Rare earth element doped titanium dioxide nanoparticle catalyst as well as preparation method and application thereof
By using different rare earth elements to dopant titanium dioxide nanoparticles as catalysts, the existing polyester catalysts are solved, and efficient and environmentally friendly polyester preparation is achieved, suitable for food and biomedical materials.
Patent Information
- Application Number
- CN202311765105.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-20
- Publication Date
- 2025-06-20
AI Technical Summary
Among the existing polyester catalysts, lead, antimony and tin catalysts are toxic and are not suitable for use in food materials and biomedical materials. Although titanium catalysts are environmentally friendly, their catalytic performance is average in the esterification stage.
The nanoparticles doped with different rare earth elements are used as catalysts, and the nanoparticle catalyst is formed by doping rare earth elements such as lanthanum, cerium, neodymium, etc. with titanium dioxide, which is used for the efficient preparation of polyester.
It improves the activity, selectivity and stability of the catalyst, promotes the growth of polymer chains, reduces the occurrence of side reactions, and reduces environmental pollution, and is suitable for the production of food materials and biomedical materials.
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Figure CN120173219A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a rare earth element-doped titanium dioxide nanoparticle catalyst, a preparation method and an application thereof, belonging to the technical field of polyester synthesis. Background Art
[0002] At present, the commonly used methods for preparing polyesters include direct esterification method, transesterification method, ring-opening polymerization method, solution polymerization method, and the catalysts used are generally lead-based, antimony-based, tin-based and titanium-based catalysts. Lead-based, antimony-based and tin-based catalysts are toxic and not conducive to environmental protection requirements, and are not suitable for use in food materials and biomedical materials. Titanium metal resources are rich, harmless to the environment and human body. Titanium dioxide has the advantages of good stability, low cost, non-toxicity, and no pollution to the environment.
[0003] In recent years, many scholars at home and abroad have used titanium-based catalysts in combination with other metal or non-metal elements, allegedly to achieve the purpose of improving catalytic performance and enhancing product hue. Generally, the catalytic effect of titanium-based catalysts in the esterification stage is average, and the addition of rare earth elements can shorten the reaction time in the esterification stage to a certain extent. Rare earth and titanium dioxide have a synergistic effect, and the synthesized polyester has more excellent thermal stability. In recent years, people have been exploring safe, reliable and highly catalytic active catalysts for synthesizing polyesters. Summary of the Invention
[0004] In view of this, the technical problem to be solved by the present invention is to provide a method for efficiently catalyzing the preparation of polyesters based on different rare earth element-doped titanium dioxide nanoparticles. The present invention uses a specific catalyst to prepare biobased polyesters with high catalytic efficiency, safety and environmental protection.
[0005] Different rare earth element-doped titanium dioxide catalysts have high activity, high selectivity, high stability, promote the growth of polymer chains, reduce the occurrence of side reactions, and at the same time can reduce environmental pollution problems caused by volatilization.
[0006] According to one aspect of the present application, there is provided a rare earth element-doped titanium dioxide nanoparticle catalyst, wherein the rare earth element-doped titanium dioxide nanoparticle catalyst comprises titanium dioxide and a rare earth element doped in the titanium dioxide;
[0007] The rare earth element is selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium;
[0008] The diameter of the rare earth element-doped titanium dioxide nanoparticle catalyst is 1-100 nm.
[0009] Optionally, the diameter of the rare earth element-doped titanium dioxide nanoparticle catalyst is independently selected from any value of 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm or a range value between any two of the above.
[0010] Optionally, the doping amount of the rare earth element in the rare earth element-doped titanium dioxide nanoparticle catalyst is 0.09 wt% to 20 wt%.
[0011] According to another aspect of the present application, a preparation method of the above-mentioned rare earth element-doped titanium dioxide nanoparticle catalyst is provided, and the preparation method includes:
[0012] Reacting, drying, and calcining a mixture containing a titanium salt, a rare earth element salt, citric acid, ethylenediamine, ethanol, and hydrofluoric acid to obtain the rare earth element-doped titanium dioxide nanoparticle catalyst.
[0013] Optionally, the titanium salt is selected from at least one of titanium sulfate, titanium chloride, titanium tetrachloride, titanium oxysulfate, tetrabutyl titanate, and tetraisopropyl titanate.
[0014] Optionally, the rare earth element salt is selected from at least one of a chloride salt, a nitrate salt, and a sulfate salt containing a rare earth element.
[0015] Optionally, the gadolinium source accounts for 0.01% to 2% of the molar amount of the titanium source.
[0016] Optionally, the molar ratio of the titanium source, citric acid, ethylenediamine, absolute ethanol, and hydrofluoric acid is: (0.0005 to 0.002): (0.002 to 0.004): (0.1 to 0.15): (0.13 to 0.18): (0.008 to 0.01).
[0017] Optionally, the temperature of the reaction is 100 to 200 °C, and the time of the reaction is 1 to 10 h.
[0018] Optionally, the temperature of the reaction is independently selected from any value of 100 °C, 120 °C, 130 °C, 140 °C, 160 °C, 170 °C, 180 °C, 200 °C or a range value between any two of the above.
[0019] Optionally, the time of the reaction is independently selected from any value of 1 h, 3 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h or a range value between any two of the above.
[0020] Optionally, the temperature of the drying is 30 to 80 °C, and the time of the drying is 3 to 15 h.
[0021] Optionally, the drying temperature is independently selected from any value of 30°C, 50°C, 60°C, 80°C or a range value between any two of the above.
[0022] Optionally, the drying time is independently selected from any value of 3 h, 5 h, 6 h, 8 h, 9 h, 10 h, 12 h, 13 h, 15 h or a range value between any two of the above.
[0023] Optionally, the calcination temperature is 300 - 600°C and the calcination time is 3 - 10 h.
[0024] Optionally, the calcination temperature is independently selected from any value of 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C or a range value between any two of the above.
[0025] Optionally, the calcination time is independently selected from any value of 3 h, 4 h, 6 h, 8 h, 9 h, 10 h or a range value between any two of the above.
[0026] According to another aspect of the present application, a method for preparing a polyester is provided, and the preparation method includes:
[0027] (1) Under an inert atmosphere, reacting a mixture containing a dibasic acid, a diol, and a catalyst in Reaction I to obtain a prepolymer;
[0028] (2) Reacting the prepolymer in Reaction II to obtain the polyester;
[0029] The catalyst is selected from the above-mentioned rare earth element-doped titanium dioxide nanoparticle catalyst.
[0030] Optionally, the dibasic acid is selected from at least one of 1,4-succinic acid, 1,3-succinic acid, 1,5-glutaric acid, 3,4-furandicarboxylic acid, 3,4-thiophenedicarboxylic acid, 1,6-adipic acid, oxalic acid, malonic acid, 1,7-pimelic acid, 1,8-suberic acid, terephthalic acid, isophthalic acid, 1,9-nonanedicarboxylic acid, 1,10-sebacic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 2,5-thiophenedicarboxylic acid, 2,4-thiophenedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 2,4-furandicarboxylic acid, 2,6-naphthalenedicarboxylic acid.
[0031] Optionally, the diol is selected from at least one of ethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,8-octanediol, 1,9-nonanediol, 2,3-butanediol, 1,5-pentanediol, 1,7-heptanediol, 1,10-decanediol, 1,2-propanediol, 1,6-hexanediol, isosorbide, 1,4-butanediol, 1,4-cyclohexanediol, 1,3-cyclobutanedimethanol, 1,4-cyclohexanedimethanol, polyethylene glycol.
[0032] Optionally, the dosage of the rare earth element-doped titanium dioxide nanoparticle catalyst is 0.01 to 2% of the molar amount of the dibasic acid.
[0033] Optionally, the dosage of the rare earth element-doped titanium dioxide nanoparticle catalyst is independently selected from any value of 0.01%, 0.05%, 0.1%, 1%, 1.5%, 2% of the molar amount of the dibasic acid or the range value between any two of the above.
[0034] Optionally, the molar ratio of the diol to the dibasic acid is 1 to 3:1.
[0035] Optionally, in the step (1), the temperature of the reaction I is 100 to 250 °C, and the time of the reaction I is 0.5 to 5 h.
[0036] Optionally, the inert atmosphere is selected from at least one of nitrogen, helium, neon or argon.
[0037] Optionally, in the step (2), the pressure of the reaction II is 10 to 110 Pa.
[0038] Optionally, in the step (2), the temperature of the reaction II is 120 to 300 °C, and the time of the reaction II is 0.5 to 10 h.
[0039] As an optional embodiment, the present application is realized by the following technical solutions:
[0040] In the present application, the method for preparing a polyester using the rare earth element-doped titanium dioxide nanoparticle catalyst includes the following steps:
[0041] (1) Dissolve titanium sulfate and citric acid in deionized water.
[0042] (2) Add ethylenediamine, rare earth element solution, absolute ethanol, and hydrofluoric acid in sequence under 50 rpm to 300 rpm and stir for 10 min to 60 min.
[0043] (3) Transfer to a reaction kettle and react at 100 to 200 °C for 1 h to 10 h, and take out after cooling to room temperature.
[0044] (4) Wash the precipitate at the bottom of the reaction kettle with deionized water and absolute ethanol alternately for 2 to 10 times.
[0045] (5) Send it into a vacuum drying oven at 30 °C to 80 °C and dry for 3 h to 15 h. Grind the dried product and calcine it in a muffle furnace at 300 °C to 600 °C for 3 h to 10 h, and take out and grind it to obtain different rare earth-doped titanium dioxide nanoparticle catalysts.
[0046] The present invention provides a method for preparing polyester using titanium dioxide nanoparticles doped with different rare earth elements as a catalyst, and the method comprises the following steps:
[0047] A) Under nitrogen protection, one or more of a diol and a diacid are subjected to an esterification reaction catalyzed by a titanium dioxide nanoparticle catalyst doped with different rare earth elements to obtain a prepolymer;
[0048] B) The prepolymer is subjected to a polycondensation reaction to obtain a polyester.
[0049] The beneficial effects that can be achieved by this application include:
[0050] The present invention uses titanium dioxide doped with different rare earth elements as a nanoparticle catalyst for synthesizing polyester. The titanium dioxide nanoparticle catalyst doped with different rare earth elements has a large specific surface area. A small amount of rare earth doping can improve the catalytic activity of titanium dioxide. The polyester has a high molecular weight and a low ether bond content, reducing the occurrence of side reactions. At the same time, it can reduce the environmental pollution problems caused by volatilization. Importantly, the titanium dioxide nanoparticle catalyst doped with different rare earth elements used has good thermal stability and high catalytic efficiency. Description of the Drawings
[0051] Figure 1 It is the electron microscope image of the gadolinium-doped titanium dioxide catalyst in Preparation Example 1 of this application, and the scale bar is 1 μm.
[0052] Figure 2 It is the electron microscope image of the cerium-doped titanium dioxide catalyst in Preparation Example 2 of this application, and the scale bar is 1 μm.
[0053] Figure 3 It is the electron microscope image of the europium-doped titanium dioxide catalyst in Preparation Example 3 of this application, and the scale bar is 1 μm.
[0054] Figure 4 It is the electron microscope image of the yttrium-doped titanium dioxide catalyst in Preparation Example 4 of this application, and the scale bar is 1 μm.
[0055] Figure 5 It is the electron microscope image of the lanthanum-doped titanium dioxide catalyst in Preparation Example 5 of this application, and the scale bar is 1 μm. Detailed Embodiments
[0056] The following describes this application in detail with reference to the embodiments, but this application is not limited to these embodiments.
[0057] Unless otherwise specified, the raw materials in the embodiments of this application are all purchased through commercial channels.
[0058] This application uses a field emission scanning electron microscope (JFM-7800F) to characterize the gadolinium rare earth-doped titanium dioxide catalyst.
[0059] The relative viscosity was detected using an Ubbelohde viscometer. The detection conditions were as follows: an Ubbelohde viscometer with a capillary inner diameter of 0.84 mm was used for determination, the temperature was (25 ± 0.1) °C, and the solvent was a mixed solution of phenol and tetrachloroethane with a mass ratio of 1:1.
[0060] Preparation Example 1: Gadolinium-doped titanium dioxide nanoparticle catalyst
[0061] (1) Dissolve 0.24 g of titanium sulfate and 0.63 g of citric acid in deionized water.
[0062] (2) Sequentially add 9 ml of ethylenediamine, 5 - 100 μL of gadolinium element solution, 10 ml of absolute ethanol, and 1.35 ml of hydrofluoric acid, and stir for 10 min - 60 min at 50 rpm - 300 rpm.
[0063] (3) Transfer to a reaction kettle and react at 100 - 200 °C for 1 h - 10 h, then cool to room temperature and take out.
[0064] (4) Wash the precipitate at the bottom of the reaction kettle alternately with deionized water and absolute ethanol for 2 - 10 times.
[0065] (5) Place it in a vacuum drying oven at 30 °C - 80 °C and dry for 3 h - 15 h. Grind the dried product and calcine it in a muffle furnace at 300 °C - 600 °C for 3 h - 10 h. Take it out and grind it to obtain a gadolinium element-doped titanium dioxide nanoparticle catalyst with a particle size of 1 - 100 nm. As Figure 1 shown, it can be seen from Figure 1 that the gadolinium-doped titanium dioxide nanoparticle catalyst was successfully prepared.
[0066] Preparation Example 2: Cerium-doped titanium dioxide nanoparticle catalyst as a catalyst
[0067] (1) Dissolve 0.24 g of titanium sulfate and 0.63 g of citric acid in deionized water.
[0068] (2) Sequentially add 9 ml of ethylenediamine, 5 - 100 μL of cerium element solution, 10 ml of absolute ethanol, and 1.35 ml of hydrofluoric acid, and stir for 10 min - 60 min at 50 rpm - 300 rpm.
[0069] (3) Transfer to a reaction kettle and react at 100 - 200 °C for 1 h - 10 h, then cool to room temperature and take out.
[0070] (4) Wash the precipitate at the bottom of the reaction kettle alternately with deionized water and absolute ethanol for 2 - 10 times.
[0071] (5) Transfer it to a vacuum drying oven at 30°C to 80°C and dry for 3 h to 15 h. Grind the dried product and calcine it in a muffle furnace at 300°C to 600°C for 3 h to 10 h. After taking it out, grind it to obtain a cerium element-doped titanium dioxide nanoparticle catalyst with a particle size of 1 to 100 nm. As Figure 2 shown, it can be seen from Figure 2 that the cerium-doped titanium dioxide nanoparticle catalyst is successfully prepared.
[0072] Preparation Example 3 Europium-doped titanium dioxide nanoparticle catalyst as a catalyst
[0073] (1) Dissolve 0.24 g of titanium sulfate and 0.63 g of citric acid in deionized water.
[0074] (2) Add 9 ml of ethylenediamine, 5 to 100 μL of europium element solution, 10 ml of absolute ethanol, and 1.35 ml of hydrofluoric acid in sequence under 50 rpm to 300 rpm and stir for 10 min to 60 min.
[0075] (3) Transfer it to a reaction kettle and react at 100 to 200°C for 1 h to 10 h, then cool to room temperature and take it out.
[0076] (4) Wash the precipitate at the bottom of the reaction kettle with deionized water and absolute ethanol alternately for 2 to 10 times.
[0077] (5) Transfer it to a vacuum drying oven at 30°C to 80°C and dry for 3 h to 15 h. Grind the dried product and calcine it in a muffle furnace at 300°C to 600°C for 3 h to 10 h. After taking it out, grind it to obtain a europium element-doped titanium dioxide nanoparticle catalyst with a particle size of 1 to 100 nm. As Figure 3 shown, it can be seen from Figure 3 that the europium-doped titanium dioxide nanoparticle catalyst is successfully prepared.
[0078] Preparation Example 4 Yttrium-doped titanium dioxide nanoparticle catalyst as a catalyst
[0079] (1) Dissolve 0.24 g of titanium sulfate and 0.63 g of citric acid in deionized water.
[0080] (2) Add 9 ml of ethylenediamine, 5 to 100 μL of yttrium element solution, 10 ml of absolute ethanol, and 1.35 ml of hydrofluoric acid in sequence under 50 rpm to 300 rpm and stir for 10 min to 60 min.
[0081] (3) Transfer it to a reaction kettle and react at 100 to 200°C for 1 h to 10 h, then cool to room temperature and take it out.
[0082] (4) Wash the precipitate at the bottom of the reaction kettle with deionized water and absolute ethanol alternately for 2 to 10 times.
[0083] (5) Feed it into a vacuum drying oven at 30°C to 80°C for drying for 3h to 15h. After grinding the dried product, calcine it in a muffle furnace at 300°C to 600°C for 3h to 10h. After taking it out and grinding, yttrium-doped titanium dioxide nanoparticles catalyst is obtained, with a particle size of 1 to 100 nm. As Figure 4 shown, it can be seen from Figure 4 that the yttrium-doped titanium dioxide nanoparticles catalyst is successfully prepared.
[0084] Using the lanthanum-doped titanium dioxide nanoparticles catalyst prepared in Preparation Example 5 as the catalyst
[0085] (1) Dissolve 0.24 g of titanium sulfate and 0.63 g of citric acid in deionized water.
[0086] (2) Add 9 ml of ethylenediamine, 5 to 100 μL of scandium element solution, 10 ml of absolute ethanol, and 1.35 ml of hydrofluoric acid in sequence under 50 rpm to 300 rpm and stir for 10 min to 60 min.
[0087] (3) Transfer it to a reaction kettle and react at 100 to 200°C for 1h to 10h, and take it out after cooling to room temperature.
[0088] (4) Wash the precipitate at the bottom of the reaction kettle with deionized water and absolute ethanol alternately for 2 to 10 times.
[0089] (5) Feed it into a vacuum drying oven at 30°C to 80°C for drying for 3h to 15h. After grinding the dried product, calcine it in a muffle furnace at 300°C to 600°C for 3h to 10h. After taking it out and grinding, lanthanum-doped titanium dioxide nanoparticles catalyst is obtained, with a particle size of 1 to 100 nm. As Figure 5 shown, it can be seen from Figure 5 that the scandium-doped titanium dioxide nanoparticles catalyst is successfully prepared.
[0090] Example 1
[0091] Add 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.0 mol of ethylene glycol into a reaction flask. Using the gadolinium-doped titanium dioxide nanoparticles catalyst as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, stir and react at 170°C for 1h, at 180°C for 1h, at 190°C for 1h, and at 210°C for 2.5h to generate a prepolymer;
[0092] (2) Vacuum the above prepolymer to 107.6 Pa and stir and react at 240°C for 4h to finally obtain polyethylene naphthalate, and the inherent viscosity is measured to be 0.68 dL / g.
[0093] Example 2
[0094] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and gadolinium-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 0.01% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0095] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.66 dL / g.
[0096] Example 3
[0097] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and gadolinium-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0098] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.75 dL / g.
[0099] Example 4
[0100] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and gadolinium-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 2% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0101] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.69 dL / g.
[0102] Example 5
[0103] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and cerium-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0104] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.77 dL / g.
[0105] Example 6
[0106] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and a europium-doped titanium dioxide nanoparticle catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, 180 °C for 1 h, 190 °C for 1 h, and 210 °C for 2.5 h to form a prepolymer;
[0107] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.79 dL / g.
[0108] Example 7
[0109] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and a yttrium-doped titanium dioxide nanoparticle catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, 180 °C for 1 h, 190 °C for 1 h, and 210 °C for 2.5 h to form a prepolymer;
[0110] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.76 dL / g.
[0111] Example 8
[0112] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and a lanthanum-doped titanium dioxide nanoparticle catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, 180 °C for 1 h, 190 °C for 1 h, and 210 °C for 2.5 h to form a prepolymer;
[0113] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene 2,5-furandicarboxylate, and the inherent viscosity was measured to be 0.75 dL / g.
[0114] Example 9
[0115] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 2.0 mol of ethylene glycol were added to a reaction flask, and lanthanum-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0116] The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.73 dL / g.
[0117] Example 10
[0118] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 3.0 mol of ethylene glycol were added to a reaction flask, and lanthanum-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0119] The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.70 dL / g.
[0120] Example 11
[0121] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 3.0 mol of ethylene glycol were added to a reaction flask, and gadolinium-doped titanium dioxide nanoparticles catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0122] (2) The above prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h to finally obtain polyethylene naphthalate, and the inherent viscosity was measured to be 0.71 dL / g.
[0123] Example 12
[0124] 1.0 mol of 2,5-furandicarboxylic acid and 3.0 mol of 1,3-butanediol were added to a reaction flask, and gadolinium-doped titanium dioxide catalyst was used as the catalyst, accounting for 0.1% of the molar fraction of 2,5-furandicarboxylic acid. Under nitrogen protection, the reaction was stirred at 170 °C for 1 h, at 180 °C for 1 h, at 190 °C for 1 h, and at 210 °C for 2.5 h to form a prepolymer;
[0125] (2) The above-mentioned prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h, and finally polyethylene 2,5-furandicarboxylate was obtained. The inherent viscosity was measured to be 0.72 dL / g.
[0126] Comparative Example 1
[0127] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and tetrabutyl titanate was used as a catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the mixture was stirred at 170 °C for 1 h, stirred at 180 °C for 1 h, stirred at 190 °C for 1 h, and stirred at 210 °C for 2.5 h to form a prepolymer;
[0128] (2) The above-mentioned prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h, and finally polyethylene naphthalate was obtained. The inherent viscosity was measured to be 0.46 dL / g.
[0129] Comparative Example 2
[0130] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and germanium oxide was used as a catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the mixture was stirred at 170 °C for 1 h, stirred at 180 °C for 1 h, stirred at 190 °C for 1 h, and stirred at 210 °C for 2.5 h to form a prepolymer;
[0131] (2) The above-mentioned prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h, and finally polyethylene naphthalate was obtained. The inherent viscosity was measured to be 0.45 dL / g.
[0132] Comparative Example 3
[0133] 1.0 mol of 2,6-naphthalenedicarboxylic acid and 1.6 mol of ethylene glycol were added to a reaction flask, and titanium dioxide was used as a catalyst, accounting for 0.1% of the molar fraction of 2,6-naphthalenedicarboxylic acid. Under nitrogen protection, the mixture was stirred at 170 °C for 1 h, stirred at 180 °C for 1 h, stirred at 190 °C for 1 h, and stirred at 210 °C for 2.5 h to form a prepolymer;
[0134] (2) The above-mentioned prepolymer was evacuated to 107.6 Pa and stirred at 240 °C for 4 h, and finally polyethylene naphthalate was obtained. The inherent viscosity was measured to be 0.49 dL / g.
[0135] As described above, these are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the relevant art can make some changes or modifications within the scope of the technical solution of the present application by using the disclosed technical content, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.
Claims
1. A rare earth element-doped titanium dioxide nanoparticle catalyst, characterized in that, The rare earth element-doped titanium dioxide nanoparticle catalyst comprises titanium dioxide and a rare earth element doped in the titanium dioxide; The rare earth element is selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium; The diameter of the rare earth element-doped titanium dioxide nanoparticle catalyst is 1 to 100 nm.
2. The rare earth element-doped titanium dioxide nanoparticle catalyst according to claim 1, characterized in that, The doping amount of the rare earth element in the rare earth element-doped titanium dioxide nanoparticle catalyst is 0.09 wt% to 20 wt%.
3. A method for preparing the rare earth element-doped titanium dioxide nanoparticle catalyst according to any one of claims 1 to 2, characterized in that, The preparation method includes: Reacting, drying, and calcining a mixture containing a titanium salt, a rare earth element salt, citric acid, ethylenediamine, ethanol, and hydrofluoric acid to obtain the rare earth element-doped titanium dioxide nanoparticle catalyst.
4. The preparation method according to claim 3, characterized in that, The titanium salt is selected from at least one of titanium sulfate, titanium chloride, titanium tetrachloride, titanium oxysulfate, tetrabutyl titanate, and tetraisopropyl titanate; Preferably, the rare earth element salt is selected from at least one of a chloride, nitrate, or sulfate containing a rare earth element; Preferably, the gadolinium source accounts for 0.01% to 2% of the molar amount of the titanium source; Preferably, the molar ratio of the titanium source, citric acid, ethylenediamine, absolute ethanol, and hydrofluoric acid is: (0.0005 to 0.002):(0.002 to 0.004):(0.1 to 0.15):(0.13 to 0.18):(0.008 to 0.01).
5. The preparation method according to claim 3, characterized in that, The temperature of the reaction is 100 to 200 °C, and the reaction time is 1 to 10 h; Preferably, the temperature of the drying is 30 to 80 °C, and the drying time is 3 to 15 h; Preferably, the temperature of the calcining is 300 to 600 °C, and the calcining time is 3 to 10 h.
6. A method for preparing a polyester, characterized in that, The preparation method includes: (1) Under an inert atmosphere, reacting a mixture containing a dibasic acid, a diol, and a catalyst in Reaction I to obtain a prepolymer; (2) Performing Reaction II on the prepolymer to obtain the polyester; The catalyst is selected from the rare earth element-doped titanium dioxide nanoparticle catalysts described in any one of claims 1 to 2.
7. The preparation method according to claim 6, characterized in that, The dibasic acid is selected from at least one of 1,4-butanedioic acid, 1,3-butanedioic acid, 1,5-pentanedioic acid, 3,4-furandicarboxylic acid, 3,4-thiophenedicarboxylic acid, 1,6-hexanedioic acid, oxalic acid, malonic acid, 1,7-heptanedioic acid, 1,8-octanedioic acid, terephthalic acid, isophthalic acid, 1,9-nonanedioic acid, 1,10-decanedioic acid, 1,11-undecanedioic acid, 1,12-dodecanedioic acid, 2,5-thiophenedicarboxylic acid, 2,4-thiophenedicarboxylic acid, 1,13-tridecanedioic acid, 2,4-furandicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; Preferably, the diol is selected from at least one of ethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,8-octanediol, 1,9-nonanediol, 2,3-butanediol, 1,5-pentanediol, 1,7-heptanediol, 1,10-decanediol, 1,2-propanediol, 1,6-hexanediol, isosorbide, 1,4-butanediol, 1,4-cyclohexanediol, 1,3-cyclobutanedimethanol, 1,4-cyclohexanedimethanol, and polyethylene glycol; Preferably, the dosage of the rare earth element-doped titanium dioxide nanoparticle catalyst is 0.01 to 2% of the molar amount of the dibasic acid; Preferably, the molar ratio of the diol to the dibasic acid is 1 to 3:
1.
8. The preparation method according to claim 6, characterized in that, In the step (1), the temperature of the reaction I is 100 to 250 °C, and the time of the reaction I is 0.5 to 5 h; Preferably, the inert atmosphere is selected from at least one of nitrogen, helium, neon or argon.
9. The preparation method according to claim 6, characterized in that, In the step (2), the pressure of the reaction II is 10 to 110 Pa.
10. The preparation method according to claim 6, characterized in that, In the step (2), the temperature of the reaction II is 120 to 300 °C, and the time of the reaction II is 0.5 to 10 h.