxy) -1,1' -binaphthyl, 2 '-bis (2-hydroxyethoxy) -1,1' -binaphthyl, 2 '-bis (2-hydroxypropoxy) -1,1' -binaphthyl, 2,2 '-bis (2- (2-hydroxyethoxy) ethoxy) -1,1' -binaphthyl, 4'- (1-phenylethyl) bisphenol, 2-bis (4-hydroxyphenyl) butane, 4' -ethylenebiphenol, 4 '-dihydroxydiphenylmethane, 1, 3-bis [2- (4-hydroxyphenyl) -2-propyl ] benzene, 4' -dihydroxytetraphenylmethane, 2-bis (4-hydroxy-3, 5-dimethylphenyl) propane, 2-bis (4-hydroxy-3-methylphenyl) propane, and hydroquinone, or a combination of at least two thereof.

14. The method according to claim 8, wherein the dihydroxy compound is bisphenol A, isosorbide, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, or 1, 4-butanediol.

15. The method according to claim 8, wherein the molar ratio of the carbonate to the dihydroxy compound is 2 to 50: 1.

16. The method according to claim 8, wherein the amount of the organometallic complex used is 0.5 to 10% by mole based on the molar amount of the dihydroxy compound.

17. The method according to claim 8, wherein the amount of the organometallic complex used is 5 to 10% by mole based on the molar amount of the dihydroxy compound.

18. The method as claimed in claim 8, wherein the reaction temperature is 120-240 ℃.

19. The method as claimed in claim 8, wherein the reaction temperature is 140-200 ℃.

20. The method according to claim 8, wherein the reaction time is 0.5 to 24 hours.

21. The method according to claim 8, wherein the reaction time is 4 to 10 hours.

22. The method of claim 8, wherein the reaction is carried out under a protective atmosphere.

23. The method of claim 22, wherein the gas of the protective atmosphere is nitrogen, helium, argon, neon, or carbon dioxide.