A method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product

Abstract

The invention discloses a method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product, comprising the steps of: (1) dissolving p-toluenesulfonic acid in water; adding copper oxide and zinc oxide, heating reaction; heating and drying the product to obtain a catalyst system. (2) adding the catalyst system into an autoclave, passing high-purity nitrogen, then adding hydroquinone, propylene oxide, epichlorohydrin, passing carbon dioxide gas, heating and stirring to carry out a chemical reaction in a supercritical state; separating the catalyst from the organic phase after the reaction, purifying the organic phase, and obtaining a polycarbonate product. The present invention realizes the controllable synthesis of a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product, and has the advantages of a simple synthetic route, no need for toxic and harmful organic solvents, carbon dioxide fixation by chemical reaction, high catalyst efficiency and easy recycling, and adjustable product molecular weight, stable storage performance, and biodegradability.

Description

Technical Field

[0001] The invention relates to the technical field of polycarbonate product synthesis, in particular to a method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product. Background Art

[0002] Environment, energy and information are the cornerstones of modern civilization. Carbon emissions from the combustion of fossil energy and white pollution caused by non-degradable plastics are the most urgent problems to be solved. From the perspective of basic chemical principles and atomic economy, everything in the world is composed of more than 100 elements in the periodic table, and there is no garbage or waste. Therefore, it is theoretically feasible to selectively break a C=O double bond in the carbon dioxide molecule and convert it into ester chemicals. The technical difficulty and core are the screening and use of high-performance catalysts. On the other hand, the generation of white pollution is mainly caused by high molecular weight polyethylene, polypropylene, polystyrene and other environmentally difficult to degrade plastics, whose CC and CH chemical bonds are relatively stable and inert. It is worth noting that if high molecular weight materials containing ester bonds such as polycarbonate and polyurethane are used, they can not only meet the daily needs of human beings, but also be degraded and reused under certain conditions with the help of acid or base catalysts, and can be degraded even in natural environments. Therefore, based on the above content, converting a large amount of low-value-added carbon dioxide currently discharged by industry into a huge amount of polyester materials has significant environmental benefits and economic value.

[0003] There are some literature and product reports on the resource utilization of carbon dioxide, mainly focusing on physical and chemical utilization. In terms of physical application, such as as carbonated beverages or foaming agents, carbon dioxide can still be directly discharged into the natural environment because it does not involve chemical reactions. In terms of chemical utilization, it can be converted into N,N-dimethylformamide, N,N-dimethylacetamide, methanol, propylene carbonate, ethylene carbonate, polycarbonate polyols, etc., but the current output is not large, and many are in the pilot or demonstration production stage, mainly due to problems in catalyst production technology and product synthesis costs. Among them, carbon dioxide and propylene oxide are polymerized to synthesize polycarbonate polyols PPC, but large-scale industrial production has not been achieved. Therefore, the reaction system needs to be improved and optimized before large-scale production can be achieved. In addition, many organic reactions need to be carried out in organic solvents, and volatile organic pollutants are easily generated during use and leaked into the environment. After the reaction, they need to be removed, and the separation process accounts for nearly 70% of all energy consumption in the synthesis process. The supercritical state that has gradually emerged in recent years is expected to solve these problems. The critical temperature and pressure of carbon dioxide are 31.1°C and 7.38MPa respectively, which are relatively easy to achieve in laboratories and chemical companies. Therefore, if this technology can be applied to organic synthesis, especially the polymerization reaction of carbon dioxide and epoxy substances, it will have good price advantages and application prospects.

[0004] In addition to the above-mentioned biodegradable fatty chain polycarbonate polyols under development, aromatic polycarbonate materials have good mechanical strength and wear resistance due to the presence of rigid structures such as benzene rings, and can be used in engineering or special functional materials. If the two are combined, rigid benzene ring groups and flexible polyether groups are grafted into the molecular structure at the same time through chemical reactions, and the molecular structure also contains ester bonds with greater polarity, it is expected that a new type of biodegradable material with special uses will be obtained. At present, there are few research reports in this area, which deserves the attention of more scientific and technological workers. Summary of the invention

[0005] The object of the present invention is to provide a method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product, using a catalyst containing an organic ligand and a bimetallic ion, and molecularly splicing carbon dioxide molecules with hydroquinone and epoxy compounds (propylene oxide / epichlorohydrin) under relatively mild conditions to obtain a polycarbonate product containing rigid and flexible structural units that is degradable in the natural environment. This technology can recycle relatively inert carbon dioxide molecules, and the process route is simple, without organic solvents, the product hydroxyl value and viscosity and other properties can be adjusted, and the carbon dioxide fixation rate is high. It is expected to play its own unique advantages in the field of new chemical materials and help achieve my country's carbon peak and carbon neutrality goals.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product comprises the following two steps:

[0008] (1) Preparation of the catalyst: dissolving p-toluenesulfonic acid in water; adding copper oxide and zinc oxide in batches and heating for reaction; heating and drying the reaction product to obtain a catalyst system;

[0009] (2) Synthesis of aromatic ring-aliphatic chain composite polycarbonate products: The above catalyst system is added to a high-pressure reactor, and high-purity nitrogen is introduced into the reactor to remove the air in the system. Hydroquinone, propylene oxide, and epichlorohydrin are then added, and finally carbon dioxide gas is introduced. The mixture is heated and stirred to carry out a chemical reaction in a supercritical state. After the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, and the mixture in the reactor is removed. The upper organic matter and the lower catalyst are separated by phase separation, and the lower catalyst is recovered. After washing and drying with dichloromethane, it can be reused for the next catalytic reaction. Saturated sodium bicarbonate solution is added to the upper organic matter for treatment, and the mixture is allowed to stand. Then, phase separation is carried out, and water and small molecular by-products in the organic phase are removed by reduced pressure distillation to obtain a colorless, transparent to light yellow polycarbonate product.

[0010] During the catalyst synthesis process, the molar ratio of copper oxide to zinc oxide was 3:1, and the molar ratio of the two oxides to p-toluenesulfonic acid was 1:2.05; the reaction temperature was 50°C and the time was 1h; the drying temperature was 110°C and the time was 2h.

[0011] In step (2), the hydroquinone is at least one of p-diphenol, o-diphenol and m-diphenol; the molar ratio of hydroquinone, propylene oxide and epichlorohydrin is 1:(10-100):(1-10); after the introduction of carbon dioxide, the system pressure is 7.5-10.0 MPa, which is a supercritical state; the amount of catalyst used is 1‰ of the total mass of hydroquinone, propylene oxide and epichlorohydrin.

[0012] In step (2), the reaction temperature of the polycarbonate product synthesis is 80-150°C, and the reaction time is 4-10 hours; the vacuum distillation temperature is 110°C, and the time is 2 hours; after the synthesis reaction is completed, the mixture removed from the kettle is adjusted to a pH value of 7-9 using a sodium bicarbonate solution, and then phase separation is performed. The carbon dioxide-based aromatic ring-fat chain composite polycarbonate product has a hydroxyl functionality of 2, a hydroxyl value of 17.1-141 mgKOH / g, and a carbon dioxide molar fixed amount of 11.4-18.2%.

[0013] The beneficial effects of the present invention are:

[0014] (1) The catalyst containing organic ligands and bimetallic ions is used, the raw material price is low, the synthesis route is simple, and it can be recycled and reused;

[0015] (2) Supercritical carbon dioxide is used for dissolution and reaction without adding organic solvents;

[0016] (3) The obtained polycarbonate product contains rigid benzene ring groups, flexible polyether groups, ester bonds that are degradable in the natural environment, and chlorine elements with flame retardant properties. It has a high carbon dioxide fixation capacity, and the product has price advantages and environmental benefits. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with specific implementation modes.

[0018] Preparation of catalyst suitable for synthesizing carbon dioxide-based aromatic ring-aliphatic chain composite polycarbonate products

[0019] Example 1

[0020] Water and p-toluenesulfonic acid in a mass ratio of 1:1 are mixed and stirred to dissolve; copper oxide and zinc oxide are added in batches, heated and the system is allowed to fully react chemically, the molar ratio of copper oxide to zinc oxide is 3:1, and the molar ratio of the oxides of the two (i.e., the combination of copper oxide and zinc oxide) to p-toluenesulfonic acid is 1:2.05; the reaction temperature is 50°C and the reaction time is 1 hour; after the reaction, the reaction is heated and dried (the drying temperature is 110°C and the time is 2 hours) to obtain a catalyst system.

[0021] Synthesis of CO2-based aromatic ring-aliphatic chain composite polycarbonate products

[0022] Example 2

[0023] The catalyst system prepared in Example 1 is added to a high-pressure reactor, high-purity nitrogen is introduced into the reactor to remove the air in the system, and then 1 mol of p-diphenol, 10 mol of propylene oxide and 1 mol of epichlorohydrin are added, the catalyst dosage is 1‰ of the total mass of p-diphenol, propylene oxide and epichlorohydrin, and finally carbon dioxide gas is introduced, and the chemical reaction in a supercritical state is carried out under heating and stirring, the reaction pressure is 7.5 MPa, the temperature is 80°C, and the reaction time is 10 h; after the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, the mixture in the reactor is removed, the pH value is adjusted to 7 with sodium bicarbonate solution, and then the upper organic matter and the lower catalyst are separated by phase separation; the catalyst in the lower layer is recovered, washed with dichloromethane, dried and stored for standby; a saturated sodium bicarbonate solution is added to the upper organic matter for treatment, allowed to stand, and then phase separation is carried out, and then the moisture and small molecule by-products in the organic phase are removed by reduced pressure distillation at 110°C for 2h to obtain a colorless, transparent to light yellow polycarbonate product.

[0024] Example 3

[0025] The catalyst system prepared in Example 1 is added to a high-pressure reactor, high-purity nitrogen is introduced into the reactor to remove the air in the system, and then 1 mol of p-diphenol, 10 mol of propylene oxide and 1 mol of epichlorohydrin are added, the catalyst amount is 1‰ of the total mass of p-diphenol, propylene oxide and epichlorohydrin, and finally carbon dioxide gas is introduced, and the chemical reaction in a supercritical state is carried out under heating and stirring, the reaction pressure is 10.0 MPa, the temperature is 150°C, and the reaction time is 4h; after the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, the mixture in the reactor is removed, the pH value is adjusted to 7-9 with sodium bicarbonate solution, and then the upper organic matter and the lower catalyst are separated by phase separation; the catalyst in the lower layer is recovered, washed with dichloromethane, dried and stored for standby; a saturated sodium bicarbonate solution is added to the upper organic matter for treatment, allowed to stand, and then phase separation is carried out, and then the moisture and small molecule by-products in the organic phase are removed by reduced pressure distillation at 110°C for 2h to obtain a colorless, transparent to light yellow polycarbonate product.

[0026] Example 4

[0027] The catalyst system is added into a high-pressure reactor, high-purity nitrogen is introduced into the reactor to remove the air in the system, and then 1 mol of p-diphenol, 100 mol of propylene oxide and 10 mol of epichlorohydrin are added, the amount of the catalyst is 1‰ of the total mass of p-diphenol, propylene oxide and epichlorohydrin, and finally carbon dioxide gas is introduced, and the chemical reaction in a supercritical state is carried out under heating and stirring, the reaction pressure is 7.5 MPa, the temperature is 80°C, and the reaction time is 10 hours; after the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, the mixture in the reactor is removed, the pH value is adjusted to 7-9 with sodium bicarbonate solution, and then the upper organic matter and the lower catalyst are separated by phase separation; the lower catalyst is recovered, washed with dichloromethane, dried and stored for standby; saturated sodium bicarbonate solution is added to the upper organic matter for treatment, allowed to stand, and then phase separation is carried out, and then water and small molecular by-products in the organic phase are removed by reduced pressure distillation at 110°C for 2 hours to obtain a colorless, transparent to light yellow polycarbonate product.

[0028] Example 5

[0029] The catalyst system prepared in Example 1 is added to a high-pressure reactor, high-purity nitrogen is introduced into the reactor to remove the air in the system, and then 1 mol of p-diphenol, 100 mol of propylene oxide and 1 mol of epichlorohydrin are added, the catalyst amount is 1‰ of the total mass of p-diphenol, propylene oxide and epichlorohydrin, and finally carbon dioxide gas is introduced, and the chemical reaction in a supercritical state is carried out under heating and stirring, the pressure is 10.0 MPa, the temperature is 150°C, and the reaction time is 4h; after the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, the mixture in the reactor is removed, the pH value is adjusted to 7-9 with sodium bicarbonate solution, and then the upper organic matter and the lower catalyst are separated by phase separation; the catalyst in the lower layer is recovered, washed with dichloromethane, dried and stored for standby; a saturated sodium bicarbonate solution is added to the upper organic matter for treatment, allowed to stand, and then phase separation is carried out, and then the moisture and small molecule by-products in the organic phase are removed by reduced pressure distillation at 110°C for 2h to obtain a colorless, transparent to light yellow polycarbonate product.

[0030] Example 6

[0031] The catalyst system prepared in Example 1 is added to a high-pressure reactor, high-purity nitrogen is introduced into the reactor to remove the air in the system, and then 1 mol of p-diphenol, 40 mol of propylene oxide and 5 mol of epichlorohydrin are added, the catalyst amount is 1‰ of the total mass of p-diphenol, propylene oxide and epichlorohydrin, and finally carbon dioxide gas is introduced, and the chemical reaction in a supercritical state is carried out under heating and stirring, the pressure is 8.5 MPa, the temperature is 130°C, and the reaction time is 6 hours; after the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, the mixture in the reactor is removed, the pH value is adjusted to 7-9 with sodium bicarbonate solution, and then the catalyst in the lower layer is recovered through phase separation, washed with dichloromethane, dried and stored for standby; saturated sodium bicarbonate solution is added to the upper organic matter for treatment, allowed to stand, and then phase separation is carried out, and then water and small molecule by-products in the organic phase are removed by reduced pressure distillation at 110°C for 2 hours to obtain a colorless, transparent to light yellow polycarbonate product.

[0032] Example 7

[0033] The catalyst system prepared in Example 1 is added to a high-pressure reactor, high-purity nitrogen is introduced into the reactor to remove the air in the system, and then 1 mol of p-diphenol, 80 mol of propylene oxide, and 7 mol of epichlorohydrin are added, the catalyst dosage is 1‰ of the total mass of p-diphenol, propylene oxide, and epichlorohydrin, and finally carbon dioxide gas is introduced, and the chemical reaction in a supercritical state is carried out under heating and stirring, the pressure is 9.0 MPa, the temperature is 90°C, and the reaction time is 9h; after the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, the mixture in the reactor is removed, the pH value is adjusted to 7-9 with sodium bicarbonate solution, and then the catalyst in the lower layer is recovered through phase separation, washed with dichloromethane, dried, and stored for standby use; saturated sodium bicarbonate solution is added to the upper organic matter for treatment, allowed to stand, and then phase separation is carried out, and then water and small molecule by-products in the organic phase are removed by reduced pressure distillation at 110°C for 2h to obtain a colorless, transparent to light yellow polycarbonate product.

[0034] The carbon dioxide-based aromatic ring-fat chain composite polycarbonate products synthesized in the above Examples 2 to 7 were analyzed and tested, and the test results are shown in Table 1 (the biodegradation rate was subjected to natural degradation experiments according to the national standard GB / T20197-2006). According to the molecular weight and hydroxyl value, this type of polycarbonate product was polymerized with isocyanate MDI by chemical reaction with equal functionality, and the obtained polyurethane foam material had a certain flame retardant effect, and the oxygen index was shown in Table 1. As can be seen from Table 1, the polycarbonate product synthesized by the content of the present invention has a hydroxyl value, viscosity and molecular weight that can be reasonably regulated within a certain range, and the fixed amount of cheap and inert carbon dioxide molecules is also high, which has good environmental benefits and economic value.

[0035] Table 1: Test results of polycarbonate products and foaming

[0036]

[0037] In Examples 2 to 7, an equal amount of p-diphenol can be replaced by o-diphenol or m-diphenol or a mixture of at least two of p-diphenol, o-diphenol and m-diphenol to synthesize a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product. It was found that the product had a hydroxyl functionality of 2, a hydroxyl value of 17.3 to 140 mgKOH / g, a carbon dioxide molar fixed amount of 11.5 to 18%, and an oxygen index of the polyurethane obtained by foaming was between 24.9 and 29.1.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product, characterized in that: It includes the following two steps: (1) Preparation of the catalyst: dissolving p-toluenesulfonic acid in water; adding copper oxide and zinc oxide in batches and heating for reaction; heating and drying the reaction product to obtain a catalyst system; (2) Synthesis of aromatic ring-aliphatic chain composite polycarbonate products: The above catalyst system is added to a high-pressure reactor, and high-purity nitrogen is introduced to remove the air in the system. Hydroquinone, propylene oxide, and epichlorohydrin are then added, and finally carbon dioxide gas is introduced. The mixture is heated and stirred to carry out a chemical reaction in a supercritical state. After the reaction is completed, the temperature is lowered, the tail gas is discharged and collected, and the mixture in the reactor is removed. The upper organic matter and the lower catalyst are separated by phase separation, and the lower catalyst is recovered. After washing and drying with dichloromethane, it can be reused for the next catalytic reaction. Saturated sodium bicarbonate solution is added to the upper organic matter for treatment, and the mixture is allowed to stand, and then phase separation is carried out. Water and small molecular by-products in the organic phase are removed by reduced pressure distillation to obtain a colorless, transparent to light yellow polycarbonate product.

2. A method for synthesizing a carbon dioxide-based aromatic ring-aliphatic chain composite polycarbonate product as claimed in claim 1, characterized in that: During the catalyst synthesis process, the molar ratio of copper oxide to zinc oxide was 3:1, and the molar ratio of the two oxides to p-toluenesulfonic acid was 1:2.05; the reaction temperature was 50°C and the reaction time was 1 h.

3. The method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product as claimed in claim 1, characterized in that: In step (1), the drying temperature of the catalyst is 110° C. and the drying time is 2 h.

4. The method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product as claimed in claim 1, characterized in that: In step (2), the hydroquinone is at least one of p-diphenol, o-diphenol and m-diphenol; the molar ratio of hydroquinone, propylene oxide and epichlorohydrin is 1:(10-100):(1-10); and the amount of catalyst used is 1‰ of the total mass of hydroquinone, propylene oxide and epichlorohydrin.

5. The method for synthesizing a carbon dioxide-based aromatic ring-fat chain composite polycarbonate product as claimed in claim 1, characterized in that: In step (2), after the introduction of carbon dioxide, the system pressure is 7.5-10.0 MPa, which is a supercritical state.

6. The method for synthesizing a carbon dioxide-based aromatic ring-aliphatic chain composite polycarbonate product as claimed in claim 1, characterized in that: In step (2), the reaction temperature for synthesizing the polycarbonate product is 80 to 150° C., and the reaction time is 4 to 10 hours.

7. The method for synthesizing a carbon dioxide-based aromatic ring-aliphatic chain composite polycarbonate product as claimed in claim 1, characterized in that: In step (2), after the synthesis reaction is completed, the mixture removed from the kettle is adjusted to a pH value of 7 to 9 using a sodium bicarbonate solution, and then phase separation is performed; the reduced pressure distillation temperature is 110° C. and the time is 2 h.

8. The method for synthesizing a carbon dioxide-based aromatic ring-aliphatic chain composite polycarbonate product as claimed in claim 1, characterized in that: The carbon dioxide-based aromatic ring-fat chain composite polycarbonate product has a hydroxyl functionality of 2, a hydroxyl value of 17.1-141 mgKOH / g, and a carbon dioxide molar fixed amount of 11.4-18.2%.

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